Journal articles on the topic 'Polypropylene expansé'
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1
Gulieva, T. M. "COPPER-CONTAINING NANOCOMPOSITES ON THE BASIS OF ISOTACTIC POLYPROPYLENE AND BUTADIENE-NITRILE RUBBER." Azerbaijan Chemical Journal, no. 3 (September 28, 2021): 38–43. http://dx.doi.org/10.32737/0005-2531-2021-3-38-43.
Abstract:
The influence of additives of nanofillers containing nanoparticles of copper oxides stabilized by a polymer matrix of maleinized high-pressure polyethylene obtained by the mechano-chemical method on the structure and properties features of metal-containing nanocomposites based on isotactic polypropylene and butadiene-nitrile rubber by x-ray phase and differential thermal analyses is studied. The improvement of strength, deformation and rheological parameters, as well as thermal-oxidative stability of the obtained nanocomposites was revealed, that is probably due to the synergistic effect of interaction of copper-containing nanoparticles with maleic groups of maleinated high-pressure polyethylene. It is shown that nanocomposites based on isotactic polypropylene and butadiene-nitrile rubber can be processed both by pressing method and by injection molding and extrusion methods that expands the scope of its application
2
Liu, Changkun, Jizhen Jia, Ji’an Liu, and Xiaoyan Liang. "Hg selective adsorption on polypropylene-based hollow fiber grafted with polyacrylamide." Adsorption Science & Technology 36, no. 1-2 (January 27, 2017): 287–99. http://dx.doi.org/10.1177/0263617416689480.
Abstract:
A novel polypropylene hollow fiber membrane with a new function of selective adsorption of mercury ions in aqueous solutions was successfully prepared. The surface of the polypropylene hollow fiber membrane was initially modified with polydopamine by surface polymerization, and subsequently grafted with polyacrylamide (PAM) polymer brush via the surface initiated atom transfer radical polymerization (SI-ATRP) technique (thereafter named as PP-PAM). This study investigated the adsorption performance of Hg(II) ions by PP-PAM and the effect of various influencing factors on Hg(II) ion adsorption. The experiment indicated that the Hg(II) adsorption capacity of the PP-PAM increased with the increase of the pH, and the Hg(II) adsorption kinetics was consistent with the pseudo-second-order kinetic model. The adsorption isotherm followed the Langmuir model, with the maximum adsorption capacity calculated to be 0.854 mmol/g for Hg(II) ions. The adsorption study in multi-component system indicated that PP-PAM preferentially adsorbs Hg(II) over Pb(II) ions, with significant adsorption capacity difference of the two heavy metal ions. This study provided an efficient method for the preparation of the adsorptive polypropylene hollow fiber membrane, which expands its application for the selective removal of heavy metal ions.
3
Potapova, Ekaterina, Ekaterina Dmitrieva, Aung Kyaw Nian, and Elena Tsvetkova. "Gypsum Composite Reinforced with Polymer Fibers." Key Engineering Materials 910 (February 15, 2022): 880–86. http://dx.doi.org/10.4028/p-dgyem5.
Abstract:
Composite gypsum binders harden quickly, gain strength quickly and have positive environmental properties. Moreover, they are characterized by increased moisture resistance, which significantly expands the field of application of such gypsum materials. Dispersed reinforcement of composite gypsum binders with polypropylene fibers makes it possible to obtain composites characterized by high performance properties. On basis of developed compositions of gypsum-cement-pozzolanic and composite gypsum binders with polymer fibers, gypsum composites have been created, characterized by increased strength, water resistance, frost and corrosion resistance.
4
Barczewski, Mateusz, Danuta Matykiewicz, Olga Mysiukiewicz, and Paweł Maciejewski. "Evaluation of polypropylene hybrid composites containing glass fiber and basalt powder." Journal of Polymer Engineering 38, no. 3 (March 28, 2018): 281–89. http://dx.doi.org/10.1515/polyeng-2017-0019.
