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1
Pascual-Jose, B., Alireza Zare, Silvia De la Flor, José Antonio Reina, M. Giamberini, and A. Ribes-Greus. "Dielectric Properties in Oriented and Unoriented Membranes Based on Poly(Epichlorohydrin-co-Ethylene Oxide) Copolymers: Part III." Polymers 14, no. 7 (March 28, 2022): 1369. http://dx.doi.org/10.3390/polym14071369.
Повний текст джерелаАнотація:
The dielectric spectra and conductivity properties of neat poly(epichlorohydrin-co-ethylene oxide)(PECH-co-EO) copolymer and two modified copolymers with a 20% or 40% of dendron 3,4,5-tris[4-(n-dodecan-1-yloxy)benzyloxy] benzoate units were analysed. A process of thermal orientation was applied to the copolymers to fine-tune the molecular motion of the side chains and determine their validity for cation transport materials. The study was conducted using Dielectric Thermal Analysis (DETA). The spectra of the modified unoriented and oriented copolymers consisted of five dielectric relaxations (δ, γ, β, αTg, and αmelting). The analysis of the relaxations processes shows that as the grafting with the dendron units increases, both the lateral and main chains have a greater difficulty moving. The thermal orientation induces in the main chain partial crystallization, including the polyether segments, and modifies the cooperative motion of the main chain associated with the glass transition (αTg). A deep analysis of the electrical loss modulus revealed that the degree of modification only modifies the temperature peak of each relaxation, and this effect is more perceived if the dendron unit content is higher (40%). The thermal orientation process seems equal to the spectra of CP20-O and CP40-O to the point that the degree of modification does not matter. Nevertheless, the fragility index denotes the differences in the molecular motion between both copolymers (40% and 20%) due to the thermal orientation. The study of the electric conductivity showed that the ideal long-range pathways were being altered by neither the thermal orientation process nor the addition of dendrimers. The analysis of the through-plane proton conductivity confirmed that the oriented copolymer with the highest concentration of dendrimers was the best performer and the most suitable copolymer for proton transport materials.
2
Seo, Hyeon Myeong, Jin Ho Park, Trung Dung Dao, and Han Mo Jeong. "Compatibility of Functionalized Graphene with Polyethylene and Its Copolymers." Journal of Nanomaterials 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/805201.
Повний текст джерелаАнотація:
The compatibility of polyethylene (PE) with a functionalized graphene sheet (FGS), which was prepared by the thermal reduction of graphite oxide, was examined in this study. The dispersion of the FGS in the PE was improved as the molecular weight of the PE was decreased. The PE copolymers containing polar comonomers such as maleic anhydride or acrylic acid exhibited better compatibility with FGS than the PE homopolymers. The compatibility of the FGS with PE copolymers containing small amounts of comonomers, which have a solubility parameter slightly larger [up to approximately 0.5 (J/cm3)1/2] than that of PE itself, was better than the compatibility of both the PE and PE copolymers containing larger amounts of comonomers. The morphology, electric conductivity, and tensile properties of FGS/PE copolymer/PE nanocomposites showed that the copolymers with a solubility parameter slightly larger than that of PE effectively served as a compatibilizer in FGS/PE nanocomposites.
3
Sandu, Viorel, Stelian Popa, Ion Ivan, Carmen Plapcianu, Elena Sandu, Camelia Mihailescu, and Florica Doroftei. "Fabrication and Transport Properties of Manganite-Polyacrylamide-Based Composites." Journal of Nanomaterials 2009 (2009): 1–5. http://dx.doi.org/10.1155/2009/429430.
Повний текст джерелаАнотація:
We present the fabrication and transport properties of a series of composites made ofLa2/3Sr1/3MnO3and acrylamide-based copolymers. The most important result is the very narrow transition, of only 27 K, displayed by the peak that appears around the metal-insulator transition of the composites made with poly(acrylamide-vinylacetate). Although the amount of polymer is rather low, different copolymers change drastically the electric transport characteristics.
4
Eesaee, Mostafa, Eric David, Nicole R. Demarquette, and Davide Fabiani. "Electrical Breakdown Properties of Clay-Based LDPE Blends and Nanocomposites." Journal of Nanomaterials 2018 (2018): 1–17. http://dx.doi.org/10.1155/2018/7921725.
Повний текст джерелаАнотація:
Microstructure and electrical breakdown properties of blends and nanocomposites based on low-density polyethylene (LDPE) have been discussed. A series of LDPE nanocomposites containing different amount of organomodified montmorillonite (clay) with and without compatibilizer have been prepared by means of melt compounding. Two sets of blends of LDPE with two grades of Styrene-Ethylene-Butylene-Styrene block copolymers have been prepared to form cocontinuous structure and host the nanoreinforcement. A high degree of dispersion of oriented clay was observed through X-ray diffraction, scanning, and transmission electron microscopy. This was confirmed by the solid-like behavior of storage modulus in low frequencies in rheological measurement results. An alteration in the morphology of blends was witnessed upon addition of clay where the transportation phenomenon to the copolymer phase resulted in a downsizing on the domain size of the constituents of the immiscible blends. The AC breakdown strength of nanocomposites significantly increased when clay was incorporated. The partially exfoliated and intercalated clay platelets are believed to distribute the electric stress and prolong the breakdown time by creating a tortuous path for charge carriers. However, the incorporation of clay has been shown to diminish the DC breakdown strength of nanocomposites, mostly due to the thermal instability brought by clay.
5
Cho, Kie Yong, Ara Cho, Hyun-Ji Kim, Sang-Hee Park, Chong Min Koo, Young Je Kwark, Ho Gyu Yoon, Seung Sang Hwang, and Kyung-Youl Baek. "Control of hard block segments of methacrylate-based triblock copolymers for enhanced electromechanical performance." Polymer Chemistry 7, no. 48 (2016): 7391–99. http://dx.doi.org/10.1039/c6py01868h.
Повний текст джерелаАнотація:
A series of well-defined hard–soft–hard triblock copolymers with various hard block segments were synthesized by Ru-based atom transfer radical polymerization (ATRP) (MWD < 1.26) in order to examine their electromechanical properties under electric fields.
6
Nurabay, Nazerke, M. Abutalip, Raikhan Rakhmetullayeva, and Grigoriy Mun. "Development of the technology for obtaining new hydrogel materials based on acrylic monomers." Chemical Bulletin of Kazakh National University, no. 4 (December 27, 2017): 20–29. http://dx.doi.org/10.15328/cb959.
Повний текст джерелаАнотація:
Smart water-soluble polymers and hydrogels are capable to reversibly react to insignificant changes of the medium properties (pH, temperature, ionic strength, a presence of some substances, illumination, electric field). The reacting of a system is visible to the naked eye (the formation of a new phase in a homogeneous solution, or compression of the hydrogel). The properties of such polymers and hydrogels are considered. For the first time, the stimuli-responsive polymeric hydrogels based on N-isopropylacrylamide (NIPAAM), 2-hydroxyethyl acrylate (HEA) and acrylic acid (AA) have been synthesized by free initiation of radical copolymerization. The purpose of the research is to obtain stimuli-responsive cross-linked terpolymers based on N-isopropylacrylamide, 2-hydroxyethyl acrylate and acrylic acid and study their physicochemical properties. The physicochemical methods such as scanning electron microscopy, differential scanning calorimetry, infrared spectroscopy, gravimetry, cathetometric and thermogravimetric analyses were used in this study. To determine the thermal and pH – sensitivity of the modified copolymer, the effect of temperature on the NIPAAM-НEA-AA nets (in different pH media) was studied. They are characterized by a thermally induced collapse and a dependence on a medium pH. The interaction of copolymers with drugs such as lincomycin and gentamicin was studied for using the new copolymers as a drug carrier. To study the antibacterial properties and the transportation of physiologically active substances of hydrogel, the elimination of specially prepared bacteria by hydrogels with various medicinal ingredients were conducted.
7
Chávez-Castillo, Marilú, Arelis Ledesma-Juárez, Marisol Güizado-Rodríguez, Jesús Castrellón-Uribe, Gabriel Ramos-Ortiz, Mario Rodríguez, José-Luis Maldonado, Jorge-Antonio Guerrero-Álvarez, and Victor Barba. "Third-Order Nonlinear Optical Behavior of Novel Polythiophene Derivatives Functionalized with Disperse Red 19 Chromophore." International Journal of Polymer Science 2015 (2015): 1–10. http://dx.doi.org/10.1155/2015/219361.
