free volume

Five series of polyheteroarylenes have been investigated with regard to their physical properties before and after swelling with a supercritical carbon dioxide. The study of the dependence of the glass transition temperature and the free volume of polymers on their conformational rigidity showed that the process of swelling in the supercritical carbon dioxide is influenced by the voluminous side groups and by the high boiling solvent N-methylpyrrolidinone used for preparation of the polymers which facilitates the formation of crosslinks or complexes with the macromolecular chains.

The property of brittleness for polymers and polymer-based materials (PBMs) is an important factor in determining the potential uses of a material. Brittleness of polymers may also impact the ease and modes of polymer processing, thereby affecting economy of production. Brittleness of PBMs can be correlated with certain other properties and features of polymers; to name a few, connections to free volume, impact strength, and scratch recovery have been explored. A common thread among all such properties is their relationship to chemical composition and morphology.