Transesterification in poly(ethylene terephthalate) and poly(ethylene naphthalene 2,6-dicarboxylate) blends; the influence of hydroxyl end groups

Two samples of a single composition blend of PET and PEN were prepared by solution blending using different solvents such that the hydroxyl end groups in one blend were modified. The rate of transesterification in each blend was studied using proton NMR, an established technique for this system. The results indicate that the rate of transesterification is influenced dramatically by end group modification, providing clear evidence that hydroxyl end groups participate in the reaction mechanism. (C) 1999 Elsevier Science Ltd. All rights reserved.