DEFORMATION-BEHAVIOR OF THERMOPLASTIC ELASTOMER BLENDS BASED ON POLY(PROPYLENE) AND ETHYLENEPROPYLENEDIENE RUBBER

Effects of the deformation rate and temperature on the mechanical prop erties (initial modulus of elasticity at a 1% relative elongation, ela stic moduli at a relative elongations of 100 and 300%, ultimate streng th, and elongation at break) of thermoplastic elastomer blends based o n poly(propylene) and cross-linked ethylenepropylenediene rubber were studied. The stress-strain sigma can be linearized in the sigma - (lam bda - lambda(-2)) coordinates (lambda = 1 + epsilon) and do not pass t hrough the origin. The elastic moduli exhibit a linear growth with inc reasing lg(epsilon) over dot and decrease with increasing temperature. The results are interpreted within the framework of the theory of vis coelasticity. The viscoelastic properties of the samples studied can b e described by the Williams-Landell-Ferry equation. A mechanism of the deformation development in the blend is proposed, according to which polypropylene is deformed in the first stage, and polypropylene togeth er with cross-linked elastomer, in the second stage. The strength and elongation at break are determined predominantly by the tension of cro ss-linked elastomer.