Two series of novel t-butyl-substituted copolyesters, poly(3-t-butyl-4-oxybenzoate-co-4-oxybenzoate)s and poly(3,5-di-t-butyl-4-oxybenzoate-co-4-oxybenzoate)s, have been synthesized. The former were prepared by the conventional transesterification reaction via an acetolysis route and the latter were made from or via a novel monomer, 3,5-di-t-butyl-4-hydroxybenzoyl chloride. These polymers were characterized by solution viscometry, infra-red spectroscopy, wide angle X-ray scattering, hot-stage polarizing microscopy and thermal analysis (d.s.c., t.g.a, and t.m.a.). Both poly(3-t-butyl-4-oxybenzoate) and poly(3,5-di-t-butyl-4-oxybenzoate) were semicrystalline and did not melt before decomposing, although they were easily soluble in conventional solvents. Of the monosubstituted copolymers, only the 50:50 composition melted at a temperature substantially below decomposition, forming a nematic mesophase, which makes this copolymer the most promising for processing. None of the disubstituted copolymers melted below its decomposition temperature
Посилання на статтю:
Thermotropic polyesters: synthesis and properties of t-butyl-substituted poly(4-oxybenzoate)s / V. Kalyvas, Z. G. Li, J. E. Mclntyre*, A. H. Milburn, J. G. Tomka andA. M. Voice // Polymer. – 1993. – Vol 34. – P. 3076-3082.