抄録
In this study, the mechanical properties and morphological change of polyethylene terephthalate (PET)/medium density polyethylene (MDPE) blends with/without compatibilizers were investigated upon heat-treatment cycling. The compatibilizer, which consists of ethylene-glycidyl methacrylate (EGMA) as a main chain, showed the good mechanical properties. For example, PET/MDPE with EGMA compatibilizer blend had the higher elongation at breaking (～800%) in comparison with the PET/MDPE without compatibilizer (neat PET/MDPE). Although the value of the elongation at break of PET/MDPE with/without EGMA compatibilizer decreased upon heat-treatment cycling, the PET/MDPE with 3wt%～5wt% EGMA compatibilizer still showed the high elongation at break at the second heat-treatment cycle and after the third cycle. This result shows the possibility that the material recycling concerning PET, which is recycled mainly one time, can be substantially done two times or more, and an increase of the heat-treatment cycling number means that the gross weight of present PET waste and PE waste can be greatly decreased. In order to compare the morphological change of the PET/MDPE with/without compatibilizer, scanning electron microscope observation was carried out. As a result, when adding the EGMA compatibilizer into the PET/MDPE, the size of the PE phase was smaller than that of neat PET/MDPE. Moreover, after several heat-treatment cycles, the morphological change was not be observed for the PET/MDPE with EGMA compatibilizer. From these results, it would be deduced that EGMA can react with the end-groups of PET during heat-treatment, so that the mechanical properties and morphological change of PET/PE composites can not be observed.
