On the synthesis of polyphenylene sulfide and copolymers based on it by the reaction of nonequilibrium polycondensation

Abstract

Polyphenylene sulfide is a semicrystalline engineering thermoplastic, in the world market of superconstructive materials is presented in two modifications: the first is a cross-linked material, the second is a linear polymer with a highly ordered supramolecular structure.Polyphenylene sulfides, synthesized according to the classical procedure in N-methyl-2-pyrrolidone, are characterized by low molecular weight characteristics due to the occurrence of side reactions. The main yield of the target product does not exceed 45%, even with an increase in the synthesis time of up to 120 hours.Polymers with higher viscosity characteristics can be obtained by heat treatment of synthesized polyphenylene sulfide at 240-260 °С. Copolymers with new monomeric fragments, such as sulfonic, ketone, amide, imide, etc., have been synthesized, which lead to amorphous polymers. The copolymers obtained are well soluble at room temperature and have a higher yield and a molecular weight. The introduction of cyclic groups into the macromolecule of polyphenylene sulfide results in an increase in heat resistance (500 °C) and solubility. Over the past 10-15 years, special attention has been paid to the synthesis of macrocyclic oligomers, which are used subsequently for the preparation of high molecular copolymers by a ring-opening polymerization reaction. This technique allows to obtain polymers in a short time and without the formation of by-products.During the synthesis of copolymers, extensive knowledge of the effect of the chemical structure on the performance properties of materials was obtained, and new methods were developed that reduced the possibility of percolation reactions. Thus, the synthesis of new polyheteroarylenes becomes topical, the review reflects the results of research over the past few years on the development on their basis of materials with unique valuable properties.