The main function of vulcanizing agents

Vulcanizing agents are indispensable key additives in the processing of polymer materials such as rubber and plastics. Their main function is to transform linear or branched polymers into three-dimensional network structures by initiating or promoting cross-linking reactions, thereby significantly improving the physical properties and chemical stability of the materials. The following are the main functions and specific mechanisms of vulcanizing agents:

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 damage to molecular chains caused by environmental factors such as UV radiation and ozone, extending service life.

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

4. Recommended Product: Silicone Platinum Curing Agent C-100AB

Product Model: C-100A and C-100B are platinum addition-type silicone crosslinking agents. Crosslinked silicone products can meet FDA requirements.

Product Characteristics: Non-toxic, odorless, highly transparent, and with excellent anti-yellowing properties. For products with strict requirements on low molecular weight content, a secondary curing process is recommended.

Applicable Materials: Suitable for food-grade products such as mobile phone buttons, nipples, and cake molds; also suitable for moldless hot air curing products such as medical silicone tubing and drinking tubing, with extremely high transparency.

5. Expanding Material Applications

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.

6. Environmental and Safety Impacts

Environmentally Friendly Vulcanizing Agents: With increasingly stringent regulations, low-toxicity, 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 cross-linking structures improve performance, they may also affect material recyclability; a balance must be struck between performance and environmental requirements.

Development Trends

High-Efficiency Vulcanizing Agents: Developing vulcanization systems with higher activity and lower dosage to reduce production costs.

Composite Vulcanization Technology: Combining multiple vulcanizing agents and accelerators to achieve synergistic performance optimization.

Green chemistry: Promoting sulfur-free, low-volatile organic compound (VOC) vulcanization processes aligns with sustainable development requirements.

Vulcanizing agents fundamentally alter the properties of polymer materials through cross-linking reactions, transforming them from easily deformable thermoplastics into practically valuable elastomers or thermosetting materials, widely used in automotive, electronics, medical, and construction industries.