Rheological and thermogravimetric analysis of unmodified and modified aliphatic hyperbranched polyester

The influence of the type of end groups on the rheological and thermal properties of aliphatic hyperbranched polyesters (AHBP) was investigated in this work. Unmodified, hydroxy-functional AHBP sample of third pseudo generation (AHBP-3) and the same sample whose end –OH groups were modified with stearic acid (AHBP-3SA) were examined. The presence of the long alkyl chain ends, instead of the polar –OH groups, has reduced the possibility for H-bonding and value of the glass transition temperature. On the other side, by modification of the end –OH groups with stearic acid, thermal stability of AHBP has been improved