Polyurethane is a versatile thermoplastic polymer with a range of characteristics (tensile strength, chemical resistance, thermal stability, and processability) as coating, elastomer, foam, and fiber for technical application. Epoxy resin, on the other hand, is thermoset having fine mechanical, chemical, and adhesion properties to be utilized as adhesives, coatings, and matrix for advanced composite materials. However, epoxy resins are rigid and brittle in nature and have poor crack resistance. To overcome these problems, polyurethane phase has been introduced in the epoxy network for toughening. Considerable research has been carried out to introduce a second reactive polymer in the matrix to generate interpenetrating polymer network (IPN). Consequently, mechanical properties, glass transition behavior, thermal resistance, and damping features of polyurethane have been enhanced by introducing epoxy to form polyurethane/epoxy interpenetrating polymer network structure. Different modifiers have been employed to modify the properties of polyurethane/epoxy IPNs such as montmorillonite nanoclay, fibers, fly ash, conducting polymers, etc. The polyurethane/epoxy crosslinked networks have shown a range of high‐performance application in ion‐exchange resins, aircraft, engineering materials, biomedical devices, and other commercial IPN products.
Part of the book: Aspects of Polyurethanes