Articles de revues : « Copolymer/oligomers »

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Shibata, Mitsuhiro, Ryutoku Yosomiya, Junzuo Wang, Chunhai Chen, Guohong Bai, Zhongwen Wu, Shanger Wang et Zhishen Mo. « Synthesis and Properties of Block Copolymers of Poly(ether sulphone)s with Liquid Crystalline Polyester Units ». Engineering Plastics 5, n^o 1 (janvier 1997) : 147823919700500. http://dx.doi.org/10.1177/147823919700500101.

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Block copolymers of poly(ethersulphone) (PES) oligomers with liquid crystalline polyester units were synthesized by the reaction of dihydroxy-terminated poly(ether sulphone) oligomers (number-average molecular weights: 704, 1,158 and 2570) and terephthaloyl bis(4-oxybenzoyl chloride), and their properties were investigated. The results indicated that the copolymer with PES segments of molecular weight of 704 possessed birefringent features when annealed at 360°C, while the copolymer with PES segments of molecular weight of 2,570 became isotropic. Also, the block copolymers had a better chemical resistance and high-temperature stability than PES.

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Shibata, Mitsuhiro, Ryutoku Yosomiya, Junzuo Wang, Chunhai Chen, Guohong Bai, Zhongwen Wu, Shanger Wang et Zhishen Mo. « Synthesis and Properties of Block Copolymers of Poly(ether sulphone)s with Liquid Crystalline Polyester Units ». Polymers and Polymer Composites 5, n^o 1 (janvier 1997) : 1–5. http://dx.doi.org/10.1177/096739119700500101.

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Block copolymers of poly(ethersulphone) (PES) oligomers with liquid crystalline polyester units were synthesized by the reaction of dihydroxy-terminated poly(ether sulphone) oligomers (number-average molecular weights: 704, 1,158 and 2570) and terephthaloyl bis(4-oxybenzoyl chloride), and their properties were investigated. The results indicated that the copolymer with PES segments of molecular weight of 704 possessed birefringent features when annealed at 360°C, while the copolymer with PES segments of molecular weight of 2,570 became isotropic. Also, the block copolymers had a better chemical resistance and high-temperature stability than PES.

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Polenz, I., A. Laue, T. Uhrin, T. Rüffer, H. Lang, F. G. Schmidt et S. Spange. « Thermally cleavable imine base/isocyanate adducts and oligomers suitable as initiators for radical homo- and copolymerization ». Polym. Chem. 5, n^o 23 (2014) : 6678–86. http://dx.doi.org/10.1039/c4py01002g.

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Shibata, Mitsuhiro, Masaya Katoh, Hayato Takase et Ayaka Shibita. « Stereocomplex formation in stereoblock copolymer networks composed of 4-armed star-shaped lactide oligomers and a 2-armed ε-caprolactone oligomer ». Polymer Chemistry 6, n^o 22 (2015) : 4123–32. http://dx.doi.org/10.1039/c5py00401b.

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Kuhnt, Tobias, Ramiro Marroquín García, Sandra Camarero-Espinosa, Aylvin Dias, A. Tessa ten Cate, Clemens A. van Blitterswijk, Lorenzo Moroni et Matthew B. Baker. « Poly(caprolactone-co-trimethylenecarbonate) urethane acrylate resins for digital light processing of bioresorbable tissue engineering implants ». Biomaterials Science 7, n^o 12 (2019) : 4984–89. http://dx.doi.org/10.1039/c9bm01042d.

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Gaborieau, Marianne, Tim J. Causon, Yohann Guillaneuf, Emily F. Hilder et Patrice Castignolles. « Molecular Weight and Tacticity of Oligoacrylates by Capillary Electrophoresis - Mass Spectrometry ». Australian Journal of Chemistry 63, n^o 8 (2010) : 1219. http://dx.doi.org/10.1071/ch10088.

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Oligo(acrylic acid) efficiently stabilizes polymeric particles, especially particles produced by reversible addition–fragmentation chain transfer (RAFT) (as hydrophilic block of an amphiphilic copolymer). Capillary electrophoresis (CE) has a far higher resolution power to separate these oligomers than the commonly used size exclusion chromatography. Coupling CE to electrospray ionization mass spectrometric detection unravels the separation mechanism. CE separates these oligomers, not only according to their degree of polymerization, but also according to their tacticity, in agreement with NMR analysis. Such analysis will provide insight into the role of these oligomers as stabilizers in emulsion polymerization, and into the mechanism of the RAFT polymerization with respect to degree of polymerization and tacticity.

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Kubicova, Marie, Elise Puchta, Sebastian Säger, Constanze Hug, Sandra Hofmann et Thomas J. Simat. « Styrene-acrylonitrile-copolymer and acrylonitrile-butadiene-styrene-copolymer : a study on extractable and migratable oligomers ». Food Additives & ; Contaminants : Part A 39, n^o 2 (15 novembre 2021) : 397–414. http://dx.doi.org/10.1080/19440049.2021.1995631.

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DONG, L. M., G. X. LIAO, C. LIU, S. S. YANG et X. G. JIAN. « SYNTHESIS AND CHARACTERIZATION OF POLY(PHTHALAZINONE ETHER NITRILE) COPOLYMERS WITH HYDROPHOBIC SURFACE ». Surface Review and Letters 15, n^o 05 (octobre 2008) : 705–9. http://dx.doi.org/10.1142/s0218625x08011731.

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Poly(phthalazinone ether nitrile) (PPEN) block copolymers containing polysiloxane were prepared so as to create a strongly hydrophobic polymer surface. The copolymers were synthesized from eugenol end-capped polydimethylsiloxane (PDMS) and fluoro-terminated PPEN oligomers by the aromatic nucleophilic substitution polycondensation in the presence of dimethyl sulfoxide/o-dichlorobenzene and K 2 CO 3 as solvents and catalyst, respectively. The resultant copolymers were characterized by FTIR, 1 H NMR, and gel permeation chromatography. XPS analysis results indicated that the copolymer film had a very rich PDMS segment surface. Atomic force microscopy further showed that there existed a continuous PDMS phase on the copolymer surface and PPEN as the dispersive particles was dispersed at diameters between 0.1 and 0.3 nm. The enrichment of PDMS in the copolymer surface could be responsible for an increase of surface water repellency (113.4°).

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Gao, Xin, Lei Deng, Jianfeng Hu et Hao Zhang. « Ferrocene-Containing Conjugated Oligomers Synthesized by Acyclic Diene Metathesis Polymerization ». Polymers 11, n^o 8 (12 août 2019) : 1334. http://dx.doi.org/10.3390/polym11081334.

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A series of conjugated, symmetrical, and ferrocene-containing main-chain monomers was prepared following a gentle coupling reaction. Ferrocene-containing oligomers with all-trans-configured vinylene bonds could be synthesized via acyclic diene metathesis (ADMET) polymerization. These oligomers had a larger Stokes shift (2400 to 2600 cm−1) and both exhibited stable and reversible electrochemistry. Meanwhile, the copolymerization of 1,1’-bis[1-methyl-2-(4-vinylphenyl)ethenyl]ferrocene with 2,7-divinyl-9,9-dioctylfluorene was achieved. The structurally regular copolymers proved their optical and electrochemical properties. The fluorescence intensity of the copolymer gradually enhanced with the increasing number of fluorene units. At the same time, it was also found that the color of the copolymers had a significant change from yellow-green to red.

