Cavitation‐Induced Stress Whitening in Semi‐Crystalline Polymers

Cavitation‐induced stress whitening in semi‐crystalline polymers during stretching significantly influences the physical properties of the materials. This review summarizes studies focusing on two different cavitation processes triggered at small and large strain regimes. The corresponding mechanisms of these two cavitation processes are discussed. For cavitation activated at small strain, there are two basic but distinctly different models with the initiation of cavities either in the amorphous phase or in the crystalline skeleton. For the cavitation triggered at a large strain regime, there are also two different arguments being either due to the defects located in the ends of micro‐fibrils or as a consequence of the fragmentation of load‐bearing inter‐fibril/micro‐fibril tie chains in highly oriented amorphous networks. A unified understanding of the cavitation processes during stretching semi‐crystalline polymers based on interpenetrated network model is proposed. Finally, this review outlooks future research topics for better understanding the cavitation mechanism to meet the industrial need. Stress whitening in polymers during stretching is considered to be a result of cavitation in the system. This review highlights two different cavitation processes triggered at distinct strain regimes. The cavitation around the yield point usually continues to large strains without causing catastrophic breakage of the material while the large strain cavitation ends up with polymer failure soon after activation.