THE EFFECT OF LOW-MOLECULAR-MASS LIQUIDS ON PHYSICAL NETWORK AND VISCOELASTIC PROPERTIES OF CROSS-LINKED AMORPHOUS POLYDIENEURETHANES

Deformational behavior of cross-linked amorphous polydieneurethanes in the presence of nonpolar and proton-accepting low-molecular-mass liqu ids was studied. As evidenced by IR spectroscopy, the breakdown of the network of interchain physical bonds in polyurethanes was realized no t only in the presence of proton-accepting but also in the presence of nonpolar compounds, which functioned as diluents. Within the framewor k of the theory of elasticity, the effect of plasticizing agents on po lymer deformation and a concomitant transformation of the properties o f three-dimensional network from the properties associated with an aff ine network to the properties corresponding to a phantom network were considered. For the elastomers studied, a model providing an adequate description for the dependences between tensile stress and strain in a wide range of variations of strain rates and concentrations of plasti cizing agents in elastomers was advanced.