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Satoh, Kotaro, et Masami Kamigaito. « Sequence-Controlled Vinyl Polymers by Transition Metal-Catalyzed Step-Growth and Living Radical Polymerizations ». MRS Proceedings 1613 (2014) : 17–21. http://dx.doi.org/10.1557/opl.2014.153.

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ABSTRACTThe metal-catalyzed step-growth radical polymerization was achieved to enable two systems for preparing tailored polymeric structures, i.e., sequence-regulated vinyl copolymer and periodically-functionalized polymer. The former is a novel strategy for preparing sequence-regulated vinyl copolymers by step-polymerization of sequence-regulated vinyl oligomers prepared from common vinyl monomers as building blocks. The later deals the simultaneous chain- and step-growth radical polymerization, which resulted in the polymers with periodic functional groups.

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Theis, Julia, et Helmut Ritter. « Formation of epoxide-amine oligo-adducts as OH-functionalized initiators for the ring-opening polymerization of ε-caprolactone ». Beilstein Journal of Organic Chemistry 6 (1 octobre 2010) : 938–44. http://dx.doi.org/10.3762/bjoc.6.105.

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Epoxide-amine oligo-adducts were synthesized via a one-pot microwave assisted heterogeneous catalytic transfer hydrogenation. Accordingly, 4-nitroanisole was reduced under microwave conditions to give 4-aminoanisole which reacted immediately with the diglycidyl ether of bisphenol A in an addition polymerization reaction to yield oligo(amino alcohol)s. The hydroxy groups of the new formed oligomers were used as the initiator for the ring-opening polymerization of ε-caprolactone to produce a graft copolymer.

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Cerda, Blas A., David M. Horn, Kathrin Breuker et Fred W. McLafferty. « Sequencing of Specific Copolymer Oligomers by Electron-Capture-Dissociation Mass Spectrometry ». Journal of the American Chemical Society 124, n^o 31 (août 2002) : 9287–91. http://dx.doi.org/10.1021/ja0123756.

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Okada, Kenji, Masanari Takano, Yasuaki Tokudome, Yomei Tokuda et Masahide Takahashi. « Preparation of Silicophosphate Alternating Hybrid Copolymers via Nonaqueous Acid-Base Reactions of Phosphoric Acid and Organo-Bridged Bis(chlorosilane) ». Molecules 25, n^o 1 (28 décembre 2019) : 127. http://dx.doi.org/10.3390/molecules25010127.

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A design of atomic and oligomer level structure in organic-inorganic hybrid materials is highly important for various applications. Nonaqueous acid-base reaction allows us to prepare silicophosphates with controlled inorganic networks (–(O–P–O–Si)n) at atomic level because phosphorous and silicon-based precursors can react directly, resulting in an alternating copolymer network. Organic functionalization in those materials has been realized so far by using organic-modified phosphorous acid and/or organo-chlorosilane as precursors. In the present study, silicophosphate oligomers exhibiting inorganic-organic hybrid chains of (–(O–P–O–Si–R–Si)n) (R: bridging organic functional groups), are prepared from phosphoric acid and organo-bridged bis(chlorosilane). The 1, 2-bis(chlorodimethylsilyl)ethane ((C2H4)(Me2SiCl)2) and 1, 4-bis(chlorodimethylsilyl)benzene ((C6H4)(Me2SiCl)2) were used as organo-bridged bis(chlorosilane). Different types of silicophosphate oligomers with different network structures and terminal groups (P-OH and/or Si-Cl) were prepared by changing the reaction temperature and molar ratio of precursors. The formation of low molecular weight oligomers of ring and cage morphologies (ring tetramer, cage pentamer, and ring hexamer) is suggested in the product prepared from phosphoric acid and (C6H4)(Me2SiCl)2 molecule at 150 °C. Those silicophosphate hybrid oligomers are expected to be used as building blocks of hybrid materials with well-defined network structures for desired functionalities.

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Mina, Erene W., Cristian Lasagna-Reeves, Charles G. Glabe et Rakez Kayed. « Poloxamer 188 Copolymer Membrane Sealant Rescues Toxicity of Amyloid Oligomers In Vitro ». Journal of Molecular Biology 391, n^o 3 (août 2009) : 577–85. http://dx.doi.org/10.1016/j.jmb.2009.06.024.

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Hu, Wei, Lei Wang, Quanyong Wang, Anbo Luan, Yuliang Mai, Linjia Huang, Yongjun Chen, Shijing Yan et Wenjie Xiong. « Polypropylene Glycol-Polyoxytetramethylene Glycol Multiblock Copolymers with High Molecular Weight : Synthesis, Characterization, and Silanization ». Molecules 24, n^o 23 (26 novembre 2019) : 4317. http://dx.doi.org/10.3390/molecules24234317.

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The high crystallization at room temperature and high cost of polyoxytetramethylene glycol (PTMG) have become obstacles to its application. To overcome these problems, a segment of PTMG can be incorporated into a block copolymer. In this work, polypropylene (PPO) glycol-polyoxytetramethylene (PPO-PTMG) multiblock copolymers were designed and synthesized through a chain extension between hydroxyl (OH)-terminated PPO and PTMG oligomers. The chain extenders, feed ratios of the catalyst/chain extender/OH groups, reaction temperature, and time were optimized several times to obtain a PPO-PTMG with low crystallization and high molecular weight. Multiblock copolymers with low crystallization and high average molecular weight (Mn = 1.0–1.4 × 104 Dalton) were harvested using m-phthaloyl chloride as the chain extender. The OH-terminated PPO-PTMG multiblock copolymer with high Mn and a functionality near two was further siliconized by 3-isocyanatopropyltrimethoxysilane to synthesize a novel silyl-terminated polyether. This polyether has an appropriate vulcanizing property and potential applications in sealants/adhesive fields.

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Journo-Gershfeld, Gal, Dana Kapp, Yosi Shamay, Jindřich Kopeček et Ayelet David. « Hyaluronan Oligomers-HPMA Copolymer Conjugates for Targeting Paclitaxel to CD44-Overexpressing Ovarian Carcinoma ». Pharmaceutical Research 29, n^o 4 (16 février 2012) : 1121–33. http://dx.doi.org/10.1007/s11095-012-0672-1.

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Bairamov, M. R., Sh J. Guliyeva, G. M. Mehdiyeva et M. A. Agayeva. « PURIFICATION OF WATER SYSTEMS FROM URANIUM SALTS USING ACRYLONITRILE-STRUCTURED TRIPLE CO-OLIGOMERS OF 4-ISOPROPENIL-PHENOL, FORMALDEHYDE AND 4-(1-METHYL)-1-DIMETOXSI-PHOSPHORYLETHYL)PHENOL ». Azerbaijan Chemical Journal, n^o 1 (28 mars 2023) : 155–61. http://dx.doi.org/10.32737/0005-2531-2023-1-155-161.

