Polymer properties

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  • Polymers are materials of very high molecular weight that are found to have multifarious applications in our modern society. They usually consist of several structural units bound together by covalent bonds [1,2]. For example, polyethy- lene is a long-chain polymer and is represented by

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  • Is a branch of polymer science dealing with analysis and characterisation of polymers. üThe complication of macromolecular chains, the dispersion in molecular weight, tacticity, crystallinity, orientation, composition of polymers etc. and complex morphological systems ⇒ analysis of polymer ≠ the small organic materials ⇒ Focus on viscoelastic properties, dynamic mechanical testing.

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  • Organic chemistry is a subdiscipline within chemistry involving the scientific study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of carbon-based compounds, hydrocarbons, and their derivatives. Organic compounds are structurally diverse. The range of application of organic compounds is enormous. They either form the basis of, or are important constituents of, many products including plastics, drugs, petrochemicals, food, explosives, and paints....

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  • New approaches to tailor-made cellulose/starch/lignin-synthetic polymer graft copolymers with precise control over molecular weight, degree of substitution, backbone-graft linkage, and the overall grafting process are being studied. Cross-linked graft copolymers with exactly defined polymer chain segments between crosslink points have been prepared. The graft copolymers exhibit a two-phase morphology and can function effectively as compatibilizers/interfacial agents to alloy cellulosic and lignocellulosic materials with synthetic polymers.

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  • Since the establishment of the conductive properties of intrinsic conductive polymers, a huge variety of basic and applied research has been carried out, involving different polymers, copolymers, blends, mixtures and composites. Thus, fundamental understanding of physical and chemical properties of these materials has been sought, while the applied aspects have advanced very rapidly, crossing the boundaries between disciplines. Today, the applications of conducting polymers in various fields such as neuroscience, nanotechnology and green chemistry, are easily found.

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  • With contributions from many of the world's leading scientists in the field of dendritic research and development, Dendrimers and Other Dendritic Polymers provides a comprehensive review of this rapidly expanding and exciting new field of polymer science. Of interest to academia and industry alike, this book covers the synthesis, characterization, unique properties, potential for novel applications and technical challenges associated with these polymers.

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  • The mechanical and electrical properties of polymer composite materials based on bamboo wafer reinforced phenol formaldehyde resin have been studied. The tensile, flexural and impact strengths of composite materials have been decreased significantly when using the short bamboo fibre instead of the bamboo wafer.

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  • Tham khảo sách 'mechanical properties of polymers and composites nielsen 2012', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

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  • Tham khảo sách 'reinforced polymer composites l. tong, a.p. mouritz and m.k. bannisterelsevier', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

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  • Polymer applications have become more demanding as industry continuously turns to more microscopic parts. Due to the interactions of the polymer chains with the supporting surface and the air interface, the thinner films required for such applications have distinctly different properties than those of the well-defined bulk systems. The goal of the current research is to elucidate the behavior of ultrathin films.

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  • This paper presents the results of the effect content of short bamboo fiber prepared by mechanical method and alkaline treatment on mechanical properties of polymer composites (PC) based on polypropylene (PP). With content of 50% in composition, the tensile, the flexible and impact strengths have been increased as 24%, 23% and 40%, respectively in comparison with original PP. Using the prepared bamboo fiber by steam explosion method in stead of mechanical one, the tensile strength of composite increases 16%, mean while the flexible and impact strength have the equivalent value.

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  • This paper present the results of research on designing mold for vacuum infusion technique for preparation the polymer composite material. Specimens of varrious methods of vacuum technique have been prepared and their mechanical and structural properties have been studied. The results show that material obtained from vacuum assisted technique have a preciously mechanical properties, increased in average 45% in comparison with hand lay up method. The scanning electronic microscopy has been used for investigation on void appearance of composite materials.

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  • Tham khảo sách 'electroactive polymers for robotic applications kwang j. kim and satoshi tadokoro', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả

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  • Polymer blends containing nylon-6 and polypropylene (PP) were prepared by using a single screw extruder. Three different types of maleic anhydride modified PP (PPMA06, PPMA1and PPMA05) were used as compabilizers to examine their effects. The properties included tensile strength, Izod impact strength, torque rheometry and extent of water absorption of the resulting blends were measured and the morphology was characterized by using scanning electron microscope (SEM). The crystallization behavior of blends was analyzed by monitoring differential scanning calorimetry (DSC), X-ray diffraction.

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  • Although bamboo fibers have well mechanical properties but they are brittle caused impossibility to make fabric like jute of flax fibers. Two kinds of bamboo fibers, having industrial application are short fiber and long fiber for making mat. Polypropylene (PP)-short bamboo fiber composites have been carried out research systematically in Polymer Centre of Hanoi University.

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  • The general review of influence of the pollutants on polymers has been presented by Jellinek et al. [1]. Therein the characterization of reactivity of polymeric materials toward aggressive gases is given. The various polymers were used as films of 20 μ thickness. The thickness is enough small to exclude in most cases the diffusion as the determining factor of the pollutant action. The films were investigated under different conditions: 1) the pollutant action; 2) the oxygen action; 3) UV light action; 4) UV light and oxygen; 5) UV light, oxygen and pollutants.

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  • This paper presents the result of research on equipment development of vacuum injection molding technique for preparation the chopped bamboo fiber polymer composite and some properties of obtained composite material. For the vacuum injection molding technique, firstly the dry fibers were plated in the mold. Then the mold was closed by the vacuum bag, the air inside the mold was sucked out by a vacuum pump, due to the difference of the pressure in side and outside the mold, the polymer liquid was transferred to the closed mold and impregnated the bamboo fiber.

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  • The electrooxidation of 5-hydroxy-1,4-naphthoquinone (JUG) in organic media leads to conducting polymer film on glassy and Pt electrodes. The IR ex situ, IR in situ (MIRFTIRS) during the film formation, XPS studies indicate that electropolymerization occurs via the OH group while quinone group on the other ring remains intact and shows a very good electro activity and stability in different media, particularly in aqueous, biocompatible one.

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  • Polyethylene-starch blend polymer has already found to be a potential candidate to replace non-degradable plastic in packaging [7]. However, the degradation of that polymer in natural ambience (soil burial test) needs to be further evaluated. The purpose of this study is to investigate the degradability of PE-starch blend polymer in soil and in liquid medium. The soil is added starch degrading bacteria isolated from natural soil.

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  • Polymers present a class of materials that play a role of importance growing in catalysis. Polymeric catalysts based on polypropylene-polyacrylic acid (PP-APA) were prepared by the two methods: co-polymerization in the presence of transition metal ions (Cu(II), Fe(III), Co(II), Mn(II)…) and soaking method. Their catalytic activity was determined by oxidation reactions of ions S2- and hydroquinone by molecular oxygen in normal condition.

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