Glasses and Amorphous Material

Abstract

Steric constraints can inhibit the packing of polymer chains and not allow an ordered structure to be created. The physical properties of the disordered state resembles those of a glass and the characteristic glass transition in which the polymer changes from a glass to a rubbery state is observed. The glass transition is associated with the concept of free volume and this chapter considers how it can be measured and its effects on the physical properties of the polymer. The glass transition is connected with molecular motion of the chain backbone and is influenced by the structure of the polymer backbone and its molecular weight. The effects of pressure and ageing can influence the glass transition and these effects are briefly considered. The concepts of fragility theory attempt to rationalize the properties of the glass state in all materials and are outlined.