Повний текст джерелаАнотація:
Two copolymers of 3-alkylthiophene (alkyl = hexyl, octyl) and a thiophene functionalized with disperse red 19 (TDR19) as chromophore side chain were synthesized by oxidative polymerization. The synthetic procedure was easy to perform, cost-effective, and highly versatile. The molecular structure, molecular weight distribution, film morphology, and optical and thermal properties of these polythiophene derivatives were determined by NMR, FT-IR, UV-Vis GPC, DSC-TGA, and AFM. The third-order nonlinear optical response of these materials was performed with nanosecond and femtosecond laser pulses by using the third-harmonic generation (THG) andZ-scan techniques at infrared wavelengths of 1300 and 800 nm, respectively. From these experiments it was observed that although the TRD19 incorporation into the side chain of the copolymers was lower than 5%, it was sufficient to increase their nonlinear response in solid state. For instance, the third-order nonlinear electric susceptibility (χ3) of solid thin films made of these copolymers exhibited an increment of nearly 60% when TDR19 incorporation increased from 3% to 5%. In solution, the copolymers exhibited similar two-photon absorption cross sectionsσ2PAwith a maximum value of 8545 GM and 233 GM (1 GM = 10−50 cm4 s) per repeated monomeric unit.
8
Neyolova, O. V., L. M. Kubalova, and T. A. Panova. "Polyorganosiloxane block-copolymers with linear-ladder structure, intended for production of heat-resistant protective coatings." Adhesives. Sealants. Technologias, no. 11 (2021): 2–11. http://dx.doi.org/10.31044/1813-7008-2021-0-11-2-11.
Повний текст джерелаАнотація:
The development possibility of new organic-silicon compounds based on solutions of linear-ladder block-copolymers in an organic dissolvent, allowing one to produce heat-resistant electric insulating elastomer coatings possessing optimal physical-chemical properties, has been studied. The compounds are intended for production of heat-resistant protective coatings used in the electronic and radio-engineering instrument making, as well as for the thermal protection of products of aircraft building, rocket production, machine building and other equipment
9
Mayer, Alexander, Dominik Steinle, Stefano Passerini, and Dominic Bresser. "Block copolymers as (single-ion conducting) lithium battery electrolytes." Nanotechnology 33, no. 6 (November 15, 2021): 062002. http://dx.doi.org/10.1088/1361-6528/ac2e21.
Повний текст джерелаАнотація:
Abstract Solid-state batteries are considered the next big step towards the realization of intrinsically safer high-energy lithium batteries for the steadily increasing implementation of this technology in electronic devices and particularly, electric vehicles. However, so far only electrolytes based on poly(ethylene oxide) have been successfully commercialized despite their limited stability towards oxidation and low ionic conductivity at room temperature. Block copolymer (BCP) electrolytes are believed to provide significant advantages thanks to their tailorable properties. Thus, research activities in this field have been continuously expanding in recent years with great progress to enhance their performance and deepen the understanding towards the interplay between their chemistry, structure, electrochemical properties, and charge transport mechanism. Herein, we review this progress with a specific focus on the block-copolymer nanostructure and ionic conductivity, the latest works, as well as the early studies that are fr"equently overlooked by researchers newly entering this field. Moreover, we discuss the impact of adding a lithium salt in comparison to single-ion conducting BCP electrolytes along with the encouraging features of these materials and the remaining challenges that are yet to be solved.
10
Sandu, Viorel, Stelian Popa, C. Plapcianu, Elena Sandu, N. Hurduc, and I. Nor. "Transport and Magnetic Properties of CrO2-Polymer Magnetic Composites." Advanced Materials Research 47-50 (June 2008): 326–30. http://dx.doi.org/10.4028/www.scientific.net/amr.47-50.326.
Повний текст джерелаАнотація:
We report the transport and magnetic properties of sintered CrO2-polymer composites. In order to improve the elastic properties of the CrO2-based composites, we investigated two types of styrene-based copolymers: poly(methyl methacrylate)-styrene (9/1 and 5/5) and linear polysiloxaneg- styrene as well as poly(methyl methacrylate)–butadiene 9/1. The electric transport and magnetoresistance are consistent with the spin tunneling model at low temperatures but the contribution of spin independent channels becomes important at high temperature and high fields. All composites display ferromagnetism at room temperature with saturation at low fields and a slightly temperature-dependent coercive field for the samples grafted either with butadiene or with styrene except for CrO2-polysiloxane-g-styrene composite where it exponentially decreases with increasing temperature.
11
Grigorescu, Ramona Marina, Paul Ghioca, Lorena Iancu, Madalina Elena Grigore, Ramona Elena Andrei, Rodica Mariana Ion, Cristian Andi Nicolae, and Raluca Gabor. "Composites of Styrene-butadiene Block-copolymers Reinforced with WEEE Polystyrene Fraction." Materiale Plastice 56, no. 3 (September 30, 2019): 510–13. http://dx.doi.org/10.37358/mp.19.3.5219.
Повний текст джерелаАнотація:
The high global production of electric and electronic equipment increases in the same manner the amount of the waste that needs to be recycled. Special attention is given to the plastics recycling from the waste in addition to the metals recovery that brings economic advantages. Considering that the plastic amount contains about 80% polystyrene polymers, the paper presents a recycling study of this fraction as reinforcing agent for a styrene-butadiene block copolymer. In order to reduce the melt viscosity, some of the composites were extended with paraffin-naphthenic �heavy white oil�. The blends were characterized by mechanical testing, thermal and dynamo-mechanical analysis. Based on the resulted properties, it can be concluded that the extended and reinforced composites can be used as material for shoe soles.
12
Surtchev, Marko, Sergey Belikov, Ivan Malovichko, and Sergei Magonov. "Comprehensive Characterization of Neat Polymers and Compositional Imaging Heterogeneous Polymer Systems with AFM Based Mechanical, Electric and Spectroscopic Methods." MRS Proceedings 1754 (2015): 75–80. http://dx.doi.org/10.1557/opl.2015.199.
Повний текст джерелаАнотація:
ABSTRACTComprehensive characterization of materials suggests measuring their different properties for optimal use in technological applications and this task becomes more challenging as size of related structures decreases and their complexity increases. At smaller scales Atomic Force Microscopy (AFM) enables visualization of structures and quantitative measurements of their mechanical and electric properties. So far, several properties such as elastic modulus and work of adhesion, surface potential and dielectric permittivity can be extracted from the results obtained in various AFM modes. More complicated are the AFM experiments and their analysis in case of viscoelastic, piezoelectric and thermoelectric properties. Several examples of quantitative characterization of neat polymers will be given. In many cases the dissimilarity of the components’ properties is employed for their recognition in heterogeneous systems such as polymer blends, block copolymers and metal alloys. The confined geometries, which are common for small-scale structures, might restrict such identification and a combination of AFM with spectral methods such as Raman scattering will be helpful. Achievements and challenges of compositional mapping will be illustrated on several complex materials.
13
Pozhidaev, Evgenii D., Vera V. Shaposhnikova, Alexey R. Tameev, and Andrey E. Abrameshin. "Radiation-Induced Transient Currents in Films of Poly(arylene ether ketone) Including Phthalide Moiety." Polymers 12, no. 1 (December 19, 2019): 13. http://dx.doi.org/10.3390/polym12010013.
Повний текст джерелаАнотація:
The electrical properties of thin films of poly(arylene ether ketone) copolymers (co-PAEKs) with a fraction of phthalide-containing units of 3, 5, and 50 mol% in the main chain were investigated by using radiation-induced conductivity (RIC) measurements. Transient current signals and current-voltage (I-V) characteristics were obtained by exposing 20 ÷ 25 μm thick films of the co-PAEKs to monoenergetic electron pulses with energy ranging from 3 to 50 keV in an electric field ranging from 5 to 40 V/μm. The Rose-Fowler-Vaisberg semi-empirical model based on a multiple trapping formalism was used for an analysis of the RIC data, and the parameters of the highly dispersive charge carrier transport were evaluated. The analysis revealed that charge carriers moved in isolation from each other, and the applied electric fields were below the threshold field triggering the switching effect (a reversible high-to-low resistivity transition) in the co-PAEK films. It was also found that the co-PAEK films, due to the super-linear I-V characteristics, are highly resistant to electrostatic discharges arising from the effects of ionizing radiation. This property is important for the development of protective coatings for electronic devices.
14
Guan, Fangxiao, Lianyun Yang, Jing Wang, Bing Guan, Kuo Han, Qing Wang, and Lei Zhu. "Confined Ferroelectric Properties in Poly(Vinylidene Fluoride-co-Chlorotrifluoroethylene)-graft-Polystyrene Graft Copolymers for Electric Energy Storage Applications." Advanced Functional Materials 21, no. 16 (July 15, 2011): 3176–88. http://dx.doi.org/10.1002/adfm.201002015.
Повний текст джерела
15
Otero Navas, Ivonne, Milad Kamkar, Mohammad Arjmand, and Uttandaraman Sundararaj. "Morphology Evolution, Molecular Simulation, Electrical Properties, and Rheology of Carbon Nanotube/Polypropylene/Polystyrene Blend Nanocomposites: Effect of Molecular Interaction between Styrene-Butadiene Block Copolymer and Carbon Nanotube." Polymers 13, no. 2 (January 11, 2021): 230. http://dx.doi.org/10.3390/polym13020230.
