Research On Chain Extension And Toughening Of Polyethylene Terephthalate(PET)

In this paper,the functionalized elastomer POE with different GMA grafting amounts were prepared by the method of melt grafting.The elastomer was blended with PET,the effects of GMA grafting amount and elastomer content on the structure and properties of the PET blends were investigated;three chain extenders with different amounts of GMA copolymerization were introduced into it,and the the influence of chain extenders on the structure and properties of PET blends.The result showed that:Successfully melt-grafted GMA with different contents on POE;POE with less than 1%GMA grafting amount could not toughen PET,and POE with more than 2% GMA grafting amount could effectively toughen PET.When there were more,the brittle-ductile transition occurred in advance.It showed that POE can effectively toughen PET by GMA grafting,and the grafting dosage had a greater impact on the toughening effects.The addition of elastomer would reduce the tensile strength,elastic modulus and bending strength of the PET blends.(2)POE grafted with 3% GMA was introduced into the PET/POE blends to replace part of the pure POE,and the effects of the introduction of functionalized POE on the performance of the PET/POE blends were investigated.The results showed that with the increase in the amount of functionalized POE,POE can be better dispersed in the PET matrix and more refined,the compatibility of the two were improved,when the proportion reached 60%,The notched impact strength of the PET blends reached 600J/m,could toughen PET effectively.(3)The chain extender PMMA-co-GMA was introduced into PET,and the influence of the type and amount of chain extender on the toughening process of PET was investigated.The results found that when the amount of chain extender increased,or the copolymer content in the chain extender increased at the same amount,the brittle-to-ductile transition of the blends was slightly delayed.When the amount of chain extender or copolymer content increased,the blending strength increased,and the tensile strength and modulus of elasticity decreased.In general,the amount of chain extender and the copolymer content had little effect on the performance of the blend.