Abstract:
AbstractPolypropylene composites filled with inorganic fillers are widely used due to their good mechanical and thermal properties. The modification efficiency of filler incorporated into thermoplastic polymer strongly depends on its shape and dimension. Therefore, the development of novel hybrid composites modified with particle and fibrous shaped fillers expands the range of thermoplastic composite applications. This work investigates the influence of glass fiber and basalt powder and their shape on the mechanical properties of polypropylene-based composites. Mechanical properties of hybrid composites were evaluated using static tensile test, impact resistance, and hardness measurements. The thermomechanical stability of the materials was evaluated via dynamic mechanical thermal analysis. Results indicated that the incorporation of inorganic fillers significantly improved the composite sample stiffness at a wide range of temperatures. The research was complemented with structure investigations realized using scanning electron microscopy. Moreover, the incorporation of basalt powder, which is well known for its low friction coefficient, improved the processing properties, as proven by the melt flow index test.
5
Kurbanova, N. I., T. M. Gulieva, and N. Ya Ischenko. "Properties of nanocomposites based on isotactic polypropylene and high-pressure polyethylene with metal-containing nanofillers." Perspektivnye Materialy, no. 9 (2020): 59–64. http://dx.doi.org/10.30791/1028-978x-2020-9-59-64.
Abstract:
The effect of additives of nanofillers (NF) containing nanoparticles (NP) of copper oxide, stabilized by a polymer matrix of maleized polyethylene (MPE), obtained by the mechanochemical method, on the properties of composites based on isotactic polypropylene (PP) and high-pressure polyethylene (PE) was studied by X-ray phase (XRD) and thermogravimetric (TGA) analyzes. The enhancement of strength, deformation, and rheological parameters, as well as the thermo-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is due to the synergistic effect of the interaction of copper-containing nanoparticles with anhydride groups of MPE. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing and injection molding and extrusion, which expands the scope of its application.
6
Kurbanova, N. I., S. K. Ragimova, N. A. Alimirzoeva, N. Ya Ishenko, and V. V. Medyakov. "Composites based on isotactic polypropylene and high-pressure polyethylene with zink-containing nanofillers." Perspektivnye Materialy 11 (2021): 47–53. http://dx.doi.org/10.30791/1028-978x-2021-11-47-53.
Abstract:
The effect of nanofiller (NF) additives containing zink oxide nanoparticles stabilized by a polymer matrix of high pressure polyethylene obtained by the mechanochemical method on the structure and properties of metal-containing nanocomposites based on isotactic polypropylene (PP) and high pressure polyethylene (PE) using differential thermal (DTA) and X-ray phase (XRF) analyzes. The improvement of strength, deformation and rheological parameters, as well as thermal-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is associated with the synergistic effect of interfacial interaction of zink — containing nanoparticles in the PE matrix with the components of the PP/PE polymer composition. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing method and by injection molding and extrusion methods, which expands the scope of its application.
7
Kurbanova, N. I., S. K. Ragimova, and T. M. Guliyeva. "Composites based on isotactic polypropylene and high pressure polyethylene with nichel-containing nanofillers." Perspektivnye Materialy 2 (2024): 51–57. http://dx.doi.org/10.30791/1028-978x-2024-2-51-57.
Abstract:
The effect of nanofiller (NF) additives containing nickel oxide nanoparticles stabilized by a polymer matrix of high pressure polyethylene (PE) obtained by the mechanochemical method on the structure and properties of metal-containing nanocomposites based on isotactic polypropylene (PP) and high pressure polyethylene(PE) using differential thermal (DTA) and X-ray phase (XRF) and SEM analyzes. The improvement of strength, deformation and rheological parameters, as well as thermal-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is associated with the synergistic effect of interfacial interaction of nickel-containing nanoparticles in the PE matrix with the components of the PP/PE polymer composition. It is shown that nanocomposites based on PP/PE/NF can be processed both by pressing method and by injection molding and extrusion methods, which expands the scope of its application.
