Linear structure: Common structure of unvulcanized rubber. Due to the large molecular weight, without external force, macromolecular chains appear random coil curve group. When external forces act and withdraw forces, the entanglement degree of the wire group changes, the molecular chain rebounds and has a strong tendency to recover, which is the origin of the high elasticity of rubber.
Branched structure: Aggregation of branched chains of rubber macromolecular chains to form gels. Gel is bad for rubber properties and processing. In the process of mixing, various compounds often can not enter the gel area, form local blank, the formation of reinforcement and crosslinking, become the weak part of the product.
Crosslinked structure: Linear molecules are connected to each other by the bridging of atoms or groups of atoms, forming a three-dimensional network structure. The structure is strengthened as the curing process progresses. In this way, the free movement of the chain segment decreases, the plasticity and elongation decrease, the strength, elasticity and hardness increase, the compression permanent deformation and swelling degree decrease.
The influence of rubber structure
The influence of rubber reinforcing properties is mainly focused on the tensile strength and tearing strength. The general rule is as follows: when the particle size is the same, the reinforcement effect of high structure carbon black on non-crystalline rubber is great, and generally has higher tensile strength and tearing strength. The rubber structure is also the most important factor affecting the conductive property. The chain-dendritic structure is easy to form an interwoven conductive path in the rubber, which will improve the conductive property. The molecular chain of rubber can be crosslinked. When the rubber is deformed by external force after crosslinked, it has the ability to recover quickly and has good physical and mechanical properties and chemical stability.
