Contents Introduction 1.1. Overview of Polyurethane Materials 1.2. Role of Auxiliary Agents in Polyurethane Systems 1.3. Scope of this Article Classification of Polyurethane Auxiliary Agents 2.1. Catalysts 2.1.1. Amine Catalysts 2.1.2. Metal Catalysts 2.1.3. Blocked Catalysts 2.2. Surfactants 2.2.1. Silicone Surfactants 2.2.2. Non-Silicone Surfactants 2.3. Blowing Agents 2.3.1. Chemical Blowing Agents (CBAs) 2.3.2. Physical Blowing...