The Constants 2C1 and 2C2 in Phenomeno-Logical Elasticity Theory and Their Dependence on Experimental Variables

Abstract

There has been a very large number of experimental studies of the elastic properties of amorphous polymer networks in uniaxial deformation, particularly elongation, over the past few decades. In spite of these efforts, and related theoretical investigations, major questions remain unanswered with regard to stress-strain isotherms over the range of moderate deformations. The major question in this area is the molecular basis or interpretation of the phenomenological constants 2C1 and 2C2 used to represent the experimentally observed isotherms. It is hoped that the present survey of the results of the most important of these experimental studies, particularly in regard to the effect of experimental variables on 2C1 and 2C2 will encourage additional work, leading to an unambiguous solution to this important unsolved problem in the area of rubberlike elasticity.