What is the difference between polyurethane TDI, MDI and NDI?
TDI (Toluene Diisocyanate) is a commonly used polyurethane raw material, primarily applied in soft foams, elastomers, coatings, and other fields. Its chemical structure provides high reactivity, enabling it to react with polyols to form polyurethanes. However, TDI has some drawbacks during production and usage, such as yellowing, the release of toxic gases, and decomposition at high temperatures.
Polyurethane made with TDI has good elasticity and flexibility, making it suitable for soft foams and elastomer products. Due to its high reactivity, TDI is less ideal for producing high-strength and high-hardness polyurethane products.
TDI has a relatively low raw material cost, making polyurethane products made with TDI more cost-effective.
MDI (Methylene Diphenyl Diisocyanate) has higher reactivity and better heat resistance compared to TDI. Polyurethane made with MDI exhibits higher strength, hardness, and wear resistance, making it suitable for rigid foams, elastomers, adhesives, and other products. However, MDI also has drawbacks such as crystallization and the release of toxic gases.
Polyurethane made with MDI features superior strength, hardness, and wear resistance, making it ideal for rigid foams and elastomers. Compared to TDI, MDI offers better heat resistance and higher reactivity.
MDI is more expensive than TDI, resulting in higher production costs for polyurethane products made with MDI.
NDI (Naphthalene Diisocyanate) is a new polyurethane raw material with high reactivity and excellent heat resistance. Polyurethane made with NDI boasts outstanding strength, hardness, and wear resistance, making it suitable for high-performance applications such as engineering plastics and specialty elastomers. However, NDI has drawbacks such as high production costs and crystallization tendencies.
NDI-based polyurethane provides exceptional strength, hardness, and wear resistance, making it suitable for high-performance products like engineering plastics and specialty elastomers. Compared to TDI and MDI, NDI offers superior heat resistance and better dimensional stability.
NDI is more expensive than both TDI and MDI. However, with advancements in production technology and the gradual industrialization of NDI manufacturing, its cost is expected to decrease over time.