Introduction Of Polyurethane Catalyst

Catalysts are the accelerators of many chemical reactions. Catalyst is an important additive to synthetic resin, and polyurethane is no exception. Polyurethane catalyst can shorten reaction time, improve production efficiency, selectively promote positive reaction and inhibit side reaction. In the production of many polyurethane products, catalyst is a commonly used additive, although the amount is small, the effect is great.
However, a small amount of inorganic compounds and organophosphorus oxygen compounds can be used as catalysts for polyurethane, but it is convenient to use and the catalysts commonly used in the synthesis of polyurethane and its raw materials are mainly tertiary amine catalysts (including its quaternary ammonium salts) and organometallic compounds
Big category.
Tertiary amine catalysts can be mainly divided into fatty amines, alicyclic amines, aromatic amines, alcohol amines and their ammonium salt compounds. Aliphatic amine catalysts include N, n-dimethylcyclohexamine, bis (2-dimethylaminoethyl) ether, triethylenediamine,N,N,N',N' -tetramethylalkylenediamine,N,N,N',N "-pentamethyldiethylenediamine, triethylamine,N, n-dimethylbenzylamine,N, n-dimethyl cetylamine,N, n-dimethylbutadiamine, etc.
Alicyclic amines include triethylenediamine, n-ethylmorpholine, n-methylmorpholine,N,N' -diethylpiperazine,N,N' -diethyl-2-methylpiperazine,N,N' -bis -(alpha-hydroxypropyl) -2-methylpiperazine, n-2-hydroxypropyl dimethylmorpholine, etc.
Alcohol amine catalysts are triethanolamine,N,N- dimethyl ethanolamine and so on. Alcohol is a kind of reactive catalyst which can be used in combination with other highly active catalysts. Triethanolamine is also a crosslinking agent for molding foams.
Aromatic amines are pyridine,N,N'- dimethylpyridine and so on.
The results show that (dimethylaminoethyl) ether (A-1) has high catalytic activity, and its reaction rate constant is 50% higher than that of triethylenediamine. In the comparative test of catalyst activity, the kinetic data of alcohol-isocyanate reaction were studied by using butanol-phenylisocyanate model reaction system, and the kinetics of water-isocyanate reaction was studied by using water and phenylisocyanate model reaction system. The solvent was toluene - dimethylformamide (90/10) at 25℃, and stannous caprylate was added in equal amount in each system.
Organometallic compounds include carboxylate, alkyl compounds, etc., the main metal elements are tin, potassium, lead, mercury, zinc, titanium, bismuth, the most commonly used organic tin compound. In polyurethane foams, tertiary amine and quaternary ammonium salt are generally used as catalysts. In addition, stannious caprylate is commonly used as catalyst for bulk foaming polyurethane soft foam by continuous process, potassium carboxylate is used to modify polyurethane hard foam by polyisocyanurate, and organotin compounds such as dibutyltin dilaurate can be used for a few hard foam, semi-hard foam and high rebound foam formulations.
The common amine trimer catalysts for rigid polyurethane foams are 2,4,6-(dimethylaminomethylphenol)
DMP-30), TMR series (such as trimethyl-N-2-hydroxypropyl caproic acid brand DABCO TMR), 1,3, 5-tri (dimethylaminopropyl) -hexahydrotriazine (PC Cat NP40, polycat41), etc.