application of polyurethane catalysts in synthetic rigid plates
specifically, it involves a catalyst for the preparation of polyurethane and the application of the catalyst, which belongs to the field of polyurethane material synthesis technology.
polyurethane is a collective term for polymer compounds containing repeated carbamate groups on the main chain, which can be used to manufacture rubber, rigid and flexible foams, adhesives, coatings, paints and other products, and is widely used in construction, automobile, light industry, textile, petrochemical, metallurgy, electronics, national defense, medical, machinery and many other fields due to its excellent wear resistance, impact resistance, ultraviolet resistance and high and low temperature resistance.
polyurethane materials are made of polyisocyanates, polyols and other stabilizers as raw materials, at a certain temperature by catalytic reaction by catalysts, in the synthesis of polyurethane materials a type of catalyst commonly used in the synthesis of polyurethane materials is metal-organic compounds, such organometallic catalysts have long been lead and mercury organic compounds, but because lead and mercury are heavy metals, they are more harmful to the human body and will cause serious environmental pollution, and have been listed as prohibited products.
for this reason, an amine catalyst for the preparation of low-emission, recatalystically stable soft polyurethane foam body includes at least one reactive amine catalyst and at least one organokpotassium, zinc and/or tin compound, which has good catalytic activity. however, because the above-mentioned catalysts use tin compounds as a component of the catalyst, the organotin catalysts contain incomplete dibutyltin, etc., which are easy to lead to biological malformations or chronic poisoning, so they have been included in the list of controlled use by developed countries such as the european union. on the one hand, even if the reaction temperature is increased, the reaction speed can still be reduced and the reaction time is prolonged, on the other hand, if you want to achieve a reaction speed similar to that of tin-containing catalysts, you need to increase the amount of catalyst, for example, in the synthesis of synthetic leather slurry, the use of organic bismuth to completely replace dibutyltin dilaurate, the dosage will reach 4-5 times the original dosage; even so, the physical properties of the polyurethane materials catalyzed by it, such as tensile strength and tear strength, are significantly reduced, and furthermore, when using the formulation without tin compounds in the above literature, it is easy to turn the synthetic light-colored polyurethane material yellow. in addition, when the raw material formulation of synthetic polyurethane contains water, the organic compounds of bismuth or zinc will be inactivated by hydrolysis, which shortens the storage period of the composite.
therefore, the technical problem to be solved is that the catalyst without tin organometallic in the existing technology not only has low catalytic activity but also has poor catalytic performance of the catalytic synthesis of polyurethane materials, so as to provide an environmentally friendly polyurethane catalyst for the synthesis of rigid polyurethane materials with high catalytic activity and good physical properties of the prepared polyurethane material