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The article presents the results of three-component condensation of 4-isopropenylphenol, formaldehyde and 4-(1-methyl)-1-dimethoxsiphosphorylethyl)phenol cooligomers, their structuring with acrylonitrile. In order to include the carboxyl group in the structure of the cross-linked copolymer, hydrolysis was carried out in the presence of an aqueous solution of potassium hydroxide. The process of sorption of uranyl ions from model aqueous systems by structured (crosslinked) with acrylonitrile and their product of hydrolyze. The structure of the cross-linked copolymer was confirmed by IR spectroscopy data. It has been established that the process of sorption of uranyl ions is significantly affected by the pH of the medium. The best results in the extraction of uranyl ions by the sorbent are achieved at pH 7–8 (at room temperature, the degree of their sorption is ~89–93%, and SCS is ~229–239 mg/g). It has been established that the process is completed within 24 hours, cross-linked co-oligomers can be reused after desorption of uranyl ions by mineral acids

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Bayramov, M. R., G. M. Mekhtieva, Dzh A. Nagiev, Sh Dzh Gulieva, M. A. Agaeva et A. M. Magerramov. « Acrylonitrile-Structured Ternary Co-oligomers of 4-Isopropenylphenol, Phenol, and Formaldehyde as Sorbents for Recovery of Uranyl Ions from Aqueous Systems ». Журнал прикладной химии, n^o 4 (15 décembre 2023) : 382–90. http://dx.doi.org/10.31857/s0044461823040084.

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Triple co-oligomers of 4-isopropenylphenol, phenol and formaldehyde were synthesized and used for the first time as precursors in the structuring reaction in the presence of acrylonitrile and the initiator benzoyl peroxide. The yield of cross-linked copolymers is 84% (of theory). The use of hydrolyzed cross-linked copolymers is shown to be effective as sorbents for the extraction of UO22+ ions from model aqueous systems under batch conditions, and the degree of their sorption significantly depends on the medium pH, the initial concentration of UO22+ ions and the exposure time. The best results were achieved at pH 7 and 9, at which the degree of extraction of UO22+ ions from an aqueous solution with their initial concentration of 134 ± 0.5 mg L–1 is ~93.5% (room temperature, 24 h), while the sorption capacity of the cross-linked copolymer is ~210 mg g–1. The highest sorption capacity of the copolymer reaches 300 ± 30 mg g–1. The possibility of regeneration of the sorbent with mineral acid (НNO3, HCl) was revealed; the maximum degree of desorption of UO22+ ions is ~91%.

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Fang, Pengtao, Xingmei Lu, Qing Zhou, Dongxia Yan, Jiayu Xin, Junli Xu, Chunyan Shi, Yongquan Zhou et Shuqian Xia. « Controlled alcoholysis of PET to obtain oligomers for the preparation of PET-PLA copolymer ». Chemical Engineering Journal 451 (janvier 2023) : 138988. http://dx.doi.org/10.1016/j.cej.2022.138988.

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Yang, Shu-Chian, Chun-Yu Chen, Hung-Yu Wan, Szu-Ying Huang et Ta-I. Yang. « Electroactive Composites with Block Copolymer-Templated Iron Oxide Nanoparticles for Magnetic Hyperthermia Application ». Polymers 11, n^o 9 (31 août 2019) : 1430. http://dx.doi.org/10.3390/polym11091430.

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Cancer has been one of the leading causes of human death for centuries. Magnetic hyperthermia is a promising technique to confine and control cancers. However, particles used in magnetic hyperthermia leaking from where the cancers are located could compromise human health. Therefore, we developed electroactive iron oxide/block copolymer composites to tackle the leakage problem. Experimental results show that oleylamine-modified magnetic iron oxide (Fe3O4) particles and electroactive tetraaniline (TA) could be templated in the self-assembled microstructures of sulfonated [styrene-b-(ethylene-ran-butylene)-b-styrene] (S-SEBS) block copolymers. Various amounts of Fe3O4 particles and TA oligomer were incorporated in S-SEBS block copolymer and their electroactive behavior was confirmed by exhibiting two pairs of well-defined anodic and cathodic current peaks in cyclic voltammetry tests. The heating performance of the resultant TA/Fe3O4/polymer composites improved on increasing the added amount of Fe3O4 particles and TA oligomers. Both Fe3O4 and TA can contribute to improved heating performance, but Fe3O4 possesses a greater contribution than TA does. Hence, the main source for increasing the composites’ temperature is Neel relaxation loss from Fe3O4 magnetic particles.

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Duflot, V. R., A. V. Gaivoronsky et E. I. Lobanova. « Synthesis of thermosensitive copolymers of N-isopropylacrylamide with 2-aminoethylmethacrylate hydrochloride ». Fine Chemical Technologies 16, n^o 2 (25 mai 2021) : 167–75. http://dx.doi.org/10.32362/2410-6593-2021-16-2-167-175.

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Objectives. Due to the increasing number of oncological diseases, active research into developing new radiopharmaceuticals is underway. Thermosensitive copolymers have valuable physicochemical properties that can be harnessed to develop therapeutic radiopharmaceuticals for treating solid tumors. The aim of this study was to develop a method for producing thermosensitive copolymers that can find use as radionuclide carriers to create therapeutic radiopharmaceuticals for treating solid tumors.Methods. Using radical copolymerization in polar solvents, we synthesized water-soluble copolymers based on N-isopropyl acrylamide and 2-aminoethyl methacrylate hydrochloride. The resulting copolymers were characterized in terms of molecular composition and hydrodynamic properties using gel permeation chromatography, IR spectroscopy, potentiometry, and viscometry. Changes in optical density during temperature scanning helped determine the phase transition temperature (PTT) of aqueous copolymer solutions.Results. We developed a method for preparing copolymers of N-isopropylacrylamide with 2-aminoethyl methacrylate using radical copolymerization in water and isopropanol with a content of 2-aminoethyl methacrylate hydrochloride in a copolymer up to 23 mol %. We studied how the second comonomer affected the PTT of the aqueous copolymer solutions. An increase in the content of 2-aminoethyl methacrylate in the copolymer caused the PTT to increase. We found that the change in the PTT depending on the content of 2-aminoethyl methacrylate units in the copolymer had a straightforward relationship with its content up to 17 mol %. The use of physiological saline as a solvent led to a temperature decrease of the phase transition by two degrees.Conclusions. The method of producing thermosensitive copolymers by radical copolymerization in isopropanol does not allow creating a radionuclide carrier. Solutions of the obtained lowmolecular weight oligomers form coacervate solutions, which will inevitably cause the radionuclide to spread throughout the body. The copolymers obtained by radical copolymerization in water with the content of the second comonomer 2-aminoethyl methacrylate from 10–17 mol % can be used as a radionuclides carrier provided that a physiological solution of sodium chloride is used as a solvent.

