Aliphatic polyurethane prepolymers represent an important category within the polyurethane family, offering unique advantages in terms of durability, aesthetics, and resistance to environmental factors. Compared with aromatic systems, aliphatic polyurethanes exhibit superior color stability, excellent weather resistance, and long service life, which make them especially valuable in applications that require exposure to sunlight, heat, or moisture. Within this category, two major series can be identified: the LFH aliphatic prepolymers and the LW aliphatic prepolymers, each of which has its own performance advantages and areas of application.
The LFH aliphatic prepolymer series provides outstanding physical properties that are typical of aliphatic elastomers. These prepolymers are designed using HDI (hexamethylene diisocyanate) as a key monomer, combined with LF low-free technology that minimizes the level of residual HDI monomers. This low-free technology not only reduces harmful emissions and improves workplace safety, but also enables HDI-based systems to be applied in situations where they were previously unsuitable due to the high vapor pressure of conventional HDI. As a result, LFH prepolymers serve as an excellent foundation material for both cast elastomers and high-performance coating formulations.
The LW aliphatic prepolymer series is another innovation that focuses on processability and long-term performance. These prepolymers are characterized by their extended pot life, giving formulators and manufacturers more flexibility during the mixing, molding, or coating processes. In addition to excellent UV resistance, LW prepolymers also demonstrate remarkable hydrolysis resistance, even at elevated temperatures. This combination of features ensures that LW systems maintain their integrity and mechanical performance under harsh outdoor conditions, making them highly suitable for long-term use in demanding environments.
From an application perspective, aliphatic polyurethane prepolymers are widely recognized for their role in metal coatings and protective finishes. Their ability to resist yellowing, maintain gloss, and withstand outdoor weathering makes them an indispensable material for industries that demand both aesthetic appeal and functional durability. For example, they are often used in industrial equipment coatings, automotive and transportation finishes, and protective layers for architectural structures exposed to sunlight and rain. In addition, because of their superior hydrolytic stability, these prepolymers are also being explored in marine coatings and outdoor elastomer applications, where water resistance and long service life are critical.
