Simulation of Fracturing Reinforced Polymer Blends

Brownian dynamics simulations are used to simulate the fracture of a polymer/polymer interface that is reinforced by ``connector'' chains. The connectors can weave back and forth across this boundary, forming either single or multiple ``stitches.'' The work needed to fracture this interface is calculated as a function of the architecture and conformation of the connectors. The results show that the multistitch connectors dramatically improve the strength of the interface. This is rationalized through scaling arguments and explains recent experimental studies. The conclusions provide experimental guidelines for synthesizing effective connectors and thereby fabricating high-strength composites.