Diisocyanate having fluorine-containing branched chain, preparation method and application thereof

Abstract

The invention discloses diisocyanate having fluorine-containing branched chain, a preparation method and application of diisocyanate having fluorine-containing branched chain in waterborn fluorine-containing polyurethane. The diisocyanate is prepared from (by weight parts) 6-10 parts of trimethylolpropane, 100-120 parts of isophorone diisocyanate, 5-20 parts of 2,2,2-trifluoroethanol and 0.06-1.8 parts of catalyst by stirring trimethylolpropane at 100-120 DEG C under vacuum for dehydration, adding isophorone diisocyanate and 0.03-0.9 parts of catalyst under the protection of nitrogen, reacting at 80-85 DEG C for 2-3 h, adding 2,2,2-trifluoroethanol and the rest of catalyst, and further reacting at 80-85 DEG C for 2-3 h. The diisocyanate is used for preparing waterborn fluorine-containing polyurethane, and the obtained waterborn fluorine-containing polyurethane has flexibility, elasticity, and good tensile strength, elongation at break, and contact angle with water.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and in particular relates to a side chain fluorine-containing diisocyanate, a preparation method thereof and an application in water-based fluorine-containing polyurethane. Background technique [0002] Due to its low surface energy, excellent chemical stability, heat resistance, pollution resistance and atmospheric aging resistance, fluorine-containing polyurethane has become an excellent coating film-forming material. Coatings are widely used. [0003] At present, fluorine-containing diisocyanates are mainly fluorine-containing structures in the main chain of the molecule. Due to the electron-withdrawing effect of fluorine, the adjacent -NCO groups have poor reactivity, that is, low activity. Therefore, the water-based polyurethane prepared from it has low molecular weight and poor flexibility. , poor solubility, and high brittleness, thus greatly limiting their practical application...

AI Technical Summary

Problems solved by technology

[0003] At present, fluorine-containing diisocyanates are mainly fluorine-containing structures in the main chain of the molecule. Due to the electron-withdrawing effect of fluorine, the adjacent -NCO groups have poor reactivity, that is, low activity. Therefore, the water-based polyurethane prepared from it has low molecular weight and poor flexibility. , poor solubility and high brittleness, thus greatly limiting their practical application

[0004] Moreover, the current method for preparing fluorine-containing diisocyanates is mainly prepared by reacting fluorine-containing diamines with phosgene. This preparation method is slow in reaction, and there are insurmountable side reactions at the same time and the yield is very low.

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