Effect of chain extender combination modification on PET properties

The reactive extrusion modification of polyethylene terephthalate (PET) was carried out by coupling 1,3-phenylene-bis-oxazoline (PBO) and pyromelliticdianhydride (PMDA), and the effects of the chain expansion modification of the PET were analyzed for varying ratios of the two chain expanders. The changes in torque were monitored with a torque rheometer during the chain expansion reaction supported by dynamic rheological tests, crystallization property tests and mechanical property tests. The effects of chain expansion modification on the molecular chain structure and mechanical properties of PET were analyzed. The results show that the maximum impact strength of a PBO/PMDA-modified PET spline is 73.42 kJ/m², which is 103.1% higher than that of PMDA-modified PET. The results provide a valuable reference for the preparation of new industrialized foams by extrusion modification of PET.