Effect of multifunctional comonomers on the properties of poly(ethylene terephthalate) copolymers

Abstract

The properties of poly(ethylene terephthalate) (PET) and its copolymers containing 0.04-0.15 mol% of pentaerythritol and trimethylolethane (TME) have been investigated. The molecular weight of the copolymers increased with comonomer content, and this effect was observed significantly with pentaerythritol copolymers, resulting in broad molecular weight distribution. The comonomer effect on the mechanical properties was small. The shear viscosity of the copolymers showed shear thinning within the experimental shear rate range. The crystallization rate and birefringence of the fibres containing 0.103 mol% pentaerythritol increased with the spin draw ratio, whereas they decreased, with comonomer content. (C) 2002 Society of Chemical Industry.