Microphase Separation in Strain-Crystallizing Rubber

Based on a microscopic numerical model, we describe strain-induced crystallization in rubbers as a cooperative phenomenon governed by the formation of crystal superstructures. The main paradigm is that crystallization is faster than the relaxation of the matrix and can be modeled as a local process. During mechanical cycling, a microphase separation is observed, which is driven by more efficient strain regulation of parallely arranged crystals and even emerges without local interaction between crystals. By introducing direct crystal-crystal interaction, we are able to reproduce critical experiments performed on natural rubber. Our study suggests that strain crystallization, specifically its reinforcing and crack propagation inhibiting effects, cannot be fully understood on the level of a single crystal alone.

Automated summary

The study suggests that strain-induced crystallization in rubber is a cooperative phenomenon governed by the formation of crystal superstructures, with crystallization occurring faster than matrix relaxation and can be modeled as a local process. Microphase separation is observed during mechanical cycling, driven by more efficient strain regulation of parallel crystals, and introducing direct crystal-crystal interaction can reproduce critical experiments.