Modified polymeric materials, some fundamental and applied aspects

Abstract

Results of theoretical and applied studies on the modification of fibrous and film materials that were performed in the Department of Chemical Fiber and Nanomaterial Technology during recent years were presented.Controlled regulation of the properties of complex polymeric systems using various methods to modify them during the synthesis of the fiber-forming polymers and the production of shaped composites and to change the functional composition and structure of the formed fibers and materials based on them occupied an important place in the wide ranging scientific interests of Kirill Evgen'evich Pererpelkin that encompassed problems of the theory and technology of chemical fiber formation processes and the structures and properties of composites. The present article reviews results of research in this area that was carried out in the Department of Chemical Fibers and Nanomaterials of A. N. Kosygin Moscow State Textile University and is dedicated to the memory and honor of K. E. Perepelkin, our colleague and friend.Many effective methods for making controlled changes in the structures and properties of polymers are based on their chemical modification. Studying trends in chemical reactions and the influence of subtle structural features of macromolecules and the supramolecular structure on the physical and physicochemical properties of polymeric systems is one of the most important problems of polymer chemistry. Its solution not only enables the development and deepening of fundamental knowledge but also acts as a basis for elaborating methods and technical processes for producing new high-efficiency polymers.Graft polymerization of ionizable and non-ionizable monomers containing reactive functional groups and their subsequent chemical transformations occupy a special place in the study of polymeric systems. These types of reactions can produce modified fibers with a broad spectrum of properties and good retention of the physicomechanical properties owing to the high strength of the industrial samples, i.e., fiber precursors, and the high technology of the process.Special attention in the evolution of this area was paid to the development of effective redox systems (RSs) that provide a high degree of conversion and efficiency of graft polymerization. A series of RSs that could carry out graft polymerization of ionizable monomers with 70-90% conversion and grafting efficiency 90-95% and of non-ionizable ones, up to 98 and 100%, respectively, was proposed [1]. The addition of small quantities of nano-sized RS components, i.e., redox-active metal ions, could accelerate substantially the formation of the macroradicals.Several process features were identified during a study of graft polymerization to polymers oriented at the interface of solid and liquid phases. The structural and physical properties (orientation and degree of crystallinity) and the dynamics of the polymer molecule as a solid body were observed to have an influence on the kinetics of radical graft polymerization. Concepts about the role of the gel eff...