Effect of linear comonomers on the rate of crystallization of copolyesters

Small amounts of dimethyl-4,4'-biphenyldicarboxylate, 2,7-dimethyl-4,5,9,10 -tetrahydropyrenedicarboxylate, and dimethyl-2,7-pyrenedicarboxylate have b een copolymerized into poly(ethylene) terephthalate (PET). The thermal tran sitions of the copolymers have been characterized, and the crystallization rates have been measured isothermally. Avrami analysis indicates that all t he copolymers crystallized at a slower rate than that of the PET homopolyme r. Addition of perylene to the copolymers containing pyrene enhanced the ra te of crystallization, which could be the consequence of stacked arene asse mblies serving as templates for crystal formation. (C) 2001 John Wiley & So ns, Inc.