Abstract: Poly(ethylene terephthalate) (CEPET) was chain extended with pyromelliticdianhydride (PMDA), which was foamed by batch method using CO2 as a foaming agent. Rheological behavior and cellular structure of CEPET foam were analyzed by rotational rheometer and scanning electron microscope. It showed that the storage modulus of CEPET was increased with increasing PMDA dosage, and the loss factor changed in an opposite way. The introduction of PMDA improved the melt strength and cellular morphology of neat PET. The expansion ratio of CEPET foam with a PMDA content of 1.0 phr was 32.55.

Key words: poly (ethylene terephthalate), pyromellitic dianhydride, chain extender, rheology behavior, foaming