Multifunctional material: Polyurethane adhesive

Polyurethane adhesives refer to adhesives whose molecular chains contain amine carbamate groups or isocyanate groups. Since researchers first discovered their application in the bonding of metals and rubber in the 1940s, due to their outstanding comprehensive performance, they have become an important type among the eight major synthetic adhesives. 

 

Its core advantage stems from its unique chemical structure: the polar groups in the molecular chain can react with the active hydrogen on various substrate surfaces to form chemical bonds, while also exerting extremely strong chemical adsorption and hydrogen bonding forces on materials such as metals, glass, plastics, wood, leather, and textiles. Moreover, the main chain of polyurethane adhesives has good flexibility, enabling them to possess excellent impact resistance, fatigue resistance, and outstanding low-temperature performance, and being able to bond with substrates of different thermal expansion coefficients. By adjusting the formula, the adhesive layer can vary from flexible to rigid to meet different application requirements. 

 

In the application field, polyurethane adhesives are almost everywhere. In automotive manufacturing, they are widely used for bonding windshields, composite materials and interior components, helping to reduce the weight of the vehicle body. In the construction, footwear, packaging and furniture industries, they are also indispensable connecting materials. In recent years, with the rise of the new energy industry, polyurethane adhesives have successfully been applied to the structural bonding and fixation of photovoltaic energy storage cells, demonstrating their durability under complex conditions. 

 

Currently, the global Polyurethane Adhesive market is expanding steadily. The market size is expected to reach approximately 10.49 billion US dollars by 2025 and will exceed 18.96 billion US dollars by 2035. The industry development presents two significant trends: one is environmental friendliness, as environmental regulations become increasingly strict, low-volatile organic compound products such as solvent-free, water-based, and hot-melt types are accelerating the replacement of traditional solvent-based adhesives; the other is high-performance and multi-functionality, by introducing bio-based raw materials, nanomaterials, or special structural designs, new products with high bonding strength, flame retardancy, degradability, and recyclability are developed to meet the demands of cutting-edge fields such as electronics and aerospace.