Abstrato

Studying on the mechanism and raw materials used to manufacturing polyurethane

A.Shokuhi Rad, M.Ardjmand

Polyurethanes (PU) are present in various aspects of advanced life. They represent is a class of polymers that have found a propagate use in the medical, automotive and industrial fields. Polyurethanes are produced by the polyaddition reaction of a polyisocyanate with a polyalcohol (polyol) in the presence of a catalyst and other additives. In this case, a polyisocyanate is a molecule with two or more isocyanate functional groups, R-(N=C=O)n2 and a polyol is a molecule with two or more hydroxyl functional groups, R’-(OH)n2. The reaction product is a polymer containing the urethane linkage, -RNHCOOR’. Though the properties of the polyurethane are determined mainly by the choice of polyol, the diisocyanate exerts some influence, and must be suited to the application. The cure rate is influenced by the functional group reactivity and the number of functional isocyanate groups. The mechanical properties are influenced by the functionality and the molecular shape. Diazobicyclo [2.2.2]octane (DABCO) was used to comprehension of PU preparation mechanism when two monomers are stiring the together.