Polyurethanes (PUs) are a diverse family of plastics that we can find in wide variety of objects that surround us in everyday use. For example, foams in sleeping mattresses and shape memory pillows are PU foams, and so are the foams that are used for insulation of window frames and doors during construction. Thermoplastic PUs (TPUs) are extensively used in the production of shoe soles due to their durability, flexibility, and resistance to wear and tear. In the automotive industry, TPUs are used while making interior and exterior parts such as dashboards, door panels, and protective coverings. Their impact resistance and aesthetic qualities make them suitable for these applications. PUs also have many other useful applications in textiles, industrial insulation, medical devices, electronics etc.
The main issue with PUs is that they are produced from isocyanates – chemical compounds which are highly toxic and cancerogenic. They present significant respiratory and dermal hazards and can cause chronic illness or even death upon overexposure. Scientists are trying to substitute isocyanates with other compounds in order to reduce occupational hazards for workers who are frequently exposed to isocyanates.
One of the potential solutions is to use cyclic carbonates and diamines to produce polyhydroxyurethanes (PHUs) that are similar in structure to PUs and are usually considered as their greener alternative. However, current state of the art PHUs possess insufficient molecular weights and are very hydrophilic. These two factors combined result in poor mechanical properties and thus limit the practical utility of PHUs.
The SPRUT project was aimed at improving methods for PHU synthesis and developing method for their modification in order to reduce their hydrophilicity. The combined success of these two main goals will bring PHUs closer to industrial requirements and may allow to facilitate the substitution of toxic isocyanates at workplaces and everyday lives.