contents introduction 1.1. background of polyurethane rigid foam 1.2. role of catalysts in polyurethane foam formation 1.3. introducing pc-8 chemical nature and properties of pc-8 2.1. chemical structure and composition 2.2. physical and chemical properties 2.3. reaction mechanism pc-8’s influence on cream time 3.1. cream time defined 3.2. mechanism of cream time reduction by pc-8...