Simulations of crazing in polymer glasses: Effect of chain length and surface tension

Craze formation determines the effective strength of many structural polyme rs and glassy polymer adhesives. We use molecular dynamics simulations to s tudy the evolution of craze formation in glassy polymers as the number of m onomers per chain N increases. When N is less than the entanglement length N-e, the polymer cavitates and then fails along a simple fracture plane. As N becomes greater than N-e, the mode of failure changes, and the entire vo lume deforms into a craze. As in experiment, crazing occurs at a constant p lateau stress S and expands the volume of the polymer by a fixed extension ratio lambda.