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Liu, Jiawei, Guo Du, Hongda Yu, Xueyin Zhang et Tiehong Chen. « Synthesis of Hierarchically Porous Bioactive Glass and Its Mineralization Activity ». Molecules 28, n^o 5 (27 février 2023) : 2224. http://dx.doi.org/10.3390/molecules28052224.

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Mesoporous bioactive glass is a promising biomaterial for bone tissue engineering due to its good biocompatibility and bioactivity. In this work, we synthesized a hierarchically porous bioactive glass (HPBG) using polyelectrolyte-surfactant mesomorphous complex as template. Through the interaction with silicate oligomers, calcium and phosphorus sources were successfully introduced into the synthesis of hierarchically porous silica, and HPBG with ordered mesoporous and nanoporous structures was obtained. The morphology, pore structure and particle size of HPBG can be controlled by adding block copolymer as co-template or adjusting the synthesis parameters. The ability to induce hydroxyapatite deposition in simulated body fluids (SBF) demonstrated the good in vitro bioactivity of HPBG. Overall, this work provides a general method for the synthesis of hierarchically porous bioactive glasses.

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Lim, Byung-Ho, Soo-Han Kwon, En-Chang Kang, Heon Park, Hyun-Woo Lee et Whan-Gi Kim. « Isolation and identification of cyclic oligomers of the poly(ethylene terephthalate)-poly(ethylene isophthalate) copolymer ». Journal of Polymer Science Part A : Polymer Chemistry 41, n^o 7 (13 février 2003) : 881–89. http://dx.doi.org/10.1002/pola.10637.

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Todea, Anamaria, Emese Biro, Valentin Badea, Cristina Paul, Adinela Cimporescu, Lajos Nagy, Sándor Kéki, Geza Bandur, Carmen Boeriu et Francisc Péter. « Optimization of enzymatic ring-opening copolymerizations involving δ-gluconolactone as monomer by experimental design ». Pure and Applied Chemistry 86, n^o 11 (1 novembre 2014) : 1781–92. http://dx.doi.org/10.1515/pac-2014-0717.

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Abstract Enzymatic incorporation of carbohydrate-derived monomer units into hydrophobic polyester backbones represents a promising alternative to obtain new biodegradable oligomers and polymers. Immobilized lipases are efficient biocatalysts for copolymerization of β-butyrolactone and δ-gluconolactone, but only a systematic optimization study was able to highlight the influence of the main reaction parameters on the polymerization degree and on the relative copolymer content of the product. Therefore, experimental design was employed for determination of the optimal ring-opening copolymerization conditions in solventless reaction systems, at temperatures up to 80 °C. The obtained products, cyclic and linear polyesters, have been characterized by FT-IR, MALDI-TOF MS, NMR, and TG analysis, demonstrating the incorporation of gluconolactone unit(s) into the hydrophobic backbone of the polyester and the formation of new bio-based products.

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Schulten, Hans-Rolf, Bernd Plage et Robert P. Lattimer. « Pyrolysis-Field Ionization Mass Spectrometry of Rubber Vulcanizates ». Rubber Chemistry and Technology 62, n^o 4 (1 septembre 1989) : 698–708. http://dx.doi.org/10.5254/1.3536269.

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Abstract Time-/temperature-resolved Py-FIMS allows for the identification of rubber components in compounds containing normal organic additives. Signals due to polymer pyrolyzates, which may be masked by processing oil in nontemperature resolved spectra, are easily obtained. Py-FI spectra from cured BR and NR differ from the corresponding uncured samples in that signals from sulfur-containing oligomers are observed. For SBR, the signals from sulfur-containing pyrolyzates were not distinguishable in the complex mixture of hydrocarbon fragments that was produced. Therefore, unambiguous distinction between cured and uncured SBR was difficult. Since Py-FI mass spectra for rubber blends appear similar to the sum of the corresponding single component spectra, secondary reactions of chain fragments from the two blend components are minimal. These results are consistent with Curie-point Py-MS studies which also showed little interaction between components in blends. Since the Py-FI mass spectrum of the styrene-butadiene block copolymer is similar to the sum of single component spectra, it is obvious that styrene-butadiene sequences are not very abundant. In contrast, mixed oligomers containing both styrene and butadiene units are found for SBR copolymers. The absence of styrene dimer and trimer, as well as high-mass oligomers of butadiene, indicates that the amount of block styrene is very low. Furthermore, the large numbers of mixed oligomers indicates a random sequence distribution. In summary, Py-FIMS is a very effective technique for direct rubber compound analysis. The sample can be examined directly, without pretreatment, and both organic additives and the rubber components can be identified in the same experiment. With programmed heating of the rubber, one can obtain separate (time-/temperature-resolved) FI mass spectra for the organic additives and the rubber pyrolyzates. The results are interesting in that much higher mass oligomers can be observed by Py-FIMS than are detected by other methods of Py-MS. For example, while the low voltage Py-EIMS typically shows no higher oligomers than trimer or tetramer for diene rubbers, Py-FIMS shows sequences containing perhaps 15–20 monomer units. This improved performance is due mainly to (a) the close proximity of the pyrolysis chamber to the field emitter (which minimizes secondary reactions) and (b) the very soft ionization provided by the FI technique. In favorable cases, Py-FIMS can be used to study long sequences in homopolymers, copolymers, and blends. As we have noted, pendent groups (e.g., mercaptobenzothiazyl) and crosslinks may be detected among the pyrolysis products. While some rubbers (e.g., polyisoprene) thermally degrade to give high abundances of oligomers, others degrade in a more random fashion (e.g., SBR) to give very complex mixtures of pyrolyzates. Polystyrene is an interesting case in which thermal degradation by retropolymerization (unzipping) is so prevalent that the monomer is by far the dominant pyrolyzate, and long oligomeric sequences are precluded. Thus, while Py-FIMS can easily be used for qualitative identification of rubber components, more detailed information may or may not be discernible in analysis of a particular rubber sample.

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Sato, Masahiro, Akiko Kumada et Kunihiko Hidaka. « First-principles studies of carrier injection in polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) oligomers ». IEEE Transactions on Dielectrics and Electrical Insulation 24, n^o 1 (février 2017) : 574–82. http://dx.doi.org/10.1109/tdei.2016.006346.

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Saint-Loup, René, Jean-Jacques Robin et Bernard Boutevin. « Synthesis of Poly(ethylene terephthalate)-block-Poly(tetramethylene oxide) Copolymer by Direct Polyesterification of Reactive Oligomers ». Macromolecular Chemistry and Physics 204, n^o 7 (mai 2003) : 970–82. http://dx.doi.org/10.1002/macp.200390072.

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Prasad, Saradh, Mamduh J. Aljaafreh, Mohamad S. AlSalhi et Abeer Alshammari. « Encapsulated Passivation of Perovskite Quantum Dot (CsPbBr3) Using a Hot-Melt Adhesive (EVA-TPR) for Enhanced Optical Stability and Efficiency ». Crystals 11, n^o 4 (13 avril 2021) : 419. http://dx.doi.org/10.3390/cryst11040419.