8
Kurbanova, N. I., S. K. Ragimova, N. A. Alimirzoeva, and N. Ya Ishenko. "Copper-containing nanocomposites on the basis of isotactic polypropylene and butadiene-nitrile rubber." Perspektivnye Materialy 5 (2021): 76–81. http://dx.doi.org/10.30791/1028-978x-2021-5-76-81.
Abstract:
The influence of additives of nanofillers (NF) containing nanoparticles of copper oxides stabilized by a polymer matrix of high-pressure polyethylene (PE) obtained by the mechanochemical method on the structure and properties features of metal-containing nanocomposites based on isotactic polypropylene (PP) and butadiene-nitrile rubber (BNK) is studied by X-ray phase (XRD) and differential thermal analyses(DTA). The improvement of strength, deformation and rheological parameters, as well as thermal-oxidative stability of the obtained nanocomposites was revealed, which, apparently, is associated with the synergistic effect of interfacial interaction of copper-containing nanoparticles in the PE matrix with the components of the PP/BNK polymer composition. It is shown that nanocomposites based on PP/BNK/NF can be processed both by pressing method and by injection molding and extrusion methods, which expands the scope of its application.
9
MOODLEY, R. S., R. GOVINDEN, and B. ODHAV. "The Effect of Modified Atmospheres and Packaging on Patulin Production in Apples." Journal of Food Protection 65, no. 5 (May 1, 2002): 867–71. http://dx.doi.org/10.4315/0362-028x-65.5.867.
Abstract:
This study was undertaken to determine the effectiveness of modified atmospheres and packaging materials on the growth of Penicillium expansum and patulin production in apples. Granny Smith apples were surface sterilized with 76% ethanol and inoculated with 0.1 ml of a 1.1 × 107 spore/ml P. expansum spore suspension. The apples were packaged either in polyethylene (PE) or polypropylene (PP) and treated with three different gas combinations, viz., 58% CO2/42% N2, 48% CO2/52% N2, and 88% CO2/12% N2, and were then incubated for 14 days at 25°C. Fungal growth was monitored every 2 to 4 days by measuring radial growth from the point of inoculation. After the 14th day, apples were pulped, and patulin was extracted, purified, and quantified by high-performance liquid chromatography. PP did not inhibit fungal growth in any of the atmospheres tested, and it only inhibited patulin production in atmospheric gas and 58% CO2/42% N2. PE was very effective and inhibited fungal growth by four- or fivefold, depending on the modified atmosphere. Patulin production in PE-packaged apples was almost completely inhibited by all three gas combinations. Gas chromatographic analysis of the PE-packaged samples before and after the incubation period showed that CO2 levels dropped and N2 levels increased for all of the atmospheres tested. Our studies showed conclusively that PE is an excellent packaging material for the storage of apples since it inhibited the growth of P. expansum, thereby allowing <3.2 μg/ml of patulin to be produced, regardless of gaseous environment.
10
Levin, R. E., M. A. Shamraeva, I. M. Larina, D. S. Bormotov, S. I. Pekov, A. S. Shivalin, S. V. Silkin, et al. "THE DEVELOPMENT OF A METHOD FOR DIRECT MASS SPECTROMETRIC ANALYSIS OF BIOLOGICAL SAMPLES USING POROUS SAMPLERS." Aerospace and Environmental Medicine 55, no. 1 (2021): 99–103. http://dx.doi.org/10.21687/0233-528x-2021-55-1-99-103.
Abstract:
The paper presents a method for rapid multi-omics investigation of biological samples using polypropylene bulk porous samplers. The use of porous samplers makes it easy to collect samples from the surface of the skin, mucous membranes, and biological fluids even in a field, and the surfaces of wounds and injuries. Collected samples do not require special storage conditions, and the samplers are lightweight and very compact. They can be used to monitor the condition of cosmonauts before, during, and after the spaceflight with the same sample collection method. The analysis of biomaterial applied to the sampler is performed using direct mass spectrometry methods, similar to the dried blood spot technique that is already used in clinical practice. However, bulk porous samplers allow expanding the range of analytes ionization conditions, which increases the stability and reliability of the ionization process, which expands the variety of analyzed molecules. The proposed method can be used to study compounds of various classes, including proteins, lipids, and metabolites, to systematically monitor the status of people in extreme conditions (athletes, astronauts), or to study the condition of patients in the clinic.