Повний текст джерелаАнотація:
This work studied the impact of three types of styrene-butadiene (SB and SBS) block copolymers on the morphology, electrical, and rheological properties of immiscible blends of polypropylene:polystyrene (PP:PS)/multi-walled carbon nanotubes (MWCNT) with a fixed blend ratio of 70:30 vol.%. The addition of block copolymers to PP:PS/MWCNT blend nanocomposites produced a decrease in the droplet size. MWCNTs, known to induce co-continuity in PP:PS blends, did not interfere with the copolymer migration to the interface and, thus, there was morphology refinement upon addition of the copolymers. Interestingly, the addition of the block copolymers decreased the electrical resistivity of the PP:PS/1.0 vol.% MWCNT system by 5 orders of magnitude (i.e., increase in electrical conductivity). This improvement was attributed to PS Droplets-PP-Copolymer-Micelle assemblies, which accumulated MWCNTs, and formed an integrated network for electrical conduction. Molecular simulation and solubility parameters were used to predict the MWCNT localization in the immiscible blend. The simulation results showed that diblock copolymers favorably interact with the nanotubes in comparison to the triblock copolymer, PP, and PS. However, the interaction between the copolymers and PP or PS is stronger than the interaction of the copolymers and MWCNTs. Hence, the addition of copolymer also changed the localization of MWCNT from PS to PS–PP–Micelles–Interface, as observed by TEM images. In addition, in the last step of this work, we investigated the effect of the addition of copolymers on inter- and intra-cycle viscoelastic behavior of the MWCNT incorporated polymer blends. It was found that addition of the copolymers not only affects the linear viscoelasticity (e.g., increase in the value of the storage modulus) but also dramatically impacts the nonlinear viscoelastic behavior under large deformations (e.g., higher distortion of Lissajous–Bowditch plots).]
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Otero Navas, Ivonne Otero, Milad Kamkar, Mohammad Arjmand, and Uttandaraman Sundararaj. "Morphology Evolution, Molecular Simulation, Electrical Properties, and Rheology of Carbon Nanotube/Polypropylene/Polystyrene Blend Nanocomposites: Effect of Molecular Interaction between Styrene-Butadiene Block Copolymer and Carbon Nanotube." Polymers 13, no. 2 (January 11, 2021): 230. http://dx.doi.org/10.3390/polym13020230.
Повний текст джерелаАнотація:
This work studied the impact of three types of styrene-butadiene (SB and SBS) block copolymers on the morphology, electrical, and rheological properties of immiscible blends of polypropylene:polystyrene (PP:PS)/multi-walled carbon nanotubes (MWCNT) with a fixed blend ratio of 70:30 vol.%. The addition of block copolymers to PP:PS/MWCNT blend nanocomposites produced a decrease in the droplet size. MWCNTs, known to induce co-continuity in PP:PS blends, did not interfere with the copolymer migration to the interface and, thus, there was morphology refinement upon addition of the copolymers. Interestingly, the addition of the block copolymers decreased the electrical resistivity of the PP:PS/1.0 vol.% MWCNT system by 5 orders of magnitude (i.e., increase in electrical conductivity). This improvement was attributed to PS Droplets-PP-Copolymer-Micelle assemblies, which accumulated MWCNTs, and formed an integrated network for electrical conduction. Molecular simulation and solubility parameters were used to predict the MWCNT localization in the immiscible blend. The simulation results showed that diblock copolymers favorably interact with the nanotubes in comparison to the triblock copolymer, PP, and PS. However, the interaction between the copolymers and PP or PS is stronger than the interaction of the copolymers and MWCNTs. Hence, the addition of copolymer also changed the localization of MWCNT from PS to PS–PP–Micelles–Interface, as observed by TEM images. In addition, in the last step of this work, we investigated the effect of the addition of copolymers on inter- and intra-cycle viscoelastic behavior of the MWCNT incorporated polymer blends. It was found that addition of the copolymers not only affects the linear viscoelasticity (e.g., increase in the value of the storage modulus) but also dramatically impacts the nonlinear viscoelastic behavior under large deformations (e.g., higher distortion of Lissajous–Bowditch plots).
17
Guzmán Rodríguez, Andy Guzmán, Marquiza Sablón Sablón Carrazana, Chrislayne Rodríguez Rodríguez Tanty, Martijn J. A. Malessy, Gastón Fuentes, and Luis J. Cruz. "Smart Polymeric Micelles for Anticancer Hydrophobic Drugs." Cancers 15, no. 1 (December 20, 2022): 4. http://dx.doi.org/10.3390/cancers15010004.
Повний текст джерелаАнотація:
Cancer has become one of the deadliest diseases in our society. Surgery accompanied by subsequent chemotherapy is the treatment most used to prolong or save the patient’s life. Still, it carries secondary risks such as infections and thrombosis and causes cytotoxic effects in healthy tissues. Using nanocarriers such as smart polymer micelles is a promising alternative to avoid or minimize these problems. These nanostructured systems will be able to encapsulate hydrophilic and hydrophobic drugs through modified copolymers with various functional groups such as carboxyls, amines, hydroxyls, etc. The release of the drug occurs due to the structural degradation of these copolymers when they are subjected to endogenous (pH, redox reactions, and enzymatic activity) and exogenous (temperature, ultrasound, light, magnetic and electric field) stimuli. We did a systematic review of the efficacy of smart polymeric micelles as nanocarriers for anticancer drugs (doxorubicin, paclitaxel, docetaxel, lapatinib, cisplatin, adriamycin, and curcumin). For this reason, we evaluate the influence of the synthesis methods and the physicochemical properties of these systems that subsequently allow an effective encapsulation and release of the drug. On the other hand, we demonstrate how computational chemistry will enable us to guide and optimize the design of these micelles to carry out better experimental work.
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Abdolmaleki, Hamed, та Shweta Agarwala. "PVDF-BaTiO3 Nanocomposite Inkjet Inks with Enhanced β-Phase Crystallinity for Printed Electronics". Polymers 12, № 10 (21 жовтня 2020): 2430. http://dx.doi.org/10.3390/polym12102430.
Повний текст джерелаАнотація:
Polyvinylidene difluoride (PVDF) and its copolymers are promising electroactive polymers showing outstanding ferroelectric, piezoelectric, and pyroelectric properties in comparison with other organic materials. They have shown promise for applications in flexible sensors, energy-harvesting transducers, electronic skins, and flexible memories due to their biocompatibility, high chemical stability, bending and stretching abilities. PVDF can crystallize at five different phases of α, β, γ, δ, and ε; however, ferro-, piezo-, and pyroelectric properties of this polymer only originate from polar phases of β and γ. In this research, we reported fabrication of PVDF inkjet inks with enhanced β-phase crystallinity by incorporating barium titanate nanoparticles (BaTiO3). BaTiO3 not only acts as a nucleating agent to induce β-phase crystallinity, but it also improves the electric properties of PVDF through synergistic a ferroelectric polarization effect. PVDF-BaTiO3 nanocomposite inkjet inks with different BaTiO3 concentrations were prepared by wet ball milling coupled with bath ultrasonication. It was observed that the sample with 5 w% of BaTiO3 had the highest β-phase crystallinity, while in higher ratios overall crystallinity deteriorated progressively, leading to more amorphous structures.
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Waware, Umesh S., and Mohd Rashid. "Synthesis and characterization of electrically conducting copolymers of poly(aniline-co-o-iodoaniline)." Functional Materials Letters 07, no. 05 (August 26, 2014): 1450062. http://dx.doi.org/10.1142/s1793604714500623.
Повний текст джерелаАнотація:
Functionalized copolymers of poly(aniline-co-o-iodoaniline) have been synthesized by the chemical oxidative polymerization method by using o-iodoaniline (o-IA) and aniline (AN) as monomer units by changing their molar feed ratio in acid aqueous medium. The physical properties viz; solubility, electrical conductivity have been studied to characterize them. The copolymers possess better solubility than unsubstituted homopolymer in organic solvent such as N -methyl-2-pyrrodinone (NMP). The conductivity of the pressed pellets of as-synthesized copolymers depends upon the content of o-IA in the polyaniline (PANI). The structural confirmation of the copolymer has been explained by Fourier transform infrared spectroscopy study which suggest that AN and o-IA units are uniformly distributed along the polymer chain and thus, the physical properties of copolymers may possibly be tailored by varying the molar feed ratio in copolymerization reactions. The conductivity of the copolymer decreases upon increasing the o-IA content in molar feed, because the introduction of –I- as a functional group reduces the extent of conjugation of the polymer chain.
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Açıkses, Aslışah, Necmittin Çömez, and Fatih Biryan. "Preparation and Characterization of Styrene Bearing Diethanolamine Side Group, Styrene Copolymer Systems, and Their Metal Complexes." International Journal of Polymer Science 2018 (2018): 1–15. http://dx.doi.org/10.1155/2018/6703783.
