Catalysts are the accelerators of many chemical reactions. Catalyst is an important additive for synthetic resins, and polyurethane is no exception. Polyurethane catalystShorten reaction time, improve production efficiency, selectively promote positive reactions and inhibit side reactions. In the production of many polyurethane products, catalyst is a commonly used additive. Although the dosage is small, it has a great effect.
Although a small amount of inorganic salt compounds, organic phosphorus oxygen compounds, etc. can be used as catalysts for polyurethane, they are easy to use and commonly used catalysts in the synthesis of polyurethane and its raw materials mainly include tertiary amine catalysts (including their quaternary ammonium salts). ) and organometallic compounds.
Tertiary amine catalysts can be mainly divided into aliphatic amines, alicyclic amines, aromatic amines, alcohol amines and their ammonium salt compounds. Aliphatic amine catalysts include N,N-dimethylcyclohexylamine, bis(2-dimethylaminoethyl)ether, triethylenediamine, and N,N,N’,N’-tetramethylalkylene diamine, N,N,N’,N”-pentamethyldiethylenetriamine, triethylamine, N,N-dimethylbenzylamine, N,N-dimethylhexadecylamine, N,N-dimethylbutylamine, etc.
Alicyclic amines include triethylenediamine, N-ethylmorpholine, N-methylmorpholine, N,N’-diamine Ethylpiperazine, N,N’-diethyl-2-methylpiperazine, N,N’-bis-(α-hydroxypropyl)-2-methylpiperazine, N-2-hydroxypropyl Dimethylmorpholine etc.
Alcoholamine compound catalysts include triethanolamine, N,N-dimethylethanolamine, etc. Alcohol catalyst is a type of reactive catalyst that can be used in conjunction with other highly active catalysts. Triethanolamine is also a cross-linking agent for molded foams. Aromatic amines include pyridine, N,N’-dimethylpyridine, etc.
Research data shows that (dimethylaminoethyl) ether (A-1) has high catalytic activity, and its reaction rate constant is higher than triethylene Diamine is 50% higher. In the activity comparison test of the catalyst, the butanol-phenyl isocyanate model reaction system was used to study the alcohol-isocyanate reaction kinetic data, and the water and phenyl isocyanate model reaction system was used to study the water-isocyanate reaction kinetics. The solvent was 25°C toluene-bis Methylformamide (90/10), add an equal amount of stannous octoate to each system.
Organometallic compounds include carboxylates, alkyl compounds, etc. The main metal elements contained are tin, potassium, lead, mercury, zinc, titanium, Bismuth Temple, the most commonly used organotin compound. In polyurethane foam, tertiary amines and quaternary ammonium salts are generally used as catalysts. In addition, stannous octoate is a commonly used polyurethane catalyst for continuous block foaming of soft polyurethane foam, potassium carboxylate is mostly used for polyisocyanurate-modified rigid polyurethane foam, and organotin compounds such as dibutyltin dilaurate can be used for A few hard foam, semi-hard foam and high rebound foam formulations.
