The role of intermolecular interactions on melt memory and thermal fractionation of semicrystalline polymers

J Chem Phys. 2022 Apr 14;156(14):144902. doi: 10.1063/5.0087782.

Abstract

The origin of melt memory effects associated with semicrystalline polymers and the physical parameters involved in this process have been widely studied in the literature. However, a comprehensive understanding of the role of intermolecular interactions on melt memory is still being developed. For this purpose, we have considered aliphatic polyesters and we have incorporated amide and additional ester groups. Inserting these additional functional groups, the strength of the intermolecular interactions increases widening the melt memory effect. Not only the presence of the functional groups but also the position of these groups in the repeating unit plays a role in the melt memory effect as it impacts the strength of the intermolecular interactions in the crystals. The study of the effect of intermolecular interactions has been extended to successive self-nucleation and annealing thermal fractionation experiments to explore for the first time the role of intermolecular forces on the fractionation capacity of linear polymers. We demonstrated that intermolecular interactions act as intrinsic defects interrupting the crystallizable chain length, thus facilitating thermal fractionation. Overall, this work sheds light on the role of intermolecular interactions on the crystallization behavior of a series of aliphatic polyesters.