The Difference Between Polyurethane Catalysts TDI And MDI

The Difference Between Polyurethane Catalysts TDI And MDI

TDI and MDI are both important polyurethane catalyst materials, and they have obvious differences in chemical structure, performance and use.

TDI (toluene diisocyanate) is a commonly used polyurethane raw material, mainly used in soft foam, elastomer, coating and other fields. The chemical structure of TDI makes it highly reactive and can react with polyols to form polyurethane. However, TDI has some disadvantages in the production and use process, such as yellowing, release of toxic gases, and easy decomposition at high temperatures.

Performance difference: Polyurethane made from TDI has good elasticity and softness, and is suitable for making soft foam, elastomer and other products. Due to its high reactivity, TDI is slightly insufficient for making high-strength and high-hardness polyurethane products.

Cost: The price of TDI raw materials is relatively low, and the cost of making polyurethane using TDI is relatively low.

Compared with TDI, MDI (diphenylmethane diisocyanate) has higher reactivity and better heat resistance. Polyurethane made from MDI has higher strength, hardness and wear resistance, and is suitable for making hard foam, elastomer, adhesive and other products. However, MDI also has some disadvantages in the production and use process, such as easy crystallization and release of toxic gases.

Performance difference: Polyurethane made from MDI has higher strength, hardness and wear resistance, and is suitable for making rigid foam, elastomer and other products. Compared with TDI, polyurethane made from MDI has better heat resistance and higher reactivity.

Cost: The price of MDI raw materials is relatively high, so the cost of using MDI to make polyurethane is relatively high.

In summary, TDI, MDI and have obvious differences in chemical structure, performance and use. Among them, TDI has better elasticity and softness, and is suitable for making soft foam, elastomer and other products; MDI has higher strength, hardness and wear resistance, and is suitable for making rigid foam, elastomer and other products, and should be considered comprehensively according to the performance requirements and cost factors of the product.