What are polyurethane TDI, MDI, and NDI?
TDI, MDI, and NDI are three important polyurethane materials, which have obvious differences in chemical structure, performance, and use. The following is a brief introduction to these three materials and a comparison of their advantages and disadvantages, performance differences, and cost analysis.
TDI (toluene diisocyanate) is a commonly used polyurethane raw material, mainly used in soft foams, elastomers, coatings, 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 during production and use, such as yellowing, release of toxic gases, and easy decomposition at high temperatures.
Polyurethane made from TDI has good elasticity and softness, and is suitable for making soft foams, elastomers, and other products. Due to its high reactivity, TDI is slightly insufficient for making high-strength and high-hardness polyurethane products.
The price of TDI raw materials is relatively low, so the cost of using TDI to make polyurethane is relatively low.
MDI (diphenylmethane diisocyanate) has higher reactivity and better heat resistance than TDI. Polyurethane made from MDI has high strength, hardness and wear resistance, and is suitable for making rigid foams, elastomers, adhesives and other products. However, MDI also has some disadvantages in the production and use process, such as easy crystallization and release of toxic gases.
Polyurethane made from MDI has high strength, hardness and wear resistance, and is suitable for making rigid foams, elastomers and other products. Compared with TDI, polyurethane made from MDI has better heat resistance and higher reactivity.
The price of MDI raw materials is relatively high, so the cost of using MDI to make polyurethane is relatively high.
NDI (naphthalene diisocyanate) is a new type of polyurethane raw material with high reactivity and excellent heat resistance. Polyurethane made from NDI has excellent strength, hardness and wear resistance, and is suitable for making high-performance polyurethane products such as engineering plastics, special elastomers, etc. However, NDI also has some disadvantages in the production and use process, such as high production cost and easy crystallization.
Polyurethane made from NDI has excellent strength, hardness and wear resistance, and is suitable for making high-performance polyurethane products such as engineering plastics, special elastomers, etc. Compared with TDI and MDI, polyurethane made from NDI has higher heat resistance and better dimensional stability.
The price of NDI raw materials is relatively high, so the cost of using NDI to make polyurethane is also relatively high. However, with the continuous advancement of production technology and the gradual realization of industrialized production, the cost of NDI is expected to gradually decrease.