SYNTHESIS AND THERMAL-BEHAVIOR OF POLY(ETHYLENE-CO-BUTYLENE NAPHTHALENE-2,6-DICARBOXYLATE)S

Poly(ethylene naphthalene-2,6-dicarboxylate) and poly(1,4-butylene nap hthalene-2,6-dicarboxylate) homopolymers were synthesized by the two-s tep melt polycondensation process of dimethyl naphthalene-2,6-dicarbox ylate and ethylene glycol (EG) or 1,4-butanediol (BD) respectively. Ei ght copolymers of the above three monomers were also synthesized by va rying the mol% of BD with respect to EG in the initial monomer feed. T he copolymer composition was determined by H-1 n.m.r. spectroscopy. Th e thermal behaviour was investigated over the entire range of copolyme r composition by differential scanning calorimetry and thermomechanica l analysis. The glass transition (T-g), cold crystallization (T-cc), m elting point (T-m) and crystallization (T-c) temperatures have been de termined. The melting temperature of the above copolymers was depresse d gradually at first with the increase of ED in the composition and eu tectic behaviour appeared with a minimum at about 40 mol% ED content. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.