Vulcanization Vulcanization Vulcanization (British: vulcanisation) is a chemical process used to harden rubber. Vulcanization traditionally referred to the treatment of natural rubber with sulfur and this remains the most common example, however the term has also grown to include the hardening of other (synthetic) rubbers via various means. Examples include silicone rubber via room temperature vulcanizing and chloroprene rubber (neoprene) using metal oxides. Vulcanisation can therefore be defined as the curing of elastomers; with the terms 'vulcanization' and 'curing' sometimes used interchangeably in this context. It works by forming cross-links between sections of polymer chain which results in increased rigidity and
Rubber toughening and the energy to break rubber particles could account for the increased energy absorption of toughened polymers. This theory was limited, only accounting for a small fraction of the observed increase in fracture energy. The matrix crazing theory focuses on explaining the toughening effects of crazing. Crazes start at the equator where principal strain is highest, propagate perpendicular to the stress, and end when they meet another particle. Crazes with perpendicular fibrils can eventually become a crack if the fibrils break. The volume expansion associated with small crazes distributed through a large volume compared to the small volume of a