Block copolymers with poly(tetramethylene glycol) (PTMG) spacers of different length and the 4,4'-(terephthaloyldioxy) dibenzoyl unit have been synthesized by high temperature solution polycondensation. The influence of the spacer length on thermal behaviour and solid phase structure of alternating polyesters in comparison with pure PTMG has been determined by d.s.c, and WAXS investigations. Up to spacer molecular weights of 650 g mol- 1 (degree of polymerization, DP ~ 9), polymers with thermotropic liquid crystalline phase behaviour are obtained. Above spacer molecular weights of 1000 g mo1-1 (DP~ 14), the coexistence of two crystalline phases resulting in polymers with block-like character is discussed.
Посилання на статтю:
Thermotropic block copolymers: polyesters with flexible poly(tetramethylene glycol) units in the main chain / Kerstin Mitrach, Doris Pospiech, Liane Hiiu&ler, Dieter Voigt,Dieter Jehnichen* and ianfred Riitzsch // Polymer. – 1993. – Vol 34. – P. 3469-3474.