Microporous polyurethane elastomer refers to a polyurethane elastic material with special micropores. Its relative density is 0.3~0.8, tensile strength is 5~10MPa, elongation at break is 250%~600%, tear strength is 10~48kN/m, and embrittlement temperature is -40~-20℃.
Features Of Polyurethane Microcellular Elastomer
The main physical properties of polyurethane microcellular elastomer exceed other foam or sponge materials with the same relative density. The raw materials for the manufacture of microcellular elastomers are oligomer polyols, polyisocyanates, chain extenders, catalysts, foam regulators or emulsifiers, foaming agents and pigments. Reaction injection molding (RIM) is used for continuous production. Polyurethane microcellular elastomer has good elasticity and large deformation, and can absorb large impact and vibration energy. Mainly used as anti-vibration rubber, air conditioner, filter material and sole. It is characterized by light weight, wear resistance, oil resistance and long service life.
Preparation Method of Polyurethane Microcellular Elastomer
A preparation method of a polyurethane microcellular elastomer, the production steps of which are as follows:
(1) Preparation of prepolymer: excess polyisocyanate reacts with polyol resin to form a prepolymer with a terminal-NCO group, the terminal-NCO group content of the prepolymer is greater than 10wt%, and the temperature of the prepolymer is kept at 35 ℃～60℃;
(2) Preparation of polyol resin mixture: The polyol in (1) is mixed with diol extender, water foaming agent, surfactant and delayed tertiary amine catalyst to prepare a polyol resin mixture, wherein diol The linking agent is 5wt% to 30wt% of the polyol; the amount of the delayed tertiary amine catalyst is 0.1wt% to 2wt% of the polyol resin mixture; the polyol is a polyether or polyester diol with a molecular weight of 800 to 4000. polyalcohol, the diol extender is ethylene glycol or diethylene glycol or propylene glycol or 1,4-butanediol or 1,6-hexanediol;
(3) Pouring: use a low-pressure foaming machine to mix and react the prepolymer with a temperature of 35°C to 60% and the polyol resin mixture in proportion, inject it into a mold with a temperature of 40°C to 80°C, and obtain polyurethane after curing. Microcellular elastomer.
Development Trend of Polyurethane Elastomers
Although the world polyurethane industry has entered a period of "stable development", it may also break this pattern with the application of some "high-tech" development results, and there may be a "leap forward" development. As foreign people think, with the "official debut" application of polyurethane tires, the "existing output" of polyurethane elastomers will increase several times, which is a development trend of polyurethane elastomers in the world.
Our domestic situation is very different from that of the world. No matter in terms of output or technical level, there is a big gap with foreign countries, and we are still far from the "peak". A lot of them have already existed abroad, but not in China. Those that are being researched and developed abroad have not yet started to be developed in China. At the same time, the development of the domestic economy has provided more application markets for polyurethane elastomers. Therefore, the potential domestic market is quite large, and the key lies in investing in development.
According to the current situation of my country's economy, the state does not invest, the industry has not formed a powerful economic entity group, and the development force is relatively weak. Therefore, multi-level application development can only be carried out according to the actual needs of the market, and most of them may be Refer to the modified application and development of foreign new technologies. To this end, the following development and development directions are provided.
Application Of Polyurethane Microcellular Elastomer
Polyurethane microporous elastomer auxiliary springs, car filter end caps, light shoe soles and other products were prepared with high activity polyether TEP-330N, modified MDI, ethylene glycol and TEP330. Using highly active polyether TEP330N to modify MDI, TEP330N, TPOP36/28, can produce a living microcellular elastomer model with a realistic image and a shape that can be changed at will. Using N-220 to modify MDI, TEP330N, TPOP36/28 can make boxing training targets, tumblers with high elasticity to vent private anger and other products. In a word, various types of polyurethane microcellular elastomer crystals with a density of 0.300-0.900 kg·m-3, a tensile strength of more than 2.5 MPa, and an elongation at break of more than 250% can be prepared as required.
