Polymer Science, Series C最新文献

The possibilities of using special rheological properties of polymers in the petrochemical industry, in particular, at the stage of oil production in the modification of drilling fluids and oil displacement, the transportation of oil in pipeline systems, and the modification of properties of main hydrocarbon products are considered. In all the cases, polymers with different compositions and structures are used as modifiers of the rheological properties of process fluids based on water or hydrocarbons. In addition to the control of the viscosity characteristics of these fluids, polymers promote the manifestation of elasticity of the solutions created which may play a significant role in optimizing the process. The aspects of the use of polymers for decreasing the hydrodynamic resistance during the pumping of oil in trunk pipelines are discussed in most detail. When discussing options of the application of polymers special attention is paid to the related environmental problems.

The transition to green chemistry and biodegradable polymers is a logical stage in the development of modern chemical science and technology. In the framework of this review, the advantages, disadvantages, and potential of biodegradable polymers of synthetic and natural origin are compared using the example of polylactide and chitosan as traditional representatives of these classes of polymers, and the possibilities of their combination via obtaining composite materials or copolymers are assessed. The mechanochemical approach to the synthesis of graft copolymers of chitosan with oligolactides/polylactides is considered in more detail.

Evolution of the morphology of cellulose solutions in N-methylmorpholine-N-oxide during coagulation with a “soft” coagulant, isobutyl alcohol, at different temperatures is considered. Using optical interferometry and transmitted and scanning electron microscopy the mechanism of phase separation of the system to form a polymer phase is studied depending on the temperature of alcohol. It is shown that, in the case of a room temperature coagulant, a heterogeneous film with a droplet texture enlarging over thickness appears along the precipitation front. At a high temperature of alcohol the coagulation of the solution occurs in two stages. At the first stage the penetration of the coagulant into the jet of spinning solution leading to the formation of vacuoles occurs. The phase separation of the solution proceeds within the vacuoles as microreactors to form a polymer-concentrated shell and a polymer-diluted phase in the vacuole cavity. At the second stage the coagulant diffuses through the vacuole shell into the bulk of the solution and causes its uniform coagulation. The process of vacuole formation is visualized. The transverse cleavage of the film is analyzed by energy dispersive X-ray spectroscopy. The difference in the content of C, N, and O atoms on the walls of vacuoles and in the region of a film with a uniform cellular morphology is established.

The review discusses the application of polymers for the control of soil degradation caused by wind and water erosion. The background of the problem, current situation with the soil erosion in the world and Russian Federation, traditional methods for controlling erosion processes, and natural and synthetic soil amendments (soil conditioners) are described. Particular attention is paid to t traditional conditioners, polyacrylamide and its derivatives as well as conditioners obtained from interpolyelectrolyte complexes, the products of interaction of oppositely charged ionic polymers. The results of the laboratory experiments, field tests, and practical application of the conditioners are presented. A new type of soil conditioners based on interpolyelectrolyte complexes is described in detail, and the prospects of their application in antierosion technologies are considered.

The needs of modern surgery triggered the intensive development of transplantology, medical materials science, and tissue engineering. These directions require the use of innovative materials, among which porous polymers occupy one of the leading positions. The use of natural and synthetic polymers makes it possible to adjust the structure and combination of properties of a material to its particular application. This review generalizes and systematizes the results of recent studies describing requirements imposed on the structure and properties of synthetic (or artificial) porous polymer materials and implants on their basis and the advantages and limitations of synthesis methods. The most extensively employed, promising initial materials are considered, and the possible areas of application of polymer implants based on these materials are highlighted.

This review focuses on the processes involved in producing heat-resistant matrices for fiber reinforced plastics (FRP) by polymerization of the resins consisting of phthalonitrile monomers and comonomers, and the specifics of fiber reinforced plastics fabrication technologies. Polymerization behaviors observed in the presence of various types of initiators and in different temperature modes are reviewed. Fabrication methods and mechanical properties of FRPs based on phthalonitrile resins with various reinforcing materials are discussed. Properties of glass fiber reinforced plastics (GFRP) and carbon fiber reinforced plastics (CFRP) obtained through curing of different phthalonitriles are compared.

This review summarizes our and published data on the kinetics and mechanism of controlled radical polymerization of methacrylates mediated by nitroxide radicals. The reasons influencing the possibility or impossibility of the realization of radical polymerization of methyl methacrylate in the mode of reversible inhibition are analyzed. The main factors determining the specificity of the nitroxide-mediated polymerization of methacrylates are the interaction of nitroxides with growing radicals by the disproportionation mechanism, the Fischer hypereffect, a high rate of reinitiation, and an abnormally low rate of reversible termination.

Global production of synthetic polymers such as plastics is nearly 390 million tons/year, which is creating enormous challenges on a number of frontiers including environment, sustainable development and health. The non-degradability of plastics and petrochemical-based polymers is a huge environmental crisis despite being an industry with billions of dollars share in global economy. Water pollution due to synthetic plastics and related products is evident from the fact that 7 million tons of land based plastic debris enters oceans and water bodies annually endangering the sea life which is not only a concern for the aquatic environment but also for the sea food industry and eventually to human health. Eco-friendly and sustainable polymers from a number of living organisms can be used as an alternative to synthetic polymers. Biopolymers such as starch, cellulose, pectin, keratin, chitin, gelatin and polyhydroxyalkanoates can be obtained from natural biomass sources. All these biopolymers exhibit suitable physiochemical, thermal and mechanical properties that make them suitable for the production of bioplastics that are biobased and biodegradable in nature. Use of biopolymers is not limited to bioplastics but ranges from sustainable production of other products such as bio-implants, biofuels, and medicinal products. In this review, we have discussed comprehensively about the sources of biopolymers, their extraction and purification methods and the reasons that make them efficient biopolymers for the environment.

Poly(butylene adipate-co-terephthalate) is a well-known aliphatic-aromatic biodegradable random co-polyester that is structurally composed of a chemical unit of butylene adipate and butylene terephthalate. It can be synthesized by a polycondensation reaction in the melt stage. However, the synthesis process is very much complicated because it requires a high esterification temperature as well as a vacuum to achieve a suitable molecular weight for different grade industrial applications. Additionally, the synthesis process gives the various side reactions that associate depolymerization with hydrolytic degradation, the color of polymer, tetrahydrofuran formation, etc. This short literature review deals with the various methods development of poly(butylene adipate-co-terephthalate) synthesis for commercial scale. Moreover, different grades of its synthesis are also investigated with chain extenders, branching agents, chemical functionalization and in-situ incorporation of nanocomposites.

The problems that have arisen in the process of research work when solving various applied and scientific problems are considered. Basically, this concerns the synthesis and various properties of polymers. Special attention is paid to phenomena, at first glance, mysterious, requiring a nontrivial approach to explain them. Only understanding the essence of the phenomenon itself makes it possible to obtain an answer and find an adequate qualitative and quantitative description of a new mystery of nature.