THERMOTROPIC ELASTOMERS WITH POLY(OXY-1,4-BUTANEDIYL) UNITS IN THE MAIN-CHAIN

The paper describes the synthesis of thermotropic elastomers from trim ellitimide-terminated poly(oxy-1,4-butanediyl) [synonyms: poly(tetrame thylene ether glycol), PTMG; poly(tetrahydrofuran), poly(THF)] and ace toxy group-terminated rigid blocks. Copolyester imides are formed by t ransesterification polycondensation in the melt. According to C-13 NMR investigations, their chain sequence distribution is characterized by a block-like structure in which the preformed rigid units are partial ly exchanged by transesterification reactions during the melt polycond ensation. The degree of transesterification depends on the reaction ti me. The influence of the length of the flexible PTMG units and of the concentration of rigid units on the phase behaviour as well as on the thermal behaviour and the dynamic-mechanical behaviour of the block co polymers is discussed with respect to aromatic model compounds.