11
Kovaleva, I. A., I. V. Bazuyev, Yu V. Prybytkov, and N. A. Khodosovskaya. "Ensuring the safety of the surface of calibrated rolled products in the conditions of small-grade wire mill 370/150 OJSC «BSW – Management Company of the Holding «BMC»." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 4 (January 20, 2020): 53–57. http://dx.doi.org/10.21122/1683-6065-2019-4-53-57.
Abstract:
One of the important tasks is to deliver to the consumer a calibrated high-quality metal in a saleable condition, which requires protection from atmospheric corrosion and adverse climatic factors, protection from contamination and mechanical damage for the period of transportation to the consumer by motor transport, and storage at intermediate warehouses before going into production. A comprehensive system approach is needed to preserve the quality and appearance of the products on the way from the manufacturer to the consumer. The use of modern packaging materials, such as paper with corrosion inhibitor and polypropylene fabric reinforcement, will allow to obtain permanent guaranteed protection of the rolled surface and expands the possibilities of transportation and sales markets of metal products. The testing stage of the corrosion inhibitor included the determination of its protective properties. It is established that the advantage of packaging of rolled products in anticorrosive paper is that it, combining the functions of packaging means and means of preservation, allows you to completely abandon the expensive and time-consuming preservation of metal products with oils and greases. The use of a volatile corrosion inhibitor in the composition of the paper provides full protection of rolled products.
12
Oh, Moo-Hwan, Taeho Kim, David W. Fredriksson, and Judson DeCew. "Structural Analysis of a Subsurface Cage for Sea Cucumber, Stichopus japonicus, Grow-out Using Numerical Modeling Techniques." Marine Technology Society Journal 46, no. 5 (September 1, 2012): 55–66. http://dx.doi.org/10.4031/mtsj.46.5.8.
Abstract:
AbstractThe structural characteristics of a subsurface cage system for sea cucumber, Stichopus japonicus, grow-out were analyzed by using numerical modeling techniques. The cage system was constructed of polypropylene pipe and netting and weighted to sit on the seafloor bottom. Inside the cage, concrete blocks were used for animal aestivation and weight and a thin-plated device was mounted for animal movement. Environmental loads on the structure, resulting from a prescribed irregular wave field with and without currents, were first determined with a Morison equation-type finite element model. The structural response of beam and truss cage components was then calculated with the software MSC.MARC/Mentat. In addition to the irregular wave and current input forcing parameters of the structure, response was also calculated for possible forces incurred during lifting operations. Reaction loads, bending moments, axial tensions, and von Mises stresses of the sea cucumber cage structure were calculated for evaluation. The results of the study indicate that the combination of numerical model analyses presented can be used to assess structural integrity of these subsurface cage systems. These techniques will become more important as the industry expands and economics of scale promotes the construction of larger sea cucumber containment structures.
13
Fürst, Richard, Petr Hejtmánek, Tomáš Vlach, Jakub Řepka, Vladimír Mózer, and Petr Hájek. "Experimental Evaluation of Carbon Reinforced TRC with Cement Suspension Matrix at Elevated Temperature." Polymers 14, no. 11 (May 27, 2022): 2174. http://dx.doi.org/10.3390/polym14112174.