Повний текст джерелаАнотація:
The two copolymer systems of styrene bearing diethanol amine side group and styrene were prepared by free radical polymerization method at 60°C in presence of 1,4-dioxane as solvent and AIBN as initiator. Their metal complexes were prepared by reaction of the copolymer used as ligand P(DEAMSt-co-St)L′′ and Ni(II) and Co(II) metal ions, which was carried out in presence of ethanol and NaOH at 65°C for 48 h in pH = 7.5. The structures of the copolymers used as ligand and metal complexes were identified by FT-IR, 1H-NMR spectra, and elemental analysis. The properties of the copolymers used as ligand and metal complexes were characterized by SEM-EDX, AAS, DSC, TGA, and DTA techniques. Then, the electrical properties of the copolymers and metal complexes were examined as a function of the temperature and frequency, and the activation energies (Ea) were estimated with conductivity measurements.
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Abu Hassan Shaari, Helyati, Muhammad Mahyiddin Ramli, Mohd Mustafa Al Bakri Abdullah, Mohd Nazim Mohtar, Norizah Abdul Rahman, Azizan Ahmad, Nurul Huda Osman, and Febdian Rusydi. "Effects of Polymerization Time towards Conductivity and Properties of Poly(methyl methacrylate)/Polyaniline (PMMA/PANi) Copolymer." Sustainability 14, no. 14 (July 21, 2022): 8940. http://dx.doi.org/10.3390/su14148940.
Повний текст джерелаАнотація:
The effects of various polymerization times on the properties and conductivity of poly(methyl methacrylate)/polyaniline (PMMA/PANi) copolymer has been investigated. Different polymerization times, such as 1 h, 2 h, and 3 h, have been employed during free radical copolymerization of PMMA/PANi copolymer. The properties of newly synthesized PMMA/PANi copolymer were discussed with the help of Fourier transform infrared (FTIR), 1H nuclear magnetic resonance (NMR) spectroscopies, UV-Vis spectroscopy, and transmission electron microscopy. All copolymers showed electrical conductivity of a semi-conductor material, compared with PMMA itself. It was found that the reaction played a significant role, especially at optimum polymerization time, where PANi formation and conductivity was at its highest. Our present work demonstrates that copolymer film could be a promising material to fabricate polymer conducting film in many electronics applications.
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Ivankin, A. N., A. N. Zarubina, A. S. Kulezenev, V. A. Kochetkov, and A. V. Ustyugov. "Polyelectrolyte sealant for fuel elements, based on grafted fluorocopolymers." Adhesives. Sealants. Technologias, no. 8 (2021): 12–16. http://dx.doi.org/10.31044/1813-7008-2021-0-8-12-16.
Повний текст джерелаАнотація:
The preparation of grafted copolymers for electrochemical devices by chemical grafting copolymerization of acrylic acid and α-, β-, β-trifluorostyrene to a film fluorinated copolymer of hexafluoropropylene with vinylidene fluoride is described. The grafted copolymers contained carboxyl groups and the sulfonation process was carried out for additional introduction of ionic sulfo- groups. The optimal conditions for the process have been determined, which make possible to obtain grafted copolymers with a wide range of electrochemical and physical-mechanical properties. The resulting products in the form of ion-conducting membranes can be used as part of current sources and other electrochemical devices and have a specific volumetric electrical resistance of 0.46—1.41 Ohm.m, exchange capacity 1.45—1.62 meq / g, moisture content 25—62%, breaking stress 0.82—1.08 MPa.
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Bustamante-Torres, Moises, David Romero-Fierro, Belén Arcentales-Vera, Kenia Palomino, Héctor Magaña, and Emilio Bucio. "Hydrogels Classification According to the Physical or Chemical Interactions and as Stimuli-Sensitive Materials." Gels 7, no. 4 (October 25, 2021): 182. http://dx.doi.org/10.3390/gels7040182.
Повний текст джерелаАнотація:
Hydrogels are attractive biomaterials with favorable characteristics due to their water uptake capacity. However, hydrogel properties are determined by the cross-linking degree and nature, the tacticity, and the crystallinity of the polymer. These biomaterials can be sorted out according to the internal structure and by their response to external factors. In this case, the internal interaction can be reversible when the internal chains are led by physicochemical interactions. These physical hydrogels can be synthesized through several techniques such as crystallization, amphiphilic copolymers, charge interactions, hydrogen bonds, stereo-complexing, and protein interactions. In contrast, the internal interaction can be irreversible through covalent cross-linking. Synthesized hydrogels by chemical interactions present a high cross-linking density and are employed using graft copolymerization, reactive functional groups, and enzymatic methods. Moreover, specific smart hydrogels have also been denoted by their external response, pH, temperature, electric, light, and enzyme. This review deeply details the type of hydrogel, either the internal structure or the external response. Furthermore, we detail some of the main applications of these hydrogels in the biomedicine field, such as drug delivery systems, scaffolds for tissue engineering, actuators, biosensors, and many other applications.
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Soriano-Corral, F., L. F. Ramos-de Valle, F. J. Enríquez-Medrano, P. A. De León-Martínez, M. L. López-Quintanilla, and E. N. Cabrera-Álvarez. "Cast Nanostructured Films of Poly(methyl methacrylate-b-butyl acrylate)/Carbon Nanotubes: Influence of Poly(butyl acrylate) Content on Film Evaporation Rate, Morphology, and Electrical Resistance." Journal of Nanomaterials 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/352937.
Повний текст джерелаАнотація:
Nanocomposites of poly(methyl methacrylate-b-butyl acrylate)/multiwalled carbon nanotubes were prepared from different copolymers synthesized by RITP technique using iodine functionalized poly(methyl methacrylate) as macrochain transfer agent to obtain block copolymers with butyl acrylate as comonomer in a sequential copolymerization. Poly(butyl acrylate) contents of 7, 20, and 30 wt% were attained in each copolymer. These copolymers were used to prepare nanostructured films by casting process, using chloroform as solvent, and carboxyl functionalized MWCNT at 0.4, 0.6, 0.8, 1.0, and 1.2 wt%. During the film preparation, the absolute drying rate (N) was calculated with respect to the poly(butyl acrylate) and MWCNT composition. For copolymers containing 7 and 20 wt% of poly(butyl acrylate) theNvalues slightly decrease with the MWCNT concentration, while for the suspension prepared with the copolymer at 30 wt% of poly(butyl acrylate) theNvalues decrease drastically down to 50% approximately. The MWCNT content at the percolation threshold point was found to be 0.8 wt%, for all nanostructured films. The dispersion of MWCNT within the polymer matrix decreased with increasing the poly(butyl acrylate) composition, but it did not affect the electrical properties, which is assumed to be due to induction of the bridging effect and the MWCNT preference to locate into the poly(methyl methacrylate) phase.
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Jeong, Hey In, Dae Hyeok An, Jun Woo Lim, Taehoon Oh, Hojin Lee, Sung-Min Park, Jae Hyun Jeong, and Jae Woo Chung. "Hydrogel Surface-Modified Polyurethane Copolymer Film with Water Permeation Resistance and Biocompatibility for Implantable Biomedical Devices." Micromachines 12, no. 4 (April 16, 2021): 447. http://dx.doi.org/10.3390/mi12040447.
Повний текст джерелаАнотація:
To use implantable biomedical devices such as electrocardiograms and neurostimulators in the human body, it is necessary to package them with biocompatible materials that protect the internal electronic circuits from the body’s internal electrolytes and moisture without causing foreign body reactions. Herein, we describe a hydrogel surface-modified polyurethane copolymer film with concurrent water permeation resistance and biocompatibility properties for application to an implantable biomedical device. To achieve this, hydrophobic polyurethane copolymers comprising hydrogenated poly(ethylene-co-butylene) (HPEB) and aliphatic poly(carbonate) (PC) were synthesized and their hydrophobicity degree and mechanical properties were adjusted by controlling the copolymer composition ratio. When 10 wt% PC was introduced, the polyurethane copolymer exhibited hydrophobicity and water permeation resistance similar to those of HPEB; however, with improved mechanical properties. Subsequently, a hydrophilic poly(vinyl pyrrolidone) (PVP) hydrogel layer was formed on the surface of the polyurethane copolymer film by Fenton reaction using an initiator and crosslinking agent and the effect of the initiator and crosslinking agent immobilization time, PVP concentration and crosslinking agent concentration on the hydrogel properties were investigated. Finally, MTT assay showed that the hydrogel surface-modified polyurethane copolymer film displays excellent biocompatibility.
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Kumara, Sarath, Xiangdong Xu, Thomas Hammarström, Yingwei Ouyang, Amir Masoud Pourrahimi, Christian Müller, and Yuriy V. Serdyuk. "Electrical Characterization of a New Crosslinked Copolymer Blend for DC Cable Insulation." Energies 13, no. 6 (March 19, 2020): 1434. http://dx.doi.org/10.3390/en13061434.
