Modifying thermal properties of polyesters by incorporating additional groups

Sustainable polyesters are promising materials to replace petroleum-based non-degradable polymers. Unfortunately, the high crystallinity degree of some polyesters limits their applications due to poor mechanical properties and low melting temperatures. A suitable strategy to broaden their applications is introducing functional groups into their backbone to enhance intermolecular interactions which can impact the thermal properties of the material. Nevertheless, a comprehensive understanding of these interactions on the crystallization properties is still lacking. In this work, we have studied the impact of incorporating additional ester and amide groups into aliphatic polyesters with varying numbers of methylene groups between the functional groups. We show that functional groups that induce strong intermolecular interactions increase the melting and crystallization temperature. However, these groups slow down the crystallization kinetics. This work demonstrates how appropriately selecting the functional groups makes it possible to independently tune the thermal transition and the crystallization kinetics of the promising polyesters.