Modification of the thermal properties and crystallization behaviour of poly(ethylene terephthalate) by copolymerization

Abstract

Poly(ethylene terephthalate) (PET) is a widely used polyester, which can be crystallized from the melt over a wide range of supercooling conditions or, alternatively, quenched into the amorphous state and, subsequently, crystallized by thermal treatment above the glass‐transition temperature. It is well known that the crystallization of PET can be hindered by means of copolymerization or reactive blending. The incorporation of comonomeric units into the polymer backbone leads to an irregular chain structure and thereby inhibits regular chain packing for crystallization. The crystallization of PET copolyesters is strongly influenced by the chain microstructure regarding comonomer distribution, randomness and length of the crystallizable ethylene terephthalate sequences. This paper is mainly devoted to the thermally induced crystallization behaviour of PET and to reviewing the efforts that have been made in the last decade to modify the glass‐transition and melting temperatures, the crystallinity and the crystallization rate of this polyester. Furthermore, some illustrative experimental data obtained from isothermal and non‐isothermal crystallization of PET are included in this study.© 2003 Society of Chemical Industry

Poly(ethylene terephthalate) (PET) degradation during the Zn catalysed transesterification with dibutyl maleate functionalized polyolefins

“…But in this case secondary crystallization prevails. Hence the shape differences in the thermograms can be attributed to the enhancement of the primary crystallization for the PETN2d, the melting peak of which is reported to be at higher temperature [34] (Fig. 3).…”

Rheological Features and Flow‐Induced Crystallization of Branched Poly[ethylene‐co‐(1,4‐cyclohexanedimethylene terephthalate)] Copolyesters

“…[5] Poly(ethylene terephthalate) copolymers in which about 30 mol-% of EG is replaced by 1,4-cyclohexane dimethanol (CHDM) have been recently developed to cover applications where low crystallinity and high glass transition temperature (T g ) are a priority. [6][7][8] These CHDM containing copolyesters poly[ethylene-co-(1,4-cyclohexanedimethylene terephthalate)] (PECT) are usually produced by copolymerization of PTA or dimethyl terephthalate A set of amorphous poly[ethylene-co-(1,4-cyclohexanedimethylene terephthalate)] (PECT) copolymers containing 25 and 30% of 1,4-cyclohexane dimethylene (CHDM) units and small amounts of branching agent pentaerythritol (PER) is investigated. The level of long chain branching was estimated by analyzing the positive deviation from h 0M 3:54 w law.…”

A small-angle X-ray scattering study of the effect of chain architecture on the shear-induced crystallization of branched and linear poly(ethylene terephthalate)

“…Previous studies of the branching of PET have shown branching to affect the crystallization kinetics resulting in both more rapid crystallization and slower crystallization (Bikiaris & Karayannidis, 2003;Jayakannan & Ramakrishnan, 1999;Kint & Munoz-Guerra, 2003;Rosu et al, 1997;Rosu et al, 1999;Scheirs & Long, 2003). It seems that knowledge of branching alone is not sufficient to predict the crystallization kinetics.…”