ABSTRACT
This chapter discusses breakthroughs in the development of transparent polyurethane plastics: bubble-free preparations, extensive range of formulations, and stabilization. When one thinks of polyurethanes, they might think of flexible foam, rigid foam, elastomers, coatings, or even thermoplastic urethane rubber, but they are unlikely to think of thermosetting rigid plastics. It is a niche area and within that niche is a subset of non-yellowing, water-white, transparent plastics. Polyurethanes containing aromatic groups such as benzene rings comprise the majority of polyurethane usage. Studies were conducted to optimize the adhesion of the polyurethane cladding to the polycarbonate. “Fusion Bonding” and “Cast In Situ” techniques were both optimized. The impact properties of SierracladTM composites or monolithic clad specimen were extensively tested. The results were very promising. The deep forming of domes showed that the formulations were too cross-linked.