Abstract:
Textile-reinforced concrete (TRC) is a new composite material comprising high-performance concrete and textile reinforcement from textile yarns with a matrix, usually consisting of epoxy resins (ER). The most significant advantage of ER is the homogenization of all filaments in the yarn and full utilization of its tensile potential. Nevertheless, ER matrix is a critical part of TRC design from the perspective of the fire resistance due to its relatively low resistance at temperatures of approximately 120 ∘C. This work expands the previously performed mechanical tests at normal temperatures with cement suspension (CS) as a non-combustible material for the yarn matrix. Here, the mechanical properties of CS matrix at elevated temperatures were verified. It was found that the addition of polypropylene fibers into HPC negatively affected the mechanical results of CS matrix specimens. Simultaneously, thermal insulation effect of the covering layers with different thicknesses did not significantly influence the residual bending strength of specimens with CS matrix and achieved similar results as reference specimens. Furthermore, all specimens with ER matrix progressively collapsed. Finally, CS as a textile reinforcement of yarn matrix appears to be a suitable solution for increasing the temperature resistance of TRC structures and for substituting synthetic resins.
14
Hu, Yanyan, and Linlin Ma. "Effect of Surface Treatment of Polypropylene (PP) Fiber on the Sulfate Corrosion Resistance of Cement Mortar." Materials 14, no. 13 (July 1, 2021): 3690. http://dx.doi.org/10.3390/ma14133690.
Abstract:
Sulfate erosion is one of the most complex and harmful chemical corrosion actions. Following sulfate erosion, concrete expands, cracks, dissolves, peels off, and decreases in strength, which affects the durability of structures. Polypropylene fiber (PP) is widely used in various concrete structures because of its good mechanical properties and chemical corrosion resistance. However, PP fiber has a number of shortcomings, such as a smooth surface, poor hydrophilicity, lack of active groups in the molecular chain, and agglomeration and poor dispersion in cement-based materials. These issues limit its application in cement-based materials. Although the use of a silane coupling agent to modify the surface of PP fiber is effective, the influence of treated PP fiber on the sulfate resistance of cement-based materials is not significant. In this study, a PP fiber treated with a silane coupling agent was used to examine effects of different cement-to-sand ratios (C/S) and dosages of the treated PP fiber on the sulfate erosion resistance of cement mortar. Furthermore, the apparent morphology, mass loss rate, flexural strength, corrosion resistance coefficient, and microstructure of the concrete were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed that the PP fiber became rough after modification. Active groups were introduced on the fiber surface, which were well dispersed in the mortar and formed a good network distribution structure in the cement mortar, thereby slowing the erosion rate of the PP fiber mortar in a sodium sulfate solution. At a C/S ratio of 1:1 and a treated fiber dosage of 0.6%, the treated fiber mortar has exhibited good sulfate resistance. In addition, the monofilament fiber immersion test revealed that a layer of sodium sulfate crystals was deposited on the fiber surface, thereby increasing the roughness of the fiber surface and the pull-out force of the fiber from the cement matrix, this result indicated that the interfacial adhesion between the treated PP fiber and cement matrix was improved, which in turn led to the improvement in the sulfate erosion resistance of the treated PP fiber.
15
"Sumitomo to expand polypropylene capacity." Pump Industry Analyst 2007, no. 9 (September 2007): 3. http://dx.doi.org/10.1016/s1359-6128(07)70321-x.
16
"Milliken expands solutions for polypropylene recyclers." Additives for Polymers 2021, no. 11 (November 2021): 3–4. http://dx.doi.org/10.1016/s0306-3747(21)00195-0.
17
Liu, Feng, Shuhao Li, Yulei Zhao, Shakeel Akram, Li Zhang, and Zhi Fang. "Effect of pulse voltage rise rate on the polypropylene surface hydrophilic modification by ns pulsed nitrogen DBD." Plasma Science and Technology, May 13, 2023. http://dx.doi.org/10.1088/2058-6272/acd529.
