Transesterification kinetics of poly(ethylene terephthalate) and poly(ethylene 2,6-naphthalate) blends with the addition of 2,2 '-bis(1,3-oxazoline)

The kinetics of the trans esterification reaction between poly(ethylene ter ephthalate) (PET) and poly(ethylene 2,6-naphthalate) (PEN) with and without the addition of a chain extender were studied with H-1 NMR. Different kine tic approaches were considered, and a second-order, reversible reaction was accepted for the PET/PEN reactive blend system. The addition of 2,2'-bis(1 ,3-oxazoline) (BOZ) promoted the transesterification reaction between PET a nd PEN in the molten state. The activation energy of the transesterificatio n reaction for the PET/PEN reactive blend with BOZ (94.0 kJ/mol) was lower than that without BOZ (168.9KJ/mol). The rate constant k took an almost con stant value for blend samples with different compositions mixed at 275 degr eesC. (C) 2001 John Wiley & Sons, Inc.