ABSTRACT
Polyurethane foams are referred as urethane foams. The abbreviation PUR is commonly used for polyurethane. PUR foams can be classified into two categories: flexible foams and rigid foams. The PUR skeleton consists of polyol and polyisocyanate. Polyols can be considered the building blocks, and polyisocyanates can be considered the jointing agent. Therefore, polyurethane foam chemistry is considered a building block chemistry. All kinds of polyurethane foam are prepared by the proper choice of polyol and polyisocyanate in respect to chemical structure, equivalent weight, and functionality.
