POLYARYLENEETHERKETONES OBTAINING WITH REACTION OF NUCLEOPHILIC SUBSTITUTION

Abstract

The article deals with the study of influence of the synthesis conditions on the molecular weight of polyaryleneetherketones (PAEK), received with nucleophilic substitution reaction of activated aryl halide. The synthesis of PAEK with the nucleophilic substitution reaction carried out as partially hydrolyzed homopolycondensation of phenolates and aromatic dihalides containing a carbonyl group in the molecule and derivatives of polycondensation of aromatic bisphenols with activated aromatic dihalides, and aromatic nitro compounds. The nucleophilic substitution of halogen in aryldihalogens proceeds through formation of Meisenheimer complex, where the negative charge of the electron-electron ring stabilizes the group. The high efficiency of the synthesis of PAEK with nucleophilic substitution reaction is mainly determined with several factors, the main of which are: 1) the structure of the starting monomers; 2) the nature of the solvent; 3) the nature of phenolate; 4) side reactions. For these materials it was revealed that the ratio of nucleophilic and electrophilic reagents has pronounced effect on the molecular weight of the obtained polymer, without affecting the poly dispersion. PAEK synthesis processes are optimized by controlling the replacement of some of the monomers, the temperature and concentration of reactants change. It was shown that the polyarylene ether ketones and copolymers have a high thermal heat resistance, mechanical properties. They show considerable heat resistance in air, capable of forming a transparent film and melts. Thus, data of literature review show that the nucleophilic substitution reaction is promising for PAEK synthesis of various chemical structures and produces polymers having valuable properties.