TRANSFORMATIONS IN INTERMOLECULAR INTERAC TIONS OCCURRING IN THE COURSE OF DEFORMATION OF ELASTOMERS (ON THE EXAMPLE OF NONYLACRYLATE COPOLYMERS)

Model elastomers (nonylacrylate copolymers) with either varied density of physical cross-links and similar chemical nature of backbone chain s and molecular mass characteristics or, alternatively, with fixed den sity of cross-links and varied M(n) were synthesized. The behavior of the model polymers was studied in the course of uniaxial tension with constant strain rate (within 20 - 340 mm/min) or under strain interrup ted in the course of stretching to record the stress relaxation. Proce ssing of the data obtained allowed us to discriminate between the proc esses with different relaxation times and to consider the elastic and viscous contributions to stress. A model of physical network is propos ed, which considers the network as a sum of two components, a physical gel and sol. Mutual transformations of both components of physical ne twork in the course of deformation are considered and mechanism of the transformation is proposed.