IMPACT BEHAVIOR OF NYLON RUBBER BLENDS .6. INFLUENCE OF STRUCTURE ON VOIDING PROCESSES - TOUGHENING MECHANISM

Dilatometry tests were performed on nylon-rubber blends with various rubber concentrations, particle sizes and types of impact modifier. Whereas rubber concentration and particle size do not affect the onset of voiding in the blends during a tensile test, the type of elastomer used has a considerable effect. A correlation exists between the stress at which the rubber particles cavitate (or detach from the matrix) in the tensile test and the impact behaviour of the blend. A toughening mechanism is proposed in which the cavitation stress of the rubber and the interparticle spacing play crucial roles.