Effect of poly(ethylene glycol) on the solid-state polymerization of poly(ethylene tereplithalate)

Poly(ethylene glycol) (PEG) and end-capped poly(ethylene glycol) (poly(ethylene glycol) dimethyl ether (PEGDME)) of number average molecular weight 1000 g mol(-1) was melt blended with poly(ethylene terephthalate) (PET) oligomer. NMR, DSC and WAXS techniques characterized the structure and morphology of the blends. Both these samples show reduction in T-g and similar crystallization behavior. Solid-state polymerization (SSP) was performed on these blend samples using Sb2O3 as catalyst under reduced pressure at temperatures below the melting point of the samples. Inherent viscosity data indicate that for the blend sample with PEG there is enhancement of SSP rate, while for the sample with PEGDME the SSP rate is suppressed. NMR data showed that PEG is incorporated into the PET chain, while PEGDME does not react with PET. (C) 2005 Society of Chemical Industry.