Thermal analysis of poly(desamino arylates)

The goal of this study is to better understand the thermal characteristics and molecular behavior of two poly(desaminotyrosyl arylates). TGA, DSC and TSPC studies were conducted on poly(12,10) and poly(2,2) after the samples were exposed to various conditions. The TGA of poly(12,10) shows low water uptake at 25C, higher water uptake at 80C. Water uptake for poly(2,2) at 25C is similar to poly(12,10) at 80C. The thermally stimulated polarization current (TSPC) results indicate a Tg for poly(2,2) at 80C and for poly(12,10) at 40C. DSC and TSPC studies suggest that poly(12,10) has two distinct modes of non-crystalline organization with a transition between these modes at about 60C. The mode above 60C has the higher water uptake. Annealing at 70C for 20 hours favors the high temperature mode. At room temperature, the material will relax to the low temperature mode. Previously published results indicate that these two modes of non-crystalline organization represent two different modes of hydrogen bonding.