Abstract: The chain extension of recycled PET flake was studied via reactive extrusion using diisocyanatotoluene (TDI), antimony trioxide (Sb2O3), phthalic anhydride, pyromellitic dianhydrde (PMDA), and naphthalenetetra carboxylic dianhydride (NTDA) as chain extenders. It was found that effect of TDI, Sb2O3, phthalic anhydride, and NTDA was weak, while PMDA could increase the intrinsic viscosity of the material obviously. A mixture of PMDA and phthalic anhydride provided the best chain extension. The intrinsic viscosity of the material reached 0.96 dL/g when the content of PMDA and phthalic anhydride was 0.3 % and 0.2 %, respectively.

Key words: recycled flake, poly(ethylene terephthalate), reactive extrusion, chain extender, intrinsic viscosity