MECHANICAL-PROPERTIES OF POLYVINYL-CHLORIDE) POLY(ACRYLONITRILE-CO-BUTADIENE) BLENDS WITH MODULATED STRUCTURE

Mechanical properties were investigated by the uniaxial tensile test combined with small angle light scattering. A 50:50 plastic-rubber blend has a high initial modulus which is close to that of the rigid plastic. Nevertheless, it can deform to a large extension ratio up to 6. It cannot immediately recover to its original length after the stress-strain test. However, after release from the instrument the film gradually shrinks to its original length at room temperature. After strain recovery the film shows a stress-strain curve almost identical to the original. The stretched film healed by resting at room temperature. A helical spring model interprets well the dependence of Young's modulus on the blend composition and the periodic distance of the modulated structure.