Preparation method of polyester dihydric alcohol and microcellular polyurethane elastomer

Abstract

The invention discloses a preparation method of a polyester dihydric alcohol. The preparation method comprises following steps: a mixed dihydric alcohol and a dicarboxylic acid are heated to 180 to 200 DEG C in inert atmosphere for condensation polymerization, wherein molar ratio of hydroxy of the mixed dihydric alcohol to carboxyl of the dicarboxylic acid is (1-2):1; the pressure of the reaction system is reduced to -0.099MPa, and temperature is increased to 230 DEG C when acid value is as high as 18 to 40mgKOH / g, and reaction is stopped with acid value is lower than 0.5mgKOH / g so as to obtain the polyester dihydric alcohol with a number-average molecular weight of 500 to 4000. The invention also provides a method used for preparing a polyurethane elastomer with the polyester dihydric alcohol. The obtained polyurethane elastomer possesses excellent hydrolysis resistance, low-temperature flexibility, and mechanical strength, and is mainly used for preparing high strength damping elements used for bearing dynamic fatigue, such as buffer damping elements of vehicles and bridge damper mass.

Description

technical field [0001] The present invention relates to a kind of polyester diol and preparation method thereof; The present invention also relates to the polyurethane microporous elastomer that utilizes aforementioned polyester diol to prepare hydrolysis resistance and low-temperature softness improvement, the product prepared by the method of the present invention is mainly used It is used as a high-strength damping element that withstands dynamic fatigue, such as buffer and shock absorbing elements for vehicles such as automobiles and bridge shock absorbing blocks. Background technique [0002] Polyurethane microcellular elastomer (PUR) is prepared by reacting polyester diol, polyether polyol and isocyanate in the presence of low molecular weight diol or water and other chain extenders and catalysts and other auxiliary agents. PUR using polyester diol has poorer hydrolysis and cold resistance than polyether polyol. On the other hand, PUR using polyether polyol has proble...

AI Technical Summary

Problems solved by technology

The microporous elastomer prepared by polyethylene adipate is easily hydrolyzed, even if a sufficient amount of anti-hydrolysis agent is added, its hydrolysis resistance cannot be effectively improved, and the cost of the corresponding manufacturing method is also increased; Although the hydrolysis resistance of the microcellular elastomer produced by butylene adipate has been improved to a certain extent, the obtained elastomer generally has an unacceptably high level of hardness at room temperature

At the same time, the polyester diol synthesized in this way has a high melting point which is unfavorable for processing.

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