Selection of Polyurethane foam Catalyst

Polyurethane foam products are mainly synthesized by polyether, isocyanate, foaming agent, catalyst, etc. The main process of foam formation is generally considered as follows:

1. Foam is produced in the polyurethane reaction system by physical and chemical methods, and foam is evenly dispersed in the reaction system. The main foaming method is to use water and isocyanate to produce carbon dioxide to foam.

2. The production process of foam requires that the viscosity of the reaction system increases with the increase in order to stabilize the foam from escaping.

3. When the foam formation reaches the required number and size, the reaction system viscosity needs to continue to increase, or even form a cross-linking system to stabilize the foam and shape it into a product.

In this case, we need at least two catalysts to regulate the progress of the reaction. One catalyst is to promote the reaction between isocyanates and water, that is, to promote the foaming reaction. Usually, amine catalysts are chosen; Another type is to promote the reaction between isocyanates and polyethers or alcohols, that is, the reaction of polyurethane molecular chain growth and crosslinking, usually using metal catalysts. Therefore, in the process of polyurethane foam synthesis, we usually choose amine catalyst and organometallic catalyst to cooperate with each other, so as to produce synergy to achieve the best effect. The specific types and ratios of amine catalysts and organometallic catalysts need to be adjusted and selected based on different products through experiments or experience, and will not be elaborated here.