Low free TDI polyurethane prepolymers are an advanced class of materials that achieve breakthroughs in both performance and safety. Traditional TDI prepolymers exhibit good toughness, abrasion resistance, and processability, but they usually contain a relatively high level of residual free TDI monomer. During production and processing, this residual monomer releases harmful vapors, posing significant risks to workers' health and the workshop environment. Low-free TDI systems were developed as an upgraded solution to this problem. Through advanced separation and control technologies, the free TDI content is significantly reduced, creating a safer working environment while retaining the excellent overall performance of TDI systems.
Compared with conventional systems, low-free TDI prepolymers offer clear advantages in use. First, the substantially reduced monomer content minimizes the risk of workers inhaling harmful vapors, thereby improving overall workplace safety. Second, this system demonstrates lower viscosity and longer pot life, enabling operators to complete molding or casting processes more easily, enhancing processing efficiency, and reducing scrap rates. In addition, the lower exotherm during reaction leads to more uniform curing in the mold, resulting in faster demolding and better dimensional stability. These features not only increase production efficiency but also reduce downstream processing difficulties and costs.
In terms of performance, low-free TDI polyurethane prepolymers continue to deliver the outstanding abrasion resistance, toughness, and dynamic properties typical of TDI systems, withstanding high-impact and demanding service conditions. Their material structure provides excellent tear resistance and fatigue resistance, making them suitable for long-term use under heavy loads. At the same time, they maintain good flowability and adaptability during processing, allowing flexible adjustment of hardness and performance through formulation, thus meeting the diverse needs of different industries.
Currently, low-free TDI polyurethane prepolymers are mainly available in two series: polyether-based and polyester-based. Polyether-based products are known for superior hydrolysis resistance and low-temperature performance, often used in applications requiring long service life and resistance to environmental factors, such as seals and conveyor liners. Polyester-based products provide better wear resistance and mechanical strength, making them ideal for high-friction environments such as mining machinery parts, construction equipment components, and paper industry rollers. Together, these two product families offer users a broad selection of solutions.
The application scope of low-free TDI polyurethane prepolymers is wide-ranging. They are widely used in hose and belt manufacturing, providing abrasion resistance, pressure resistance, and fatigue resistance for industrial conveying systems. In material handling and transportation, they can be made into high-strength rollers and wear-resistant liners, ensuring long-term reliable operation of equipment. In the oil and gas industry, their resistance to oil and wear makes them ideal for seals, oil seals, and other critical components. In mining and construction machinery, low-free systems can significantly extend the service life of wear parts, reducing equipment maintenance costs. Additionally, in the paper industry, rollers made from low-free TDI provide excellent wear resistance and stability, ensuring long-lasting performance in high-speed paper machines.