Rubber structures:

Linear structure: general structure of the unvulcanized rubber. Because of large molecular weight, no external force, was fine dough. When the external force, external force is removed, the degree of entanglement fine group changes, the molecular chains rebound occurs, have a strong tendency to recovery, which is the origin of highly elastic rubber.

  Branched structure: branched chain macromolecular aggregates of rubber to form a gel. Gel rubber properties and processing are negative. When mixing various ingredients often can not enter the gel region, the formation of local blank, can not form a reinforcement and crosslinking, become weak parts of the product.

  Crosslinked structure: linear molecule with some of the bridging atom or group of atoms connected to each other to form a three-dimensional network structure. As the vulcanization course of conduct, this structure is continuously strengthened. Thus, the segment free activity decreased, and the elongation decreased plasticity, strength, elasticity and increased hardness, compression set and the degree of swelling decreased.