Chain structure, phase morphology, and toughness relationships in polymers and blends

We present chain structure, phase morphology, and toughness relationships in thermoplastic polymers and polymer/rubber blends. In neat polymers, molecular aspects of craze/yield behavior are controlled by two chain parameters: entanglement density ν e and characteristic ratio C ∞ . The crazing stress is proportional to ν , and the yield stress is proportional to C ∞ . The dispersed rubber toughens a polymer/rubber blend mainly by promoting energy dissipation of the matrix. The toughening efficiency correlates with the rubber phase morphology and the chain structure of the matrix.