Повний текст джерелаАнотація:
To design reliable high voltage cables, clean materials with superior insulating properties capable of operating at high electric field levels at elevated temperatures are required. This study aims at the electrical characterization of a byproduct-free crosslinked copolymer blend, which is seen as a promising alternative to conventional peroxide crosslinked polyethylene currently used for high voltage direct current cable insulation. The characterization entails direct current (DC) conductivity, dielectric response and surface potential decay measurements at different temperatures and electric field levels. In order to quantify the insulating performance of the new material, the electrical properties of the copolymer blend are compared with those of two reference materials; i.e., low-density polyethylene (LDPE) and peroxide crosslinked polyethylene (XLPE). It is found that, for electric fields of 10–50 kV/mm and temperatures varying from 30 °C to 70 °C, the DC conductivity of the copolymer blend is in the range of 10−17–10−13 S/m, which is close to the conductivity of crosslinked polyethylene. Furthermore, the loss tangent of the copolymer blend is about three to four times lower than that of crosslinked polyethylene and its magnitude is on the level of 0.01 at 50 °C and 0.12 at 70 °C (measured at 0.1 mHz and 6.66 kV/mm). The apparent conductivity and trap density distributions deduced from surface potential decay measurements also confirmed that the new material has electrical properties at least as good as currently used insulation materials based on XLPE (not byproduct-free). Thus, the proposed byproduct-free crosslinked copolymer blend has a high potential as a prospective insulation medium for extruded high voltage DC cables.
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Grytsenko, Oleksandr, Ludmila Dulebova, Emil Spišák, and Bohdan Berezhnyy. "New Materials Based on Polyvinylpyrrolidone-Containing Copolymers with Ferromagnetic Fillers." Materials 15, no. 15 (July 26, 2022): 5183. http://dx.doi.org/10.3390/ma15155183.
Повний текст джерелаАнотація:
The article investigates the peculiarities of the effect of ferromagnetic fillers (FMFs) of various natures (Ni, Co, Fe, FeCo, SmCo5) on the formation of the structure and properties of 2-hydroxyethylmethacrylate (HEMA) with polyvinylpyrrolidone (PVP) copolymers. The composites were characterized using FTIR-spectroscopy, SEM, DMTA, magnetometry of vibrating samples, specific electrical resistivity studies, and mechanical and thermophysical studies. The formation of a grafted spatially crosslinked copolymer (pHEMA-gr-PVP) was confirmed and it was established that the FMF introduction of only 10 wt.% into the copolymer formulation increased the degree of crosslinking of the polymer network by three times. The surface hardness of composites increased by 20–25%. However, the water content decreased by 16–18% and lay within 42–43 wt.%, which is a relatively high number. The heat resistance of dry composites was characterized by Vicat softening temperature, which was 39–42 °C higher compared to the unfilled material. It was established that the obtained composites were characterized by a coercive force of 200 kA × m−1 and induction of a magnetic field at the poles of 4–5 mT and 10–15 mT, respectively. The introduction of FMF particles into pHEMA-gr-PVP copolymers, which, in the dry state, are dielectrics, provides them with electrical conductivity, which was evaluated by the specific volume resistance. Depending on the FMF nature and content, as well as their orientation in the magnetic field, the resistance of filled materials could be regulated within 102–106 Ohm·m. Therefore, the modification of HEMA with PVP copolymers by ferromagnetic fillers of various natures provides the possibility of obtaining materials with unique predicted properties and expands the fields of their use, for instance as magnetic sorbents for various applications, as well as the possibilities associated with their being electrically conductive materials that can respond by changing of electrical conductivity, depending on various factors.
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Elkatatny, Salaheldin. "Enhancing the Stability of Invert Emulsion Drilling Fluid for Drilling in High-Pressure High-Temperature Conditions." Energies 11, no. 9 (September 11, 2018): 2393. http://dx.doi.org/10.3390/en11092393.
Повний текст джерелаАнотація:
Drilling in high-pressure high-temperature (HPHT) conditions is a challenging task. The drilling fluid should be designed to provide high density and stable rheological properties. Barite is the most common weighting material used to adjust the required fluid density. Barite settling, or sag, is a common issue in drilling HPHT wells. Barite sagging may cause many problems such as density variations, well-control problems, stuck pipe, downhole drilling fluid losses, or induced wellbore instability. This study assesses the effect of using a new copolymer (based on styrene and acrylic monomers) on the rheological properties and the stability of an invert emulsion drilling fluid, which can be used to drill HPHT wells. The main goal is to prevent the barite sagging issue, which is common in drilling HPHT wells. A sag test was performed under static (vertical and 45° incline) and dynamic conditions in order to evaluate the copolymer’s ability to enhance the suspension properties of the drilling fluid. In addition, the effect of this copolymer on the filtration properties was performed. The obtained results showed that adding the new copolymer with 1 lb/bbl concentration has no effect on the density and electrical stability. The sag issue was eliminated by adding 1 lb/bbl of the copolymer to the invert emulsion drilling fluid at a temperature >300 °F under static and dynamic conditions. Adding the copolymer enhanced the storage modulus by 290% and the gel strength by 50%, which demonstrated the power of the new copolymer to prevent the settling of the barite particles at a higher temperature. The 1 lb/bbl copolymer’s concentration reduced the filter cake thickness by 40% at 400 °F, which indicates the prevention of barite settling at high temperature.
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BARIM, Esra. "Synthesis, Characterization, Optical and Thermal Properties of P(NVC-co-BZMA) Copolymer and Its ZnO Composites." Gazi University Journal of Science Part A: Engineering and Innovation 9, no. 4 (December 31, 2022): 526–36. http://dx.doi.org/10.54287/gujsa.1199767.
Повний текст джерелаАнотація:
Recent studies have paid particular attention to polymer-nanoparticle composite materials considering they have a number of interesting properties, which include optical, thermal, electrical, and others (Reyna-Gonzalez et al., 2009; Yakuphanoglu et al., 2010). In this study, a free radical polymerization process was used to create a copolymer of N-vinylcarbazole (NVC) and benzyl methacrylate (BZMA) at 25–75 mol% each. The procedure was conducted at 70°C with azobisisobutyronitrile (AIBN) acting as the initiator. Nano zinc oxide powders were then added to composites at three different ratios of 5%, 10%, and 15% weight of the copolymer. In order to better understand the structures of the P(NVC-co-BZMA) and its composites, FT-IR, 1H NMR, and UV spectroscopic techniques were also implemented. The optical characteristics of both the pure copolymer and its composites were examined. In the visible region, the composite containing 15% nano ZnO had the highest optical absorbance value. Additionally, the thermal behaviours of the composites and copolymers were analysed.
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Jin, Sung-Hun, and Dai-Soo Lee. "Preparation and Properties of the Nanocomposites Based on Poly(methyl methacrylate-co-butyl acrylate) and Multiwalled Carbon Nanotube." Journal of Nanoscience and Nanotechnology 8, no. 9 (September 1, 2008): 4675–78. http://dx.doi.org/10.1166/jnn.2008.ic25.
Повний текст джерелаАнотація:
Nanocomposites, based on multiwalled carbon nanotube (MWCNT) and various acrylic copolymers of poly(methyl methacrylate-co-butyl acrylate)s, were prepared and the effects of the copolymer compositions on the electrical and the dynamic mechanical properties of the nanocomposites investigated. Latices of the acrylic copolymer were prepared by emulsion polymerization, and then mixed with MWCNT dispersed in N-methylpyrrolidone to prepare the nanocomposites. The electrical resistivities of the nanocomposites showed threshold decreases with increasing MWCNT content, due to percolation. The critical MWCNT content (Pc) in the nanocomposites for percolation showed minimum with increasing butyl acrylate content within the poly(methyl methacrylate-co-butyl acrylate). Specifically, the nanocomposites of the acrylic copolymer with a butyl acrylate content of 20∼40 wt% showed the lowest Pc value of all the nanocomposites investigated. The nanocomposites showed large increases in the storage moduli in the rubbery plateau region. A decrease in the glass transition temperature (Tg) was observed with the nanocomposites and attributed to the characteristics of the nanocomposites, where the large surface area of MWCNT makes the matrix polymers similar to those of free stand thin film polymers.
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Patel, Rakesh B., Umesh P. Tarpada, and Dipak K. Raval. "A study on glass fiber reinforced composites from 2,3-epoxypropyl-3-(2-furyl) acrylate and methyl methacrylate." Journal of Polymer Engineering 34, no. 6 (August 1, 2014): 531–41. http://dx.doi.org/10.1515/polyeng-2013-0084.
Повний текст джерелаАнотація:
Abstract 2,3-Epoxypropyl-3-(2-furyl) acrylate (EPFA) was synthesized from 3-(2-furyl) acrylic acid (FAA) and epichlorohydrin, followed by copolymerization of EPFA with methyl methacrylate (MMA) by varying the mole ratio of EPFA:MMA at different reaction times using benzoyl peroxide as an initiator at 80°C in toluene. The FAA, EPFA and copolymers were characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (1H NMR) spectroscopy, viscosity measurement, gel permeation chromatography (GPC) as well as epoxy equivalent weight (EEW). Mechanical properties, electrical properties and chemical resistance of the selected glass fiber reinforced composites were determined according to the ASTM method and discussed in light of copolymer composites.
