Abstract:

The alloys of polyethylene terephthalate(PET)/styrene ethylene butylene styrene(SEBS)/trimethylol propane trimethylacrylate(TMPTA) and PET/SEBS-g-MAH(maleic anhydride)/TMPTA were prepared by melting blending with a twinscrew extruder and irradiated by a Co-60 source. The effects of irradiation on the structure and properties of blends were studied through characterizations of mechanical properties, phase morphology and gel content analysis. The results of scanning electron microscopy(SEM) and gel extraction indicated that irradiation effectively improved the compatibility of PET/SEBS blends in the presence of an appropriate amount of TMPTA, which was ascribed to the generation of a new copolymer comprising both chains of SEBS and PET at the interface area. The compatibility was confirmed by the changes of impact strength as well. When the mass fraction of SEBS and TMPTA were 20% and 1% respectively, the impact strength of the blend reached 17.3 kJ/m2 after irradiation at 50 kGy. The introduction of maleic anhydride groups to SEBS chains did not change the phase structure obviously, but the maximum of impact strength was only 11.5 kJ/m2 in this case, significantly lower than that of the blends without maleic anhydride groups.

Key words: Polyethylene terephthalate (PET), blending, irradiation, compatibilization, toughness