A polyurethane catalyst is a substance that increases the rate of the reaction between isocyanate and hydroxyl groups. This reaction is responsible for the formation of polyurethane polymers. The type of catalyst used will depend on the desired properties of the final polyurethane product.

There are many different types of catalysts used in polyurethane production. Some of the most common types include:

Amines: Amines are the most commonly used catalysts in polyurethane production. They efficiently catalyze the reaction between isocyanates and hydroxyl groups. However, amines also lead to the formation of undesired by-products, such as amines and amides.
Organotin compounds: Organotin compounds are also effective in catalyzing the reaction between isocyanates and hydroxyl groups. However, they are more expensive and difficult to handle than amines.
Metal salts: Metal salts, such as zinc chloride, can also be used as polyurethane catalysts. They are less expensive than amines and organotin compounds, but they are not as effective at catalyzing the reaction between isocyanates and hydroxyl groups.
The choice of catalyst depends on many factors, including the type of polyurethane resin used, the desired properties of the final product, and the cost of the catalyst.

Catalysts are an important part of the polyurethane manufacturing process. They help ensure that polyurethane resins are cured properly and that the final product has the desired properties.

Here are some properties that can be controlled by choosing a catalyst:

Cure Rate: The cure rate is the rate at which the polyurethane resin hardens. Catalyst selection can be used to control the rate of cure so that the final product can be produced in the desired time.
Hardness of the final product: The hardness of the final product depends on the type of catalyst used. Amine catalysts tend to give softer products, while organotin compounds tend to give harder products.
Flexibility of the final product: The flexibility of the final product also depends on the type of catalyst used. Amine catalysts tend to give more flexible products, while organotin compounds tend to give less flexible products.
Toughness of the final product: The toughness of the final product depends on the type of catalyst used. Amine catalysts tend to give tougher products, while organotin compounds tend to give less tough products.
Catalyst selection is an important link in the polyurethane manufacturing process. Suitable catalysts can be used to produce polyurethane products with desired properties.