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Dolgin, Ignat S., Pyotr P. Purygin та Yury P. Zarubin. "Study of dielectric properties of 4-methylstyrene and α-methylstyrene copolymer films with different molar ratio of initial monomers". Butlerov Communications 58, № 6 (30 червня 2019): 55–58. http://dx.doi.org/10.37952/roi-jbc-01/19-58-6-55.
Повний текст джерелаАнотація:
Two new copolymers of 4-methylstyrene and α-methylstyrene were obtained by the emulsion polymerization method according to the previously described and tested method in the course of the experiment in laboratory conditions. The molar ratio of the starting monomers of 4-methylstyrene and α-methylstyrene was 9: 2 and 10: 1, respectively, in each material sample. The structure of the copolymers obtained was confirmed by IR and 1H NMR spectroscopy. Under laboratory conditions, three prototypes of each copolymer film were obtained from the solution. A sample of the copolymer was dissolved in methylene chloride was applied on a smooth glass substrate. After complete evaporation of the solvent, the film was separated from the substrate. The thickness of the films for each copolymer sample was 20, 30, and 50 microns. In the course of further experimentation, these samples were examined for the values of dielectric constant and tangent of dielectric loss angle. The basis of this experiment used a resonant method of measurement. The presented method is based on the variation of conductivity due to a change in the electrical capacitance of the oscillating circuit. In this experiment, the magnitude of the electrical capacitance and the tangent of the dielectric loss angle were measured. Based on the value of the capacitance and the parameters of the film sample to be measured, it is possible to calculate the dielectric constant. From the data obtained it can be seen that with increasing film thickness, dielectric constant values decrease. However, the indicators of the tangent of dielectric loss angle increase. With an increase in the measurement frequency, a slight decrease in the dielectric constant is observed, and the value of the tangent of the dielectric loss angle decreases nonlinearly. In addition, it should be noted that the samples of 4-methylstyrene-α-methylstyrene copolymer films with a molar ratio of starting monomers of 10: 1 have a higher dielectric constant, along with lower values of the dielectric loss tangent. From this it follows that samples with a lower proportion of α-methylstyrene in their structure have better dielectric characteristics compared with their counterparts with a high content of α-methylstyrene.
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Waware, Umesh Somaji, A. M. S. Hamouda, and Dipanwita Majumdar. "Synthesis, characterization and physicochemical studies of copolymers of aniline and 3-nitroaniline." Polymer Bulletin 77, no. 9 (October 9, 2019): 4469–88. http://dx.doi.org/10.1007/s00289-019-02957-y.
Повний текст джерелаАнотація:
Abstract Polyaniline (PA), the versatile conducting polymer, owing to its tunable optoelectronic properties, facile preparation methodology and reversible redox behavior, has elicited much interest among current researchers, particularly in the fields of energy generation storage devices, protective coatings and electrochemical sensors. However, its commercialization has been much restricted due to low solution processability and thermal stability. Recent studies reveal that the above-mentioned challenges can effectively be addressed by copolymerization of PA with suitable components. In addition, the properties of copolymers could be modified and tuned by varying the monomer ratios. Thus, the present work is concerned with the fabrication of poly(aniline-co-3-nitroaniline) with varying compositions obtained by in situ oxidative copolymerization of aniline and 3-nitroaniline by altering the molar ratio of monomers. Optimization of the physicochemical properties such as UV–visible absorption, solubility, thermal stability, electrical conductivity and dielectric signatures, particle size and morphology was achieved by varying the composition of monomeric substituents in these copolymers. Smoother morphology of the copolymer films was revealed by morphological studies via AFM technique and supported by particle size distribution study. The physicochemical trends demonstrated that proper proportions of nitro (–NO2) group in the polymer chain are essential to achieve desired optimal physicochemical properties. Therefore, copolymers are ideally appropriate for multifaceted applications and would promote wider usage of conjugated polymers in various fields of organic-based optoelectronic as well as energy storage devices in the near future.
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Bouaamlat, Hussam, Nasr Hadi, Najat Belghiti, Hayat Sadki, Mohammed Naciri Bennani, Farid Abdi, Taj-dine Lamcharfi, Mohammed Bouachrine, and Mustapha Abarkan. "Dielectric Properties, AC Conductivity, and Electric Modulus Analysis of Bulk Ethylcarbazole-Terphenyl." Advances in Materials Science and Engineering 2020 (January 30, 2020): 1–8. http://dx.doi.org/10.1155/2020/8689150.
Повний текст джерелаАнотація:
Electrical and dielectric properties for bulk ethylcarbazole-terphenyl (PEcbz-Ter) have been studied over frequency range 1 kHz–2 MHz and temperature range (R.T –120°C). The copolymer PEcbz-Ter was characterised by using X-ray diffraction. The frequency dependence of the dielectric constant (εr′) and dielectric loss (εr″) has been investigated using the complex permittivity. εr′ of the copolymer decreases with increasing frequency and increases with temperature. AC conductivity (σac) data were analysed by the universal power law. The behaviour of σac increases with increasing temperature and frequency. The change of the frequency exponent (s) with temperature was analysed in terms of different conduction mechanisms, and it was found that the correlated barrier-hopping model is the predominant conduction mechanism. The electric modulus was used to analyze the relaxation phenomenon in the material.
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Mälzer, Till, Lena Mathies, Tino Band, Robert Gorgas, and Hartmut S. Leipner. "Influence of Different Solvents and High-Electric-Field Cycling on Morphology and Ferroelectric Behavior of Poly(Vinylidene Fluoride-Hexafluoropropylene) Films." Materials 14, no. 14 (July 12, 2021): 3884. http://dx.doi.org/10.3390/ma14143884.
Повний текст джерелаАнотація:
P(VdF-HFP) films are fabricated via a solution casting doctor blade method using high (HVS) and low (LVS) volatile solvents, respectively. The structural properties and the ferroelectric behavior are investigated. The surface structure and crystal phase composition are found to be strongly dependent on the type of solvent. LVS leads to a rougher copolymer surface structure with large spherulites and a lower crystallinity in contrast with HVS. The crystalline phase of copolymer films fabricated with HVS consists almost exclusively of α-phase domains, whereas films from LVS solution show a large proportion of γ-phase domains, as concluded from Raman and X-ray diffraction spectra. Virgin films show no ferroelectric (FE) switching polarization at electric field amplitudes below 180 MV/m, independent of the solvent type, observed in bipolar dielectric displacement—electric field measurements. After applying electric fields of above 180 MV/m, a FE behavior emerges, which is significantly stronger for LVS films. In a repeated measurement, FE polarization switching already occurs at lower fields. A shielding effect may be related to this observation. Additionally, Raman bands of polar γ-phase increase by high-electric-field cycling for the LVS sample. The solvent used and the resulting crystal phase composition of the virgin sample is crucial for the copolymer behavior during bipolar electrical cycling.
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Chau, Ngoc Mai, Thi Thai Ha La, and Minh Tuan Sam. "Synthesis of chitosan-graft-polyaniline with the conductive potential." Vietnam Journal of Science and Technology 59, no. 6A (March 11, 2022): 12–22. http://dx.doi.org/10.15625/2525-2518/16215.
Повний текст джерелаАнотація:
Chitosan (CS) is one of the most plenteous polymers in nature and gets ubiquitous in many fields such as pharmaceutical and medical industries, wastewater treatment, agriculture, etc.due to its remarkable biodegradability and friendliness to human beings and ecology. Recently, nature-originated conductive materials havebeen gaining more attention than other materials because they can be utilized in reality, while others are difficultto decompose after use. Understandably, polyaniline (PANI), which is one of the prominent conductive polymers with a distinguished conjugated structure, simple synthesis, cost-effectiveness, environmental stability, and conductivity, was grafted with CS (CS-graft-PANI) to produce a copolymer possessing a combination of properties between CS and PANI. Althoughthere have been several researchesrelated to this copolymer, the grafting efficiency and electrical conductivity wererelatively low. Therefore, this paper aims at obtainingahigher efficiency and electrical conductivity of CS-graft-PANI copolymerby systematically adjusting the synthesis parameters including the volume of acid solution to dissolve aniline, initiator concentration, acetic acid concentration to dissolve CS, the initiator methods and dopants. As a result, the best copolymer product reached a graft efficiency of 69.4% and grafting percentage of 78.5% with an electrical conductivity of 7.9610-3 Scm-1. The chemical composition and morphology were determinedby Fourier-transform Infrared Spectroscopy and Scanning Electron Microscope while the thermal characteristic was also carefully detected via Thermogravimetric Analysis.
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Grytsenko, Oleksandr, Ivan Gajdoš, Emil Spišák, Volodymyr Krasinskyi, and Oleh Suberlyak. "Novel Ni/pHEMA-gr-PVP Composites Obtained by Polymerization with Simultaneous Metal Deposition: Structure and Properties." Materials 12, no. 12 (June 18, 2019): 1956. http://dx.doi.org/10.3390/ma12121956.
