What are the common types of polyurethane curing agents?

Polyurethane curing agent is an important component of polyurethane materials. Its function is to react with isocyanate in polyurethane prepolymers to form high-molecular polymers with characteristics such as strength, hardness and heat resistance. The common types of polyurethane curing agents include the following:

 

1. Polyol curing agents: such as propylene glycol, ethylene glycol, polyether diol, etc. This type of curing agent undergoes etherification with isocyanate during the reaction to form polyurethane materials.

 

2. Polyamide curing agents: such as diisocyanate carbamate, diisocyanate urea, etc. This type of curing agent undergoes interpenetrating polymerization with isocyanate during the reaction, forming polyurethane materials.

 

3. Oxide-based curing agents: such as potassium hydroxide, sodium hydroxide, lead oxide, etc. This type of curing agent undergoes an acid-base neutralization reaction with isocyanate during the reaction, forming polyurethane materials.

 

4. Acid-based curing agents: such as phthalic acid, stearic acid, etc. This type of curing agent undergoes anhydride reaction with isocyanate during the reaction, forming polyurethane material.

 

5. Silicone-containing curing agents: such as isocyanate-based polyamides, polysilicates, etc. This type of curing agent undergoes a siloxane bond formation reaction with isocyanate during the reaction, forming polyurethane materials.

 

The main function of polyurethane curing agents is to enhance the bonding strength, weather resistance, chemical resistance, heat resistance of polyurethane materials, and reduce their brittleness. Youdaoplaceholder0 In addition, it can also enhance the strength of Polyurethane Adhesive, increase its crosslinking degree and cohesion energy, thereby enhancing the strength, weather resistance and other properties of the final product.

 

Polyurethane curing agent, through reaction with the main agent, forms a uniform soft and hard block copolymerization 3D cross-linked network structure, that is, a dense and uniform high-molecular film layer structure, thereby enhancing the structural stability, weather resistance, chemical resistance, heat resistance of polyurethane and reducing its brittleness. This structure ensures the slow-release property, elasticity, high and low temperature resistance and other properties and qualities of the polyurethane polymer film.