ABSTRACT
Chain extenders (or curatives) are low-molecular-weight reactants that produce the familiar elastomeric properties of the polyurethanes. Chain extenders typically have molecular weights in the range of 40-300 Da and can be classiŽed as either hydroxylterminated or amine-terminated. Difunctional compounds are considered chain extenders, while compounds with higher functionality are considered cross-linkers. A wide variety of different cross-linkers with different reactivities and functionalities are employed, for example, glycerol, trimethanol propane, glycols, and diamine compounds.
