A brief discussion on polyurethane catalysts

A-1 is a solution composed of 70% bis(dimethylaminoethyl) ether and 30% dipropylene glycol , mainly used for soft polyether polyurethaneFoam plasticProduction of foaming tertiary amine Catalyst, also known as front-stage catalyst. A-1 has a particularly strong catalytic effect on water, so it can reduce the foam density. It has catalytic activity for both polyurethane foaming and gelling reactions, and is especially effective for foaming reactions. It has high flexibility in regulating and controlling foaming reactions. It is used to control about 80% of the reactions that generate gas. It is used for The efficacy of controlling the gel reaction accounts for about 20%. The strong catalytic effect on the foaming reaction can be balanced by A-33 strong gel.

A-1 mainly plays a role in promoting gas generation and generating CO during the foaming process2. When the amount of A-1 is small, there is insufficient gas generation, and it is difficult for the gas to escape, resulting in closed cells of the product; as the amount of A-1 increases, the foaming reaction accelerates, the porosity of the product increases, the density of bubbles in the system increases, and the cells The pore size decreases; when the amount of A-1 is too large, because the foaming reaction is faster than the gel reaction, large bubbles and defects begin to appear in the system, the pore size increases, and even collapse occurs. WhenA-1 is within a certain range, the tensile strength of the foam increases with the amount of A-1 The increase first increases and then decreases, and the tear strength of the foam also increases first and then decreases. Therefore, when we prepare the formula, it is particularly important to adjust the amount of catalyst.