MODIFICATION OF CRYSTALLIZATION PROPERTIES OF POLY(ETHYLENE TEREPHTHALATE) BY COPOLYMERIZATION WITH ARYLATE UNITS .1. PREPARATION AND ISOTHERMAL CRYSTALLIZATION OF 4,4'-BIPHENOL-CONTAINING COPOLYMERS

摘要

Crystallization properties of the copolymers of poly(ethylene terephthalate) (PET) comprised of a small amount of 4,4'-biphenol units were compared by isothermal crystallization with the time-resolved light scattering method. These copolyesters were prepared from PET, terephthalic acid, and 4,4'-biphenol diacetate by acidolysis reaction and following polycondensation. The copolymer with 2 mol % of 4,4'-biphenol had a crystallization characteristic similar to that of PET with a decreased crystallization rate. On the other hand, the copolymers containing 4 and 8 mol % of 4,4'-biphenol showed enhanced crystal nucleation, and the 8 mol % copolymer had a crystallization rate of ca. twice as fast as that of PET. In these systems, wide-angle X-ray diffraction peaks of the crystal which appeared with crystallization were similar to those of PET, though another ordered domain was observed in the 8 mol % copolymer, which seems to have no direct influence on the crystallization and melting cycle. [References: 12]