Retardation of amine catalyst A300: Strategies to reduce defects in polyurethane products Introduction Polyurethane (PU) is a multifunctional material widely used in the fields of construction, automobile, furniture, footwear, etc. However, various defects are often encountered in the production process of polyurethane products, such as bubbles, shrinkage holes, uneven surfaces, etc. These defects not only...