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The notable photophysical characteristics of perovskite quantum dots (PQDs) (CsPbBr3) are suitable for optoelectronic devices. However, the performance of PQDs is unstable because of their surface defects. One way to address the instability is to passivate PQDs using different organic (polymers, oligomers, and dendrimers) or inorganic (ZnS, PbS) materials. In this study, we performed steady-state spectroscopic investigations to measure the photoluminescence (PL), absorption (A), transmission (T), and reflectance (R) of perovskite quantum dots (CsPbBr3) and ethylene vinyl acetate/terpene phenol (1%) (EVA-TPR (1%), or EVA) copolymer/perovskite composites in thin films with a thickness of 352 ± 5 nm. EVA is highly transparent because of its large band gap; furthermore, it is inexpensive and easy to process. However, the compatibility between PQDs and EVA should be established; therefore, a series of analyses was performed to compute parameters, such as the band gap, the coefficients of absorbance and extinction, the index of refractivity, and the dielectric constant (real and imaginary parts), from the data obtained from the above investigation. Finally, the optical conductivities of the films were studied. All these analyses showed that the EVA/PQDs were more efficient and stable both physically and optically. Hence, EVA/PQDs could become copolymer/perovskite active materials suitable for optoelectronic devices, such as solar cells and perovskite/polymer light-emitting diodes (PPLEDs).

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Scamporrino, Andrea A., Concetto Puglisi, Angela Spina, Maurizio Montaudo, Daniela C. Zampino, Gianluca Cicala, Giulia Ognibene et al. « Synthesis and Characterization of Copoly(Ether Sulfone)s with Different Percentages of Diphenolic Acid Units ». Polymers 12, n^o 8 (13 août 2020) : 1817. http://dx.doi.org/10.3390/polym12081817.

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New functionalized Poly(ether sulfone)s having different molar ratio (10, 20, 30, 50, 70, 100 mol%) of 4,4-bis phenoxy pentanoic acid unit (diphenolic acid; DPA) units were synthesized and characterized by (1H and 13C)-NMR, MALDI-TOF MS, FT-IR, DSC and DMA analyses. The microstructural analysis of the copolymers, obtained by 13C-NMR using an appropriate statistical model, shows a random distribution of copolymer sequences, as expected. The presence of different amount of DPA units along the polymer chains affects the chemical and physical properties of the copolymers. The Tg and the contact angle values decrease as the molar fraction of DPA units increases, whereas the hydrophilicity increases. NMR and MALDI-TOF MS analyses show that all polymer chains are almost terminated with hydroxyl and chlorine as end groups. The presence of cyclic oligomers was also observed by MALDI-TOF MS analysis.

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Fainleib, A. M. « Copolymers and interpenetrating polymer networks of thermoreactive nitrogen-containing resins. Mini review ». Polymer journal 42, n^o 4 (10 décembre 2020) : 245–53. http://dx.doi.org/10.15407/polymerj.42.04.245.

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In a short review the effective methods of optimization of structure and properties of high-performance polymers obtained from thermoreactive nitrogen-containing resins such as benzoxazines, bismaleimides, cyanate esters have been analysed. High crosslinked density copolymer thermosets are synthesized through chemical interactions between reactive functional groups, which belong to the monomers/oligomers used. The different possible processes such as copolymerization or formation of interpenetrating polymer networks are discussed. The high-performance polymers and composites from thermoreactive nitrogen-containing resins are effectively used in aerospace industry and microelectronics as materials possessing high thermal and thermooxidative stability, radiation and chemical resistance, low water absorption, low dielectric loss, high dimension stability and high adhesion to different substrate. The performance characteristics of this kind of materials can be controlled by changing their composition, temperature-time curing schedule, using catalytic systems. Keywords: copolymers, IPNs, thermoreactive resins, benzoxazine, bismaleimide, cyanate ester resins.

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Huh, J., O. Ikkala et G. ten Brinke. « Correlation Hole Effect in Comblike Copolymer Systems Obtained by Hydrogen Bonding between Homopolymers and End-Functionalized Oligomers ». Macromolecules 30, n^o 6 (mars 1997) : 1828–35. http://dx.doi.org/10.1021/ma9614398.

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Koizumi, Kyozo, et Toshiko Utamura. « High-performance liquid chromatography of gluco-oligomers on C18-bonded vinyl alcohol copolymer gel with alkaline eluents ». Journal of Chromatography A 436 (janvier 1988) : 328–33. http://dx.doi.org/10.1016/s0021-9673(00)94591-6.

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Huh, J., O. Ikkala et G. Ten Brinke. « Correlation hole effect in comblike copolymer systems obtained by hydrogen bonding between homopolymers and end-functionalized oligomers ». Macromolecular Symposia 121, n^o 1 (août 1997) : 123–31. http://dx.doi.org/10.1002/masy.19971210112.

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Kiose, O. O., et S. M. Savin. « COPOLYMERIZATION OF UNSATURATED OLIGOESTERS MODIFIED WITH NITROGEN-CONTAINING COMPOUNDS WITH METHYL METHACRYLATE ». Odesa National University Herald. Chemistry 28, n^o 1(84) (10 mai 2023) : 45–52. http://dx.doi.org/10.18524/2304-0947.2023.1(84).277059.

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In the present work, the kinetics of radical copolymerization in solution at the initial stages of polyglycol maleinate phthalates modified with nitrogen-containing compounds with methyl methacrylate in a ratio of 1:1 was studied. Cyclohexanone was used as a solvent, and benzoyl peroxide was used as an initiator. The study was carried out at temperatures of 50 and 60 °C by dilatometry using collapsible dilatometers and a centrifuge. 13 amine-containing compounds of different types were chosen as modifiers. Also, for comparison, the possibility of using amides and hydrazines as modifiers was checked. Polycondensation was carried out in an oil bath at 175 °C and with vigorous stirring with water withdrawal until a constant acid number was reached. It is shown that the addition of 0.1 mol/l modifier during the polycondensation of a mixture of maleic and phthalic anhydrides with ethylene glycol makes it possible to obtain an unsaturated oligoester, for which the temperature coefficient of the reaction of its copolymerization with methyl methacrylate is significantly reduced. This allows for non-isothermal curing to increase the volume of the copolymer block without the risk of overheating and destruction. Of the studied amines, para-aminoacetophenone turned out to be the most effective; its use as a modifier makes it possible to reduce the temperature coefficient of the reaction from 2.1 to 1.7. The rate of copolymerization at the initial stages for the studied modified systems decreases from 2 to 20 times. The results of the work allow us to propose a technology for the production of polymeric materials by molding them in blocks of much larger sizes than with the use of traditional unsaturated oligomers. Also, calculations were carried out according to a special technique and the maximum size of a copolymer block in the form of a cylinder was determined, in which the height is equal to the radius, which can be obtained by forming it in a non-isothermal mode in a thin layer form with convection air cooling and the maximum allowable temperature in the system is 90 °C. It is shown that the volume of such a block, when using some modified oligomers, increases significantly. Some physical and mechanical characteristics of the obtained copolymers with methyl methacrylate were determined, and it was shown that modification with nitrogen-containing compounds does not improve or worsen the studied characteristics.

