Deformation-Induced Morphology Evolution of Protein-Lipid Aggregates and Its Relationship with Mechanical Properties of Vulcanized Natural Rubber

The nonrubber components in natural rubber (NR), mainly proteins and lipids, are crucial for the outstanding comprehensive properties of NR through the formation of a naturally occurring network. However, how the morphology of nonrubber components changes during deformation and the effect of such changes on the mechanical properties of vulcanized NR remain unclear. Here, by using confocal laser scanning microscopy to track the morphology evolution of nonrubber components during deformation, the results reveal that the aggregates of proteins and lipids gradually disintegrate into smaller particles with increasing strain. This phenomenon represents the preferential collapse of a naturally occurring network under an externally applied load. Such a sacrificial characteristic of a naturally occurring network leads to energy dissipation, thereby enhancing the mechanical properties of vulcanized NR. The findings provide mechanistic insights into the structure-property relationship of NR, which can inspire the design of high-performance synthetic elastomers.