Polyurethane Foams

Polyurethane foams (PUFs), divided into flexible and rigid types, are one of the most widely used polyurethane products in the furniture, automobile, insulation, and construction industries. About 15 million tons of polyurethane are annually produced for various applications due to the diversity of their raw materials. Polyurethanes (PU) are conventionally derived from two main parts, polyols and isocyanates. The PUF formulation significantly affects the final foam’s structure, properties, and morphology. Several organic and inorganic nanostructures, such as graphite, graphene, graphene oxide, carbon black, carbon nanotube, and nano clays, have been used to fabricate composite foams to enhance their performance. Applications of polyurethane composite foams are mainly focused on aerospace and automotive industries, radar absorption and electromagnetic interference shielding, oil absorbent, sensors, fireproofing, shape memory, and biomedical materials. In this chapter, after a description on the raw materials, fabrication methods, properties of PUFs, their different applications have been elaborated in detail, Moreover, isocyanate-free synthesis of polyurethane foams and also their recycling methods will be discussed as two main environmental protection strategies.