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Baklan, N. S., G. V. Timofeeva, Е. V. Nosova, Yu N. Khoroshev, S. V. Luksha et O. V. Guniakova. « Investigation of new macroporous catalysts in the process of phenol alkylation by ethylene oligomers ». World of petroleum products 03 (2023) : 48–53. http://dx.doi.org/10.32758/2782-3040-2023-0-3-48-53.

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The features of phenol alkylation by higher alpha-olefins in order to obtain mono-substituted alkylphenols (o-AF and p-AF) using commercial industrial samples of sulfocationites: Hydrolite ZG CD552, ND-102 and the line of catalysts Purolite CT275DR/4503, CT275DR/4883, CT151DR, CT169DR, which belong to macroporous and are in different price categories. A feature of these cationites is a particularly strong matrix of regularly cross-linked divinylbenzene styrene copolymer. The structure of the granules combines the increased rigidity of the polymer mesh with a highly developed surface of the pores for exchange, which provides a large concentration of available exchange groups and high diffusion permeability of the granules. A comparative analysis of the catalytic activity of alkylation catalysts was carried out, which showed that, despite the high activity of all the studied catalysts in the reaction of alkylation of phenol with ethylene oligomers (OE) of the C16-C18 fraction, most of the studied catalysts showed low thermal stability and showed a tendency to rapid mechanical destruction. During the research, optimal technological parameters for each catalyst were established, including temperature and molar ratio of reagents, providing maximum yields of the target monoalkylphenol at the level of 97-98 %.

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Lefèbvre, Hervé, et Alain Fradet. « Bis(4-monosubstituted-5(4H)oxazolinones) as coupling agents for block copolymer synthesis : reaction with hydroxy-terminated oligomers ». Macromolecular Chemistry and Physics 199, n^o 12 (1 décembre 1998) : 2747–53. http://dx.doi.org/10.1002/(sici)1521-3935(19981201)199:12<2747 ::aid-macp2747>3.0.co;2-t.

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Nikulina, Nadezhda, Olga Dornyak, A. Dmitrenkov, Alexander Vostrikov, Konstantin Zhuzhukin et Natalya Chernaya. « Water absorption and swelling of Betula pendula ROTH wood modified with oligomers from by-products of polybutadiene production ». Forestry Engineering Journal 13, n^o 4 (12 février 2024) : 178–90. http://dx.doi.org/10.34220/issn.2222-7962/2023.4/11.

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Currently, natural wood and products based on it are in high demand. The technology of impregnation of low-value wood species on the example of B. pendula ROTH with an oligomeric material obtained from rubber production waste has been studied. Oligomers with a styrene content of 10 and 90% were obtained. In the first case, the low molecular weight copolymer had a molecular weight of 1100-1300, and in the second - 1700-2000. Impregnation of B. pendula ROTH wood was carried out in a solution of the obtained oligomer in toluene. In order to speed up the drying process of the protective coating and increase its strength, NF-1 siccative was introduced into the impregnation composition in an amount of 4-5%. The impregnation was carried out at temperatures of 60 and 120 ˚C, followed by heat treatment at temperatures of 100 and 160 ˚C. In the work, using the theory of experimental planning, a regression model was created that made it possible to describe the effects of a number of technological indicators on increasing the water and moisture resistance of modified wood. Verification of the coefficients of the models for significance was carried out using the Student's criterion. The obtained regression models make it possible to predict the characteristics of water resistance of birch wood modified due to its impregnation with a low-molecular copolymer containing styrene at specified values of technological parameters - the styrene content in the impregnating composition, the values of the impregnation temperature and heat treatment. It is shown that in order to increase the efficiency of the impregnation and heat treatment process, it is necessary to adhere to the minimum values of the considered temperature intervals, and the styrene content in the applied oligomeric product should be ~ 90% by weight. Modifying treatment of wood with an oligomer from by-products of polybutadiene production makes it possible to improve its water resistance. The use of the proposed impregnating compounds contributes to the disposal of waste and by-products of polybutadiene production.

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Sallam, Sahar, Yuanyuan Luo, Matthew L. Becker et Chrys Wesdemiotis. « Multidimensional mass spectrometry characterization of isomeric biodegradable polyesters ». European Journal of Mass Spectrometry 23, n^o 6 (6 juin 2017) : 402–10. http://dx.doi.org/10.1177/1469066717711401.

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The biodegradable polyester copolymer poly(propylene fumarate) (PPF) is increasingly utilized in bone tissue engineering studies due to its suitability as inert cross-linkable scaffold material. The well-defined poly(propylene fumarate) oligomers needed for this purpose are synthesized by post-polymerization isomerization of poly(propylene maleate), which is prepared by ring opening polymerization of maleic anhydride and propylene oxide. In this study, multidimensional mass spectrometry methodologies, interfacing matrix-assisted laser desorption ionization and electrospray ionization with mass analysis, tandem mass spectrometry fragmentation and/or ion mobility mass spectrometry, have been employed to characterize the composition, end groups, chain connectivity and isomeric purity of the isomeric copolyesters poly(propylene maleate)and poly(propylene fumarate). It is demonstrated that the polymerization catalyst is incorporated into the polymer chain (as the initiating chain end) and that the poly(propylene maleate) to poly(propylene fumarate) isomerization using an amine base proceeds with quantitative yield. Hydrolytic degradation is shown not to alter the double bond geometry of the poly(propylene fumarate) or poly(propylene maleate) chains.

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Bayramov, M. R., A. M. Maharramov, G. M. Mehdiyeva, Sh J. Guliyeva et M. A. Aghayeva. « SYNTHESIS OF CARBOXYLATE TYPE SORBENT BASED ON COOLIGOMERS OF 2-PROPENYLPHENOL AND FORMALDEHYDE AND STUDY OF THEIR FUNCTIONAL PROPERTIES FOR SORPTION OF URANYL IONS IN MODEL SYSTEMS ». Chemical Problems 21, n^o 1 (2023) : 85–92. http://dx.doi.org/10.32737/2221-8688-2023-1-85-92.

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Alkaline synthesis of double co-oligomers of 2-propenylphenol and formaldehyde (synthons) was carried out at 92-950C, for 3 hours and ratio of 1:2.5 mol (their yield are 93% of theory)Interaction of maleic anhydride with the obtained olygomers at 800C in the presence of 0.5% benzoyl peroxide for 10 hours produced copolymers of a three-dimensional cross-linked structure (with a yield of 90%). By treating them with hot water, a sorbent was obtained to contain both propenyl and carboxylate fragments in the structure - active centers of chemisorption. The functional sorption properties of the copolymer were studied under static conditions, in model water systems. The influence of the pH of the medium, the concentration of uranyl ions and the exposure time on the degree of their sorption at room temperature were studied and it was found that the best results are achieved at pH 6 and for 24 hours (R=93%). Uranyl ions can be easily desorbed with mineral acid and the crosslinked copolymers can be reused.

