What are foaming promoters and foaming catalysts?

What are foaming promoters and foaming catalysts?

What are foaming promoters and foaming catalysts?
In the modification of plastics, foaming agents must be added when it is necessary to produce plastics with microporous structure. In order to expand the application scope of foaming agents in production, foaming promoters must be added, and foaming catalysts must be added to accelerate the foaming reaction rate. This article introduces the difference between foaming promoter and foaming catalyst.
Foaming accelerator is a kind of compound that can reduce the decomposition temperature of foaming agent. In the foaming system, it is generally required that the decomposition temperature of the foaming agent should match the melting temperature of the resin. This undoubtedly limits the scope of use of foaming agents. In order to expand the application scope of foaming agent during production, generally for solid resin, if the decomposition temperature of foaming agent does not match the melting temperature of resin, foaming accelerator can be added to reduce the decomposition temperature of foaming agent.
Foaming catalyst is a kind of compound that can accelerate the reaction rate, effectively control the foaming process, and establish a good balance between the molecular chain growth reaction and foaming. It is usually used in polyurethane (PU) and phenolic resin (PF) foaming systems.
There are many types of foaming promoters and foaming catalysts, and the common types of foaming promoters are mainly as follows:

① Zinc compounds, such as zinc oxide, zinc octanoate, zinc nitrate and fatty acid zinc soap.
② Lead compounds, such as lead carbonate, lead phthalate, lead phosphite, tribasic lead sulfate, dibasic lead phosphite, lead phosphite, lead stearate and lead oxide.
③ Cadmium compounds, such as cadmium caproate, cadmium caproate, cadmium laurate, cadmium soap of fatty acid, etc.
④ Organic acids, such as stearic acid, lauric acid, salicylic acid, etc. ⑤ Urea and its derivatives, such as urea, ammonia, ethanolamine, etc.
Foaming catalysts are mainly amine, tin compounds and acids, and the commonly used varieties are mainly as follows:
① Amines, mainly fatty amines and alcohol amines, such as triethylenediamine, dimethylhexadecylamine, trimethylaniline, triethylenediamine, triethanolamine, ethanolamine, etc., are mainly used in PU foaming system.
② Tin, mainly including stannous octanoate and dibutyltin dilaurate, is mainly used in PU foaming system.
③ Acids, mainly including hydrochloric acid, sulfuric acid, phosphoric acid, benzenesulfonic acid, petroleum sulfonic acid, etc., are mainly used in PF foaming system.