Structure of poly(hexamethylene sebacate)

The crystalline structure of poly(hexamethylene sebacate) has been studied using transmission electron microscopy and X-ray diffraction. Molecular chains adopt a slightly distorted all-trans conformation and pack in a Monoclinic unit cell with space group P121/n1. The unit cell contains two chain segments, with a chain setting angle similar to that reported for polyethylene. Similar results were obtained from energy calculations that took into account both van der Waals and electrostatic interactions. Sectorized lamellar crystals were observed by decoration with polyethylene. Different folds involving methylene or ester groups exist at the lamellar surface depending of the growth sector.