Blends of polybutyleneterephthalate with ethylene-propylene elastomer containing isocyanate functional group

Ethylene-propylene elastomer (EPM) grafted with an isocyanate-containing mo nomer (HT) was blended with polybutyleneterephthalate (PBT), and its morpho logical, rheological, and mechanical properties were studied. The monomer H I was prepared by the reaction of 2-hydroxylethylnlethacrylate and isophoro ne diisocyanate. The HI was successfully incorporated onto EPM backbone thr ough solution graft reaction with radical initiator. When the PET was blend ed with HI-grafted EPM (EHI), the morphologies of the dispersed phase displ ayed differences with respect to particle size and interfacial adhesion, wh en compared with those of the PBT/EPM blend. The increase in complex viscos ity, storage modulus and impact strength of PBT/EHI blends ensured that the compatibility between PET and EPM was improved through functionalization o f EPM with the isocyanate moiety. These results are mainly due to in situ g raft PBT-EPM copolymer that formed through the chemical reaction between th e isocyanate group of EHI and hydroxyl or carboxyl end groups of PET. (C) 2 001 Elsevier Science Ltd. All rights reserved.