Research Progress on Modifications of Crystallization Behaviors of Polyethylene Terephthalate
Based on the crystallization behaviors of polyethylene terephthalate(PET),the research progresses in the field of PET crystallization behavior modification at home and abroad were introduced in this paper,mainly involving the copolymerization modification,blending modification,chain expansion reaction modification,processing condition modification,and various synergistic modifications.Among them,copolymerization modification could change the regularity of PET molecular chains through the introduction of flexible chain segments to make its aggregation structures more stable,but the complexity of its preparation processes limits its applications in practical production.The blending modification could improve the crystallization behaviors of PET through the heterogeneous nucleation,but its poor compatibility with PET interface still has some limitations to the modification.PET modified by chain extension reactions has excellent crystallization properties,but it might have adverse effects on mechanical properties.Although the modification of processing conditions does not bring the addition of additional chemicals,the changes in the macro-properties limit the application ranges of PET.The crystallization properties of PET have been improved by various synergistic modifications through complementary advantages,but the complex action mechanisms remain to be clarified.Finally,the problems existing in the applications and developments of PET modification methods and modifiers were pointed out,and the development directions of optimizing PET special additives were prospected.