The Effect of Block Copolymer and its Ionomer on the Crystallization Behaviour of Poly(ethylene terephthalate

Poly (ethylene terephthalate) (PET) was blended with poly (styrene-b-tertiary butyl acrylate) (P(St-b-tBA)) and poly(styrene-b-acrylic K+) (P(St-b-AK+)) ionomer with level of block copolymer varying between 2 and 10 wt% which were prepared by atom transfer radical polymerization (ATRP). All the samples were prepared by the solution blending in phenol/tetrachloroethane (60/40 percent by weight) as solvent at SO°C. The crystallization and melting behaviour of the sample were then studied by differential scanning calorimetry (DSC). The result showed that crystallization rate of PET was accelerated by the block copolymer as well as by its ionomer which was similar to that of a nucleating agent. The acceleration of PET crystallization rate was more pronounced by the increasing level of block copolymer. The melting temperature observed from the DSC analysis showed perturbation of crystal growth as reflected by the broadening of the melting endotherm and lowering of melting temperatures due to the presence of the specific interactions