What is the main function of a vulcanizing agent?

1. Construction of a Three-Dimensional Network Structure (Cross-linking)

Core Mechanism: Under heating or catalytic action, the vulcanizing agent reacts with double bonds, sulfur atoms, or other active sites in the polymer chains to form chemical bonds (such as sulfur-sulfur bonds and carbon-sulfur bonds), connecting independent polymer chains into a three-dimensional network structure.

Effects:
* Increased Strength: The tensile strength and tear strength of the cross-linked material are significantly improved.
* Improved Elasticity: The network structure imparts high elasticity to the material, such as the ability of rubber to quickly return to its original shape after being subjected to stress.
* Enhanced Abrasion Resistance: Cross-linking reduces molecular chain slippage, lowering the wear rate.

2. Optimization of Physical Properties
* Hardness and Stress at a Fixed Elongation: By adjusting the amount of vulcanizing agent and vulcanization conditions, the hardness of the material can be precisely controlled (e.g., the difference between soft and hard rubber).

Heat Resistance: The cross-linked structure restricts the thermal motion of molecular chains, improving the stability of the material at high temperatures.

Resistance to Compression Set: Reduces residual deformation after long-term compression.

3. Improved Chemical Stability

Solvent Resistance: The cross-linked network hinders solvent molecule penetration, reducing the risk of material swelling or dissolution.

Aging Resistance: Reduces the damage to molecular chains caused by environmental factors such as ultraviolet radiation and ozone, extending service life.

Chemical Corrosion Resistance: Enhances the material's resistance to chemicals such as acids, alkalis, and oils.

4. Expanded Application Range

Functionalized Customization: By adjusting the vulcanization system, materials with special properties can be developed, such as:

Conductive Rubber: Adding conductive fillers and optimizing the vulcanization process.

Flame-Retardant Rubber: Combining flame retardants and vulcanizing agents to improve fire resistance.

Medical-Grade Silicone: Using biocompatible vulcanizing agents to ensure safety.

5. Environmental and Safety Impacts

Environmentally Friendly Vulcanizing Agents: With increasingly stringent regulations, low-toxicity and pollution-free vulcanizing agents (such as peroxides and resins) are gradually replacing traditional sulfur, reducing harmful gas emissions during processing. Kanglibang Adhesives has been continuously making breakthroughs in environmentally friendly applications.

Recycling: While the cross-linked structure improves performance, it may also affect the material's recyclability; a balance must be struck between performance and environmental requirements. Development Trends
* High-efficiency vulcanizing agents: Develop vulcanization systems with higher activity and lower dosage to reduce production costs.
* Composite vulcanization technology: Combine multiple vulcanizing agents and accelerators to achieve synergistic performance optimization.
* Green chemistry: Promote sulfur-free, low-volatile organic compound (VOC) vulcanization processes to meet sustainable development requirements.