The elasticity and related properties of rubbers

The relation of rubbers to other classes of polymers and the molecular basis of rubber elasticity are briefly examined. The methods used in the quantitative development of the statistical-thermodynamic theory of a molecular network are outlined, and the main conclusions, in the form of stress-strain relations, etc, are presented and compared with experimental data. Also examines the photoelastic properties of rubbers from both theoretical and experimental standpoints and discusses in detail the evidence derived from photoelastic studies on the statistical segment length in the molecular chain and its relation to intramolecular energy barriers. The thermodynamic analysis of stress-temperature data for rubber and other polymers, with particular reference to the internal energy and entropy changes during extension under constant pressure or constant volume conditions is studied. The phenomena of swelling in liquids is considered.