Structural Composition of Rubber Products

The molecular structure of rubber products directly determines their processing behavior and final performance. Different structural types of rubber are suitable for various industrial applications, such as automotive components, specialty cables, and sealing parts.

1. Linear Structure

This is the typical structure of unvulcanized rubber. Due to its large molecular weight, the material appears as a fine, coiled mass under no external force. When stretched, the molecular chains extend and return to their original state once the force is removed — this reversible deformation is the fundamental reason for rubber’s high elasticity.

Rubbers with a linear molecular structure are commonly used in products requiring high flexibility and fatigue resistance, such as high-flexibility cable sheaths and automotive vibration-damping components.

2. Branched Structure

When rubber macromolecules develop a large number of side branches, they tend to aggregate and form gels. The presence of gel reduces processability and mechanical strength. During mixing and compounding, excessive branching causes poor dispersion of additives and fillers, creating weak zones that compromise reinforcement and crosslinking efficiency.

Therefore, in the production of special cable rubber sheath materials, it is essential to strictly control the gel content to ensure the stability of the insulation and outer protection layers.

3. Crosslinked Structure

When linear molecular chains are connected by sulfur atoms or other crosslinking bridges, a three-dimensional network structure forms. As the vulcanization process progresses, this structure becomes denser, reducing chain mobility, plasticity, and elongation, while significantly increasing strength, elasticity, and hardness. At the same time, compression set and swelling decrease.

This crosslinked molecular structure forms the foundation of high wear-resistant and heat-resistant specialty cable rubber sheaths, allowing them to maintain excellent mechanical and electrical insulation performance under high temperature, electrical stress, and mechanical load conditions.

The molecular structure of rubber products directly determines their processing behavior and final performance.