Modified Fibre and Film Materials

Abstract

Some results of studies on modification of polymers and polymeric materials conducted in the Department of Chemical Fibre Technology at Moscow State Textile University are examined. The promise of using the developed methods for creating materials for special applications is demonstrated: fire-retardant, chemisorption, antiadhesive, for medicine.Chemical modification is one of the most efficient methods of deliberately altering the structure, composition, and properties of fibre and film materials. Investigating the characteristics of the chemical reactions and structural mechanisms that occur in polymer systems will allow developing principles and methods for manufacturing processes for fabrication of new high-efficiency polymeric materials.Graft polymerization reactions, which alone alter the properties of polymeric materials in a direction which is a function of the type of graft monomer, occupy a special place in such systems. In particular, the results obtained in graft polymerization of such monomers as acrylonitrile, styrene, methylvinylpyridine, dimethylamino-and hydroxyethyl methacrylate, etc., are well known. At the same time, the possibilities of using reactions of this type are not limited to the direct use of graft copolymers. They have been expanded significantly due to implementation of chemical transformations of functional groups in graft chains.As the studies have shown, the approach based on graft polymerization of nonionogenic monomers containing reactive functional groups and the subsequent chemical transformations in reacting with reagents containing ionogenic groups is of great interest for solving the problem of fabricating fibre chemisorbents. A combination of small elementary fibre cross sections with localization of ionogenic groups in the surface layers, which ensure a high rate of sorption processes, is primary for materials of this type.The studies in [1-4] concerned chemical transformations of graft copolymers, where such polymers as polycaproamide, polyvinyl alcohol, cellulose, and glycidyl methacrylate modified by graft polymerization played the role of the matrix polymer. The presence of reactive oxirane (epoxide) groups in polyglycidyl methacrylate (PGMA) graft chains was grounds for using nitrogen-containing compounds of different structure (hydroxyethylamine, hydrazine and its derivatives, and many acid hydrazides) as nucleophilic reagents.The results of the studies showed that the reactivity of nitrogen-containing nucleophilic reagents is determined by many factors. They include: the diffusion characteristics of the process related to a change in the degree of swelling of the graft component and in some cases also the polymer matrix; such a change increases the diffusion coefficient of the reagent by almost a decimal order of magnitude in substitution of the solvent type (substitution of water by dimethylsulfoxide in the reaction with hydrazine hydrate); the initial reaction rate changes similarly; the change in the nucleophilicity of the reagents as a result of their reactio...

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