Solid-phase thermal polymerization of macrocyclic ethylene terephthalate dimer using various transesterification catalysts

Thermal ring-opening polymerization of a uniform macrocyclic ethylene terep hthalate dimer with and without catalyst was investigated for the first tim e. Although polymerization progressed without a catalyst, the reaction was extremely slow and all the products were colored. Various transesterificati on catalysts were tested for their activity toward this ring-opening polyme rization. Among the various catalysts, 1,3-dichloro-1,1,3,3-tetrabutyldista nnoxane exhibited the highest catalytic activity, and a colorless polymer w ith a weight-average molecular weight of 36,100 was obtained in 100% yield by heating for 3 min at 200 degrees C. It is noteworthy that our method doe s not need a vacuum because no side products are formed during the process. (C) 2000 John Wiley & Sons, Inc.