The Limitations and Improvements of Polyurethane Adhesives

1.Toxicity issues and improvements

The presence of free isocyanate monomers in polyurethane adhesives poses significant toxicity problems. To address this issue, a new type of epoxy-based polyurethane can be obtained by combining end-hydroxyl polyfunctional epoxides with end-isocyanate-based polyurethane prepolymers. This compound is then mixed with polyamine compounds to create a new type of Polyurethane Adhesive. This adhesive combines the advantages of both epoxy resins and polyurethanes, and significantly reduces the content of free isocyanate monomers. 

2. Curing speed and high-temperature resistance

The curing speed of polyurethane adhesives at room temperature is relatively slow, and sometimes it may take several days for complete curing. To improve this performance, a multi-component compounding method can be adopted, which can significantly shorten the curing time at room temperature and enhance the convenience of use. At the same time, to enhance its high-temperature resistance, nanoparticles can be introduced into the polyurethane adhesive to effectively improve its key properties such as tensile strength, shear strength, and peel strength. 

3. Modification Technology

A method of enhancing the comprehensive performance of polyurethane adhesives by adding nanoparticles is currently under research. This modification technology not only improves their mechanical properties but also opens up new development directions for polyurethane adhesives.