Повний текст джерелаАнотація:
The synthesis and study of metal-containing hydrogels, particularly those filled with nickel nanoparticles, is currently of interest to many researchers. This paper presents the results of an investigation of the structure and properties of Ni(0)-filled composites on the basis of 2-hydroxyethylmethacrylate copolymers (HEMA) with polyvinylpyrrolidone (PVP) and their hydrogels. The authors of the article are the first who propose the method to produce these materials by combining the processes of polymer matrix synthesis and a reduction of Ni2+ ions. Synthesis is carried out in one stage without complicated equipment and is technologically simple. It is determined by thermometric research that the temperature conditions required for the chemical reduction of Ni2+ are achieved due to the heat released during the exothermic reaction of HEMA polymerization in the presence of PVP. With the help of Fourier transform infrared analysis, and thermogravimetric and differential-thermal analysis, the formation of a crosslinked graft copolymer based on HEMA and PVP was confirmed, and its structural parameters, including the efficiency of PVP grafting, PVP content in the copolymer, and the molecular weight of the interstitial fragment of the polymer network, were investigated. The results obtained with scanning electron microscopy revealed that the size of the Ni(0) particles is about 500 nm. X-ray structural analysis of the composites obtained confirmed the existence of metal nickel particles. The strength, elastic, sorption, electrical, and magnetic properties of the obtained composites in the solid (dry) and elastic (swollen) physical states, depending on the composition of the copolymer and the content of the metal filler, have been investigated.
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Yang, Song Bo, Ming Hua Tang, Guo Yang Wang, Bo Jiang, and Hua Yu Xu. "Fabrication and Electrical Properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12 Bi-Layer Composite Ferroelectric Thin Films." Advanced Materials Research 320 (August 2011): 170–75. http://dx.doi.org/10.4028/www.scientific.net/amr.320.170.
Повний текст джерелаАнотація:
The microstructure and electrical properties of P(VDF-TrFE)/Bi3.5Nd0.5Ti3O12bi-layer composite ferroelectric thin films deposited on Pt/Ti/SiO2/Si using two successive spin coatings were investigated. It shows the pores in Bi3.5Nd0.5Ti3O12(BNT) films were effectively suppressed by the presence of P(VDF-TrFE) copolymer films by SEM. The ferroelectric, leakage and dielectric properties of the thin films with different thickness ratio of P(VDF-TrFE) and BNT thin films were measured. With increasing the thickness of P(VDF-TrFE), the remnant polarization, coercive electric field, leakage current density and dielectric constant of thin films were all decreased (except pure P(VDF-TrFE) thin film). Results indicate that the key electrical properties were improved effectively by a little loss of the remnant polarization, which infers potential application in the filed of ferroelectric memory.
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Jang, Hyo Jun, Choon-Sang Park, Eun Young Jung, Gyu Tae Bae, Bhum Jae Shin, and Heung-Sik Tae. "Synthesis and Properties of Thiophene and Aniline Copolymer Using Atmospheric Pressure Plasma Jets Copolymerization Technique." Polymers 12, no. 10 (September 28, 2020): 2225. http://dx.doi.org/10.3390/polym12102225.
Повний текст джерелаАнотація:
This paper investigates the properties of thiophene and aniline copolymer (TAC) films deposited by using atmospheric pressure plasma jets copolymerization technique relative to various blending ratios of aniline and thiophene monomer for synthesizing the donor–acceptor conjugated copolymers. Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy are utilized to measure the surface morphology, roughness and film thickness of TAC films. Structural and chemical properties of TAC films are investigated by Fourier transforms-infrared spectroscopy (FT-IR), time of flight secondary ion mass spectrometry, and X-ray photoelectron spectroscopy. FE-SEM images show that the film thickness and nanoparticles size of the TAC films increase with an addition thiophene monomer in the aniline monomer. FE-SEM, FT-IR results show that TAC films are successfully synthesized on glass substrates in all cases. The iodine doped TAC film on the Si substrate with interdigitated electrodes shows the lowest electrical resistance at blending condition of thiophene of 25%.
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ADELI, MOHSEN, REZA SEPAHVAND, ALI BAHARI, and BANDAR ASTINCHAP. "CARBON NANOTUBE-GRAFT-BLOCK COPOLYMERS CONTAINING SILVER NANOPARTICLES." International Journal of Nanoscience 08, no. 06 (December 2009): 533–41. http://dx.doi.org/10.1142/s0219581x09006365.
Повний текст джерелаАнотація:
Polycaprolactone-polylactide block copolymers (PCL-block-PLA) were grafted onto filled multi-wall carbon nanotubes (MWCNT) successfully. In this synthesis, MWCNTs were opened and functionalized, and then they were filled by silver nanoparticles. The filled MWCNT were used as macroinitiator for ring opening polymerization of ε-caprolactone and L-lactide. Then the end hydroxyl functional groups of MWCNT-graft-PCL or MWCNT-graft-PLA were used as initiator for ring opening polymerization of lactide and ε-caprolactone and MWCNT-graft-PCL-block-PLA or MWCNT-graft-PLA-block-PCL were obtained, respectively. Length of grafted copolymer chains onto the MWCNT was controlled using CNT/monomer ratio. Nanocomposites' properties depend on the length of polymer blocks strongly. Structure of nanocomposites was evaluated by TEM and spectroscopy methods.
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Wang, Yuan, Laipan Zhu, and Cuifeng Du. "Progress in Piezoelectric Nanogenerators Based on PVDF Composite Films." Micromachines 12, no. 11 (October 20, 2021): 1278. http://dx.doi.org/10.3390/mi12111278.
Повний текст джерелаАнотація:
In recent years, great progress has been made in the field of energy harvesting to satisfy increasing needs for portable, sustainable, and renewable energy. Among piezoelectric materials, poly(vinylidene fluoride) (PVDF) and its copolymers are the most promising materials for piezoelectric nanogenerators (PENGs) due to their unique electroactivity, high flexibility, good machinability, and long–term stability. So far, PVDF–based PENGs have made remarkable progress. In this paper, the effects of the existence of various nanofillers, including organic–inorganic lead halide perovskites, inorganic lead halide perovskites, perovskite–type oxides, semiconductor piezoelectric materials, two–dimensional layered materials, and ions, in PVDF and its copolymer structure on their piezoelectric response and energy–harvesting properties are reviewed. This review will enable researchers to understand the piezoelectric mechanisms of the PVDF–based composite–film PENGs, so as to effectively convert environmental mechanical stimulus into electrical energy, and finally realize self–powered sensors or high–performance power sources for electronic devices.
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Patel, Rakesh B., Umesh P. Tarpada, and Dipak K. Raval. "Study on copolymers synthesized from 2,3-epoxypropyl-3-(2-furyl) acrylate – styrene and their glass fiber reinforced composites." Journal of Polymer Engineering 33, no. 4 (July 1, 2013): 303–14. http://dx.doi.org/10.1515/polyeng-2013-0054.
Повний текст джерелаАнотація:
Abstract 3-(2-Furyl) acrylic acid (FAA) and 2,3-epoxypropyl-3-(2-furyl) acrylate (EPFA) were synthesized. EPFA was characterized by Fourier transform infrared spectroscopy (FTIR) and 1H nuclear magnetic resonance (1HNMR) spectroscopy. Copolymerization of prepared EPFA was carried out with styrene as the comonomer, by varying the mole ratio of EPFA:styrene at different reaction times, using benzoyl peroxide as an initiator at 80°C in toluene. FAA, EPFA and copolymers were characterized by FTIR and 1HNMR spectroscopy, as well as viscosity, gel permeation chromatography (GPC) and epoxy equivalent weight (EEW). Various thermal and kinetics parameters were determined and interpreted in light of the nature of the curing agent, by using two different curing systems, namely, chlorosulfonic acid (ClSO3H) at 120°C and maleic anhydride/triethanolamine (MAn/TEA) at 160°C. Mechanical and electrical properties, as well as chemical resistance of the selected glass fiber reinforced composites, were determined according to the ASTM method and discussed in light of copolymer composites.
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Zhang, Chen, Zhang, Du, and Zhao. "Design and Characterization of New D–A Type Electrochromic Conjugated Copolymers Based on Indolo[3,2-b]Carbazole, Isoindigo and Thiophene Units." Polymers 11, no. 10 (October 8, 2019): 1626. http://dx.doi.org/10.3390/polym11101626.
Повний текст джерелаАнотація:
Two new donor–acceptor (D–A) type organic conjugated random copolymers were successfully synthesized by three-component Stille coupling polymerization of indolo[3,2-b]carbazole (ICZ), isoindigo (IID) and thiophene units, namely PITID-X (X = 1 and 2), with the controlled monomer feed ratios of 3:1:4 and 1:1:2, respectively. The strategy of incorporating different alkyl-branched donor/acceptor units and raw material feed ratios facilitated the improvement of optical properties, solubility, conjugated structure, and electrochromic performance. Cyclic voltammetry, UV-vis-NIR absorption spectra, kinetic and colorimetric measurements of the spray-coated films were recorded in the fabricated three-electrode cells. The results showed that PITID-2, whose optical/electrical properties were better than that of PITID-1, was the candidate electrochromic material due to low band gap of 1.58 eV accompanying the color changing from cyan (neutral state) to gray (oxidized state). The copolymer also illustrated fast bleaching/coloration response time of 2.04/0.33 and 1.35/1.50 s in a 4 s time interval, high coloration efficiency of 171.52 and 153.08 cm2 C−1 and stable optical contrast of 18% and 58% at the wavelength of 675 and 1600 nm, respectively.