Abstract:
Abstract The nanosecond (ns) pulsed nitrogen dielectric barrier discharge (DBD) is employed to enhance the hydrophilicity of polypropylene (PP) surface and improve its application effect. The discharge characteristics of the ns pulsed nitrogen DBD with different pulse rise times (from 50 ns to 500 ns) are investigated by electrical and optical diagnostic methods and the discharge uniformity is quantitatively analyzed by image processing method. To characterize the surface hydrophilicity, the water contact angle (WCA) is measured, and the physical morphology and chemical composition of PP before and after modification are analyzed to explore the effect of plasma on PP surface. According to the experimental results the discharge becomes more uniform and the energy efficiency, electron density and electron temperature are all escalated at 50 ns pulse rise time than at the other pulse rise times. The PP surface treated with 50 ns pulse rise time DBD has a lower WCA (~47°), while the WCA of PP treated with 100 to 500 ns pulse rise time DBD expands gradually (~50°-57°). According to the fixed-point WCA values study the DBD-treated PP surface has superior uniformity under 50 ns pulse rise time (3° variation) than under 300 ns pulse rise time (8° variation). After DBD treatment, the surface roughness and hydrophilic oxygen-containing groups on the surface, i.e., hydroxyl (−OH) and carbonyl (C=O) have played the significant role to improve the hydrophilicity of the sample’s surfaces. The short pulse voltage rise time enhances the reduced electric field strength (E/n) in the discharge space and improves the discharge uniformity, which makes relatively sufficient physical and chemical reactions have taken place on the PP surface, resulting in better treatment uniformity.
18
Wolf de Goes, Caroline Marção, Patricia Stella Pucharelli Fontanini, Lia Lorena Pimentel, and Ana Elisabete Paganelli G. de Avila Jacintho. "ANÁLISE DA APLICAÇÃO DE CONCRETO COM ADIÇÃO DE MACROFIBRAS ESTRUTURAIS SINTÉTICAS E MICROFIBRAS DE VIDRO ANTI-CRACK AR EM PISOS." REEC - Revista Eletrônica de Engenharia Civil 12, no. 1 (June 15, 2016). http://dx.doi.org/10.5216/reec.v12i1.37400.
Abstract:
RESUMO: As fibras vêm sendo muito utilizadas para reforçar o concreto, e hoje, existe uma grande variedade delas, por exemplo, fibras de polipropileno, fibras sintéticas, fibras com baixo teor de carbono, e fibras de polietileno. O emprego das fibras nas misturas cimentícias promove diversas melhorias ao concreto armado, como, aumento da resistência à fadiga e ao impacto; tenacidade à flexão; aumento da capacidade de absorção de energia, que transferem tensões através de fissuras, fazendo com que reduza sua propagação e expansão; e maior ductilidade, pois em concretos não reforçados, após a primeira fissura, o concreto se torna deficiente. Nesta pesquisa foram apresentadas as principais vantagens da adição de macrofibras estruturais sintéticas e microfibras de vidro ao concreto em pisos para redução de fissuras. O presente trabalho tem o objetivo de apresentar um Estudo de Caso e propor dois novos traços de concreto com adição de macrofibras estruturais sintéticas e microfibras de vidro como reforço de pisos e um traço referência sem adição de fibras. Foram analisadas as resistências à compressão axial, diametral, tração na flexão, impacto e módulo de elasticidade, dos novos traços e do concreto utilizado no Estudo de Caso, bem como, foram apresentadas as vantagens e desvantagens dessa mistura em relação ao concreto convencional. ABSTRACT: The fibers have been widely used for reinforcing concrete, and today, there are a plenty of them, like, polypropylene fibers, synthetic fibers, fibers with low carbon content andpolyethylene fibers. The use of fibers in cementitious mixtures promotes several improvements to the concrete, as, increased resistance to fatigue and impact, flexural toughness, increased capacity of energy absorption, that transfer stresses through the cracks, reducing the propagation and expansion, and more ductility, because unreinforced concrete, after the first fissure, the concrete becomes disabled. This research will analyze the main advantages of the application of macro synthetic structural fibers and micro AR glass fibers to concrete floors to reduce cracks. This paper aims to present a case study and two new features have been proposed using macro synthetic structural fibers and micro AR glass fibers addition on reinforced concrete on floors and one feature without fibers. Resistance to axial compression, diametrical compression, flexural thoughness, impact resistance and elasticity module were analyzed of the new features and the concrete used at case study, as well as the advantages and disadvantages of this mixture comparing to conventional concrete.