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Shibita, Ayaka, Seina Kawasaki, Toshiaki Shimasaki, Naozumi Teramoto et Mitsuhiro Shibata. « Stereocomplexation in Copolymer Networks Incorporating Enantiomeric Glycerol-Based 3-Armed Lactide Oligomers and a 2-Armed ɛ-Caprolactone Oligomer ». Materials 9, n^o 7 (19 juillet 2016) : 591. http://dx.doi.org/10.3390/ma9070591.

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Kim, C. « Polymer electrolytes prepared by polymerizing mixtures of polymerizable PEO-oligomers, copolymer of PVDC and poly(acrylonitrile), and lithium triflate ». Solid State Ionics 123, n^o 1-4 (août 1999) : 251–57. http://dx.doi.org/10.1016/s0167-2738(99)00119-8.

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Nyambura, Chris W., Elizabeth Nance et Jim Pfaendtner. « Examining the Effect of Polymer Extension on Protein–Polymer Interactions That Occur during Formulation of Protein-Loaded Poly(lactic acid-co-glycolic acid)-polyethylene Glycol Nanoparticles ». Polymers 14, n^o 21 (4 novembre 2022) : 4730. http://dx.doi.org/10.3390/polym14214730.

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Protein therapeutics have the potential to treat a wide range of ailments due to the high specificity in their function and their ability to replace missing or mutated genes that encode for key cellular processes. Despite these advantages, protein drugs alone can cause adverse effects, such as the development of cross-reactive neutralizing antibodies. Through the encapsulation of proteins into nanoparticles, adverse effects and protein degradation can be minimized, thus improving protein delivery to sites of interest in the body. Nanoparticles comprised of poly(lactic acid-co-glycolic acid)-polyethylene glycol (PLGA-PEG) diblock copolymer are promising protein delivery systems as they are well characterized, non-toxic, and biocompatible. Desirable nanoparticle characteristics, such as neutral surface charge and uniformity in size and dispersity, can be achieved but often require the iterative manipulation of formulation parameters. Chain conformations in the formulation process are very important, and determining whether or not an extended or semi-collapsed polymer chain in the presence of a protein results in more favorable binding has yet to be investigated experimentally. Therefore, this work used atomistic molecular dynamics to examine the role of polymer extension on protein binding and its impact on the encapsulation process within PLGA-PEG nanoparticles. Three polymers (PLGA-PEG, PLGA, and PEG) were evaluated and iduronate-2-sulphatase (ID2S) was used as a model protein. We found highly expanded PLGA-PEG conformations led to more favorable binding with ID2S. Furthermore, PEG oligomers were observed to undergo transient binding with ID2S that was generally less favorable when compared to the other polymer types. The results also suggest that the relaxation times of the PLGA homopolymer and the PLGA-PEG copolymer at different molecular weights in relevant solvent mediums should be considered.

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Arnould, Mark A., Rafael Vargas, Rita W. Buehner et Chrys Wesdemiotis. « Tandem Mass Spectrometry Characteristics of Polyester Anions and Cations Formed by Electrospray Ionization ». European Journal of Mass Spectrometry 11, n^o 2 (avril 2005) : 243–56. http://dx.doi.org/10.1255/ejms.746.

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Electrospray ionization of polyesters composed of isophthalic acid and neopentyl glycol produces carboxylate anions in negative mode and mainly sodium ion adducts in positive mode. A tandem mass spectrometry (MS/MS) study of these ions in a quadrupole ion trap shows that the collisionally-activated dissociation pathways of the anions are simpler than those of the corresponding cations. Charge-remote fragmentations predominate in both cases, but the spectra obtained in negative mode are devoid of the complicating cation exchange observed in positive mode. MS/MS of the Na+ adducts gives rise to a greater number of fragments but not necessarily more structural information. In either positive or negative mode, polyester oligomers with different end groups fragment by similar mechanisms. The observed fragments are consistent with rearrangements initiated by the end groups. Single-stage ESI mass spectra are also more complex in positive mode because of extensive H/Na substitutions; this is also true for matrix-assisted laser desorption ionization mass spectra. Hence, formation and analysis of anions might be the method of choice for determining block length, end group structure and copolymer sequence, provided the polyester contains at least one carboxylic acid end group that is ionizable to anions.

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Pugacheva, Tatyana A., Vladimir G. Kurbatov, Evgeniy V. Vaganov, Georgiy V. Malkov, Ksenya A. Tarusina, Vlada M. Organ, Elena V. Mitrofanova, Alexander E. Tarasov et Elmira R. Badamshina. « Curing of Poly(styrene-co-methyl methacrylate-co-2-hydroxyethyl methacrylate) Terpolymers in the Presence of Amino Compounds of Different Structures ». Polymers 15, n^o 9 (4 mai 2023) : 2187. http://dx.doi.org/10.3390/polym15092187.

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The process of curing the acrylic oligomers for rapid thermal curing coatings in the presence of hexa(methoxymethyl)melamine (HMMM), tetra(butoxymethyl)glycoluril (TBMG), and tetra(methoxymethyl)glycoluril (TMMG) has been studied. When HMMM is used as a hardener, the content of hydroxyl groups in the terpolymer and also the crosslinking agent concentration have little effect on the initial cure rate. It has been established that during the curing of the TMMG composition, the amount of the network polymer and the initial curing rate decrease at short curing times only. It has also been revealed that the use of butoxy groups instead of methoxy groups as blocking agents leads both to a decrease in the initial cure rate and the gel fraction limiting value from 98 to 80%. When it comes to TBMG-containing compositions, a decrease in the part of hydroxyl groups in the copolymer leads to a significant fall in the initial curing rate and also in the gel fraction content. Regardless of the crosslinking agent used, an acceleration of the curing process is observed with an increase in the catalyst content in the compositions.

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P'yanova, Lidia G., Vladimir A. Likholobov, Maria S. Drozdetskaya, Anna V. Sedanova et Natalia V. Kornienko. « A study of desorption (migration) of oligomers/copolymer of hydroxy acids from the surface of modified sorbents in aqueous solutions ». Materials Today : Proceedings 5, n^o 12 (2018) : 25916–20. http://dx.doi.org/10.1016/j.matpr.2018.08.003.

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Tieghi, Giuseppe, Marinella Levi et Roberta Imperial. « Viscosity versus molecular weight and temperature of diolic perfluoro-poly(oxyethylene-ran-oxymethylene) oligomers : role of the end copolymer effect ». Polymer 39, n^o 5 (mars 1998) : 1015–18. http://dx.doi.org/10.1016/s0032-3861(97)00383-2.

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Lee, Chang Hyun, Desmond VanHouten, Ozma Lane, James E. McGrath, Jianbo Hou, Louis A. Madsen, Justin Spano et al. « Disulfonated Poly(arylene ether sulfone) Random Copolymer Blends Tuned for Rapid Water Permeation via Cation Complexation with Poly(ethylene glycol) Oligomers ». Chemistry of Materials 23, n^o 4 (22 février 2011) : 1039–49. http://dx.doi.org/10.1021/cm1032173.

