table of contents introduction 1.1. polyurethane chemistry: a brief overview 1.2. the role of catalysts in polyurethane synthesis 1.3. scope of this review classification of polyurethane catalysts 2.1. amine catalysts 2.1.1. tertiary amine catalysts 2.1.2. cyclic amine catalysts 2.1.3. blocked amine catalysts 2.2. organometallic catalysts 2.2.1. tin catalysts 2.2.2. bismuth catalysts 2.2.3. zinc catalysts 2.2.4....