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Lu, Jiang Rong, Yu Feng Wang, Pu Xuan Yan, and Fei Xue Han. "Effects of MPBM on Crosslinking Density and Mechanical Properties of Tetrafluoroethylene-Propylene Copolymer." Advanced Materials Research 881-883 (January 2014): 897–900. http://dx.doi.org/10.4028/www.scientific.net/amr.881-883.897.
Повний текст джерелаАнотація:
The composites of tetrafluoroethylene-propylene copolymer (TFE-P copolymer)/N, N'-metaphenylene-bis-maleimide (MPBM)/DCP were prepared by mill. The effects of MPBM on the crosslinking density and mechanical properties of TFE-P copolymer were investigated by equilibrium swelling method, MDR rheometer and electric tensile testing machine. The results show that MPBM can efficiently increase the crosslinking density of TFE-P copolymer cured with peroxide. There is a linear relationship between MPBM and the crosslinking density while MPBM is less than 5 phr.; due to the resinification and reinforcing effect of micro-zone of MPBM resin, the crosslinking degree and the modulus of the composite increase faster while MPBM is used more than 5 phr. Perfect network and mechanical properties could be obtained by regulating the amount of MPBM in peroxide curing system.
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Mahudeswaran, A., A. Jeeva, J. Chandrasekaran, and P. S. Vijayanand. "Structural and electrical properties of new core-shell silver poly(m-toluidine-co-2-bromoaniline) nanocomposites." Materials Science-Poland 37, no. 4 (December 1, 2019): 526–34. http://dx.doi.org/10.2478/msp-2019-0064.
Повний текст джерелаАнотація:
AbstractIn this article, we report the synthesis and characterization of silver dispersed poly(m-toluidine-co-2-bromoaniline) copolymer synthesized by chemical oxidative polymerization method. The synthesized copolymer composites were subjected to different analytical characterization methods, such as FT-IR, UV, XRD, SEM, photoluminescence and electrical conductivity studies. All the polymer samples are found to be soluble in common organic solvents. UV absorption spectra show a red shift when silver nanoparticles are dispersed in the copolymer. The characteristic peaks observed in FT-IR spectra confirm the formation of the copolymer. XRD pattern reveals the crystalline nature of the copolymer composites and sharp peaks in the spectra confirm the presence of silver particles. The silver nanoparticles change the surface morphology in the form of perfect encapsulation. The electrical conductivity of the polymer composites is found to vary from 10−4 S/cm to 10−6 S/cm. PL study reveals the charge transfer between the copolymer and the silver particles.
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Prozorova, G. F., A. I. Emel’yanov, and S. A. Korzhova. "New functional copolymers of 1-vinyl-1,2,4-triazole with allylamine." Proceedings of Universities. Applied Chemistry and Biotechnology 10, no. 3 (October 8, 2020): 536–40. http://dx.doi.org/10.21285/2227-2925-2020-10-3-536-540.
Повний текст джерелаАнотація:
New water-soluble functional copolymers based on 1-vinyl-1,2,4-triazole and allylamine were synthesized under the action of free-radical initiation conditions and azobisisobutyric acid dinitrile. Сopolymers of various compositions with a molecular weight of 1287–30204 Da were obtained by varying reaction conditions. The structure, molecular weight and physicochemical properties of the copolymers were determined using elemental analysis, IR and NMR 1H-spectroscopy, gel permeation chromatography, potentiometric and turbidimetric titration, as well as dynamic light scattering and thermogravimetric analysis. It was established that the obtained copolymers, exhibiting the properties of high-resistance organic semiconductors, are characterized by a specific electrical conductivity of 10-13 – 10-14 S/cm and high resistance to thermal destruction (up to 260–280 °C). These copolymers are promising as stabilizing polymer matrices in the formation of biologically active water-soluble hybrid organic-inorganic nanocomposites.
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Staneva, Desislava, Silvia Angelova, and Ivo Grabchev. "Spectral Characteristics and Sensor Ability of a New 1,8-Naphthalimide and Its Copolymer with Styrene." Sensors 20, no. 12 (June 21, 2020): 3501. http://dx.doi.org/10.3390/s20123501.
Повний текст джерелаАнотація:
In this study, a novel 6-(allylamino)-2-(2-(dimethylamino)ethyl)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NI3) was synthesized and characterized. Its copolymer with styrene was also obtained. The photophysical characteristics of NI3 were investigated in organic solvents and the results were compared with those of its structural analogue, 2-allyl-6-((2-(dimethylamino)ethyl)amino)-1H-benzo[de]isoquinoline-1,3(2H)-dione (NI4). The influences of the pH in the medium and different metal ions on the fluorescent intensity of monomers and polymers were also investigated. Computational tools (DFT and TDDFT calculations) were employed when studying the structure and properties of the 1,8-naphthalimide-based chromophores. Although the position of the N,N-dimethylaminoethylamine receptor fragment did not significantly impact proton detection, it was still important for detecting metal ion sensor ability, especially for monomeric 1,8-naphthalimide structures and their copolymers with styrene.
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Hamid, Y., and P. Svoboda. "A Study on Thermal and Electrical Conductivities of Ethylene-Butene Copolymer Composites with Carbon Fibers." International Polymer Processing 36, no. 4 (September 1, 2021): 417–22. http://dx.doi.org/10.1515/ipp-2020-4003.
Повний текст джерелаАнотація:
Abstract Ethylene-butene copolymer (EBC)/carbon-fiber (CF) composites can be utilized as an electromechanical material due to their ability to change electric resistance with mechanical strain. The electro-mechanical properties and thermal conductivity of ethylene butene copolymer (EBC) composites with carbon fibers were studied. Carbon fibers were introduced to EBC with various concentrations (5 to 25 wt%). The results showed that carbon fibers’ addition to EBC improves the electric conductivity up to 10 times. Increasing the load up to 2.9 MPa will raise the electric resistance change by 4 500% for a 25% fiber sample. It is also noted that the EBC/CF composites’ electric resistance underwent a dramatic increase in raising the strain. For example, the resistance change was around 13 times higher at 15% strain compared to 5% strain. The thermal conductivity tests showed that the addition of carbon fibers increases the thermal conductivity by 40%, from 0.19 to 0.27 Wm–1K–1.
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Slobodian, Petr, Pavel Riha, Robert Olejnik, and Michal Sedlacik. "Ethylene-Octene-Copolymer with Embedded Carbon and Organic Conductive Nanostructures for Thermoelectric Applications." Polymers 12, no. 6 (June 9, 2020): 1316. http://dx.doi.org/10.3390/polym12061316.
Повний текст джерелаАнотація:
Hybrid thermoelectric composites consisting of organic ethylene-octene-copolymer matrices (EOC) and embedded inorganic pristine and functionalized multiwalled carbon nanotubes, carbon nanofibers or organic polyaniline and polypyrrole particles were used to form conductive nanostructures with thermoelectric properties, which at the same time had sufficient strength, elasticity, and stability. Oxygen doping of carbon nanotubes increased the concentration of carboxyl and C–O functional groups on the nanotube surfaces and enhanced the thermoelectric power of the respective composites by up to 150%. A thermocouple assembled from EOC composites generated electric current by heat supplied with a mere short touch of the finger. A practical application of this thermocouple was provided by a self-powered vapor sensor, for operation of which an electric current in the range of microvolts sufficed, and was readily induced by (waste) heat. The heat-induced energy ensured the functioning of this novel sensor device, which converted chemical signals elicited by the presence of heptane vapors to the electrical domain through the resistance changes of the comprising EOC composites.
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Grytsenko, O. M., O. V. Suberlyak, B. V. Berezhnyy, and P. P. Voloshkevych. "Investigation of the properties of nickel-filled copolymers of polyvinylpyrrolidone and hydrogel materials based on them." Chemistry, Technology and Application of Substances 4, no. 1 (June 1, 2021): 213–18. http://dx.doi.org/10.23939/ctas2021.01.213.
Повний текст джерелаАнотація:
The properties of nickel-filled copolymers of polyvinylpyrrolidone with 2-hydroxyethylmethacrylate and hydrogel materials based on them, obtained by the method of polymerization with simultaneous reduction of metal ions have been investigated. The influence of polymer-monomer composition formulation, content of metal-filler and conditions of Ni2+ reduction reaction on physico-mechanical, sorption, electrical and magnetic characteristics of obtained materials has been established. It has been found that Ni(0) particles in the composites’ structure on the basis of polyvinylpyrrolidone with 2-hydroxyethylmethacrylate copolymers demonstrate catalytic activity, particularly, in the hydrolysis process of sodium borohydride.