| Abstract: | Polyethylene terephthalate (PET) was blended with two kinds of copoly(ethylene terephthalate-p-oxybenzoate)] (POB–PET) copolyester, designated as P46 and P64, respectively. The PET and POB–PET copolyester were combined in the ratios of 85/15, 70/30, and 50/50. The blends were melt mixed in a Brabender Plasticorder at 275, 285, and 293°C for different amounts of time. The transesterification reactions during the melt mixing processes of PET with POB–PET copolyester blends were detected by proton nuclear magnetic resonance analysis. The values of the rate constants are a function of temperature and the composition of blends. The transesterification reactions that may occur during the melt mixing processes have been discussed also. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 2727–2732, 1999 |
