Rubber or some polyolefin materials can obtain the required mechanical, thermal, or chemical properties through cross-linking reactions. According to different polymers and applications, this reaction can also be referred to as curing (especially thermosetting materials) or vulcanization (especially rubber and sulfur-containing materials).
Among these different crosslinking reactions, free radical chemical reactions are common. Generally speaking, one step always becomes a free radical. Organic peroxides as a source of free radicals. They generate highly active peroxy radicals through thermal decomposition, which can capture hydrogen atoms on the polymer backbone, especially CH2 units containing aliphatic groups. Then these macromolecular free radicals undergo branching and cross-linking reactions for recombination. Organic peroxides can be used alone or combined with multifunctional radical monomer.