Zero-length crosslinkers are special chemicals that can form crosslinks between two or more polymer chains without the use of any external additives, thereby improving the physical and chemical properties of the polymer. The chemical structure of zero-length crosslinkers usually consists of two parts: one part is a highly reactive functional group, such as a bifunctional group or a dead group, and the other part is an inactive group, such as an alkyl group, an aryl group, etc. These inactive groups can form stable chemical bonds between polymer chains, thereby achieving the purpose of crosslinking.