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Zhuravkov, Sergey P., Elena L. Boytsova et Anastasia V. Slavinskaya. « STABILIZATION OF POLYETHYLENE AND OTHER POLYOLEFINS BY PHENOTHIAZINE DERIVATIVES ». ChemChemTech 67, n^o 12 (12 novembre 2024) : 96–101. https://doi.org/10.6060/ivkkt.20246712.6941.

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This paper presents the results of the synthesis and study of the thermostabilizing properties of a number of new derivatives, as well as previously known derivatives of Phenothiazine (PT). The objects of the study were: cis-10-propenylphenothiazine (cis-10-PPT), 1-ethyl-2-methyl-3-(10H-phenothiazin-10-yl)-2,3-dihydro-1H-pyrido[3,2,1-kl]phenothiazine. Propenylphenothiazine dimer (DPРT),1-ethyl-2-methyl-3-(5-oxido-10H-phenothiazin-10-yl)-2,3-dihydro-1H-pyrido[3,2,1-kl]phenothiazine 7-oxide. S-oxide (DPРTО),1-ethyl-2-methyl-1H-pyrido-[3,2,1-k,l]phenothiazine. Pyridophenothiazine (PyrPT) and a mixture of two fractions of 10-propenylphenothiazine oligomers: 1-ethyl-2-methyl-3-(10H-phenothiazin-3-yl)-2,3-dihydro-1H-pyrido[3,2,1-kl]phenothiazine (ОPРT 1) and 3,7-bis(1-ethyl-2-methyl-2,3-dihydro-1H-pyrido[3,2,1-kl]phenothiazin-3-yl)-10H-phenothiazine (ОPРT 2). A well-known industrial stabilizer, Pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (Irganox 1010), was used as a comparison sample. Irganox 1010 is an antioxidant based on spatially hindered phenol with a high molecular weight, has very low volatility, is used as an antioxidant and heat stabilizer for polypropylene, polyethylene, impact-resistant polystyrene, poly-4-methyl-pentene. To evaluate the stabilizing effect of PT derivatives, a powder of unstabilized templene (a copolymer of poly-4-methylpentene-1 and n-hexene) was used. Thermogravimetric (TGA) and differential thermal analysis (DTA) methods were used to study the thermal oxidative degradation of polymer compositions based on templene in open and closed crucibles. For each tested stabilizer sample, the following were determined: the temperature of the beginning of decomposition of the polymer composition (Tb.d., °C), the decomposition temperature of 1% of the mass of the tested polymer composition (T1%, °C). Based on the experimental data obtained, the following were calculated: the thermal stability of the tested compositions, the effective activation energy (Ea). The thermostabilizing effect of additives in compositions based on ethylene copolymer with vinyl acetate (savylene), high-pressure polyethylene (HDPE) was evaluated according to TU 301-05-91, according to the accumulation time of acidic polymer degradation products in them during aging at 180 °C and 160 °C in oxygen current (pH), as well as by the change in the melt flow index in the process of holding the polymer in air at 200 °C for two hours (for savylene and HDPE). In addition, the effectiveness of the additives was evaluated by changing the mechanical properties of the compositions: tensile yield strength (σt), elongation (ε, %). It was found that mixture of two fractions oligomers (OPPT 1) and (OPPT 2) products synthesized from cis-10-PPT have a sufficiently high stabilizing effect. For citation: Zhuravkov S.P., Boytsova E.L., Slavinskaya A.V. Stabilization of polyethylene and other polyolefins by phenothiazine derivatives. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2024. V. 67. N 12. P. 96-101. DOI: 10.6060/ivkkt.20246712.6941.

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Esmaili, Mansoore, Brian P. Tancowny, Xiongyao Wang, Audric Moses, Leonardo M. Cortez, Valerie L. Sim, Holger Wille et Michael Overduin. « Native nanodiscs formed by styrene maleic acid copolymer derivatives help recover infectious prion multimers bound to brain-derived lipids ». Journal of Biological Chemistry 295, n^o 25 (1 mai 2020) : 8460–69. http://dx.doi.org/10.1074/jbc.ra119.012348.

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Prions are lipidated proteins that interact with endogenous lipids and metal ions. They also assemble into multimers and propagate into the infectious scrapie form known as PrPSc. The high-resolution structure of the infectious PrPSc state remains unknown, and its analysis largely relies on detergent-based preparations devoid of endogenous ligands. Here we designed polymers that allow isolation of endogenous membrane:protein assemblies in native nanodiscs without exposure to conventional detergents that destabilize protein structures and induce fibrillization. A set of styrene–maleic acid (SMA) polymers including a methylamine derivative facilitated gentle release of the infectious complexes for resolution of multimers, and a thiol-containing version promoted crystallization. Polymer extraction from brain homogenates from Syrian hamsters infected with Hyper prions and WT mice infected with Rocky Mountain Laboratories prions yielded infectious prion nanoparticles including oligomers and microfilaments bound to lipid vesicles. Lipid analysis revealed the brain phospholipids that associate with prion protofilaments, as well as those that are specifically enriched in prion assemblies captured by the methylamine-modified copolymer. A comparison of the infectivity of PrPSc attached to SMA lipid particles in mice and hamsters indicated that these amphipathic polymers offer a valuable tool for high-yield production of intact, detergent-free prions that retain in vivo activity. This native prion isolation method provides an avenue for producing relevant prion:lipid targets and potentially other proteins that form multimeric assemblies and fibrils on membranes.

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SISYUK, V. G., L. I. ZEL, N. G. UGRO et S. M. OSTAPIUK. « MODIFICATION OF VEGETABLE OILS WITH REACTIVE COMPOUNDS FOR THE PRODUCTION OF PRINTING INKS ». Polymer journal 45, n^o 4 (20 décembre 2023) : 286–92. http://dx.doi.org/10.15407/polymerj.45.04.286.

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The modification of existing paints and varnishes based on alkyd resins, as well as the creation of new film formers using functionalised oligomers to improve the properties of materials in use, has been carried out. The aim of the work is to study vegetable oils used in the production of printing inks and to modify them in order to improve their technological properties. The work carried out allows the use of printing inks based on modified vegetable oils, with the expansion of their scope of application in the production of various printed products. The modification of vegetable oils was carried out by interaction with synthesised urethane-containing reactive block copolymers. Modification of mustard oil allows to change its structure, to increase its molecular weight by oligomerisation of the oil with obtaining of branched structure. Modified vegetable oils provide fast drying alkyd coatings, even in air. The properties of modified oils, the rate of film formation depend on the chemical nature of the block copolymer, its reactivity. The main processes of oil film structuring are due to oxidative and thermal polymerisation of double bonds of fatty acid residues. Optimisation of the vegetable oil modification process has been carried out, a formulation for the production of printing inks has been developed and production tests have been carried out with positive results.

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