Castor oil derivative-based aqueous polyurethane preparation method

Abstract

The present invention provides a castor oil derivative-based aqueous polyurethane preparation method, which comprises: S1, preparing a castor oil derivative by using castor oil as a raw material, wherein the castor oil derivative comprises, by weight, 5-30 parts of castor oil, 0.1-2 part of hydrogen chloride, 5-30 parts of ethanol, 6-40 parts of an alkali solution, and 20-80 parts of saturated salt water; and S2, preparing waterborne polyurethane by taking the castor oil derivative as a waterborne chain extender, wherein the waterborne polyurethane comprises the following components in parts by weight: 5-40 parts of a solvent, 5-30 parts of MDI-100, 5-30 parts of polyol, 1-20 parts of the castor oil derivative, 1-10 parts of dihydric alcohol, 0-15 parts of TEA and 30-90 parts of water. According to the preparation method, castor oil is used as a raw material to prepare the water-based chain extender, then the chain extender is used for preparing the water-based polyurethane resin, andthe prepared water-based polyurethane resin has the characteristic of high alcohol tolerance, is beneficial to reducing the viscosity of a prepolymer, is easy to emulsify, and accelerates the volatilization speed of a water-based flat product while ensuring environmental protection.

Description

technical field [0001] The invention relates to the technical field of organic polymer synthesis, in particular to a method for preparing waterborne polyurethane based on castor oil derivatives. Background technique [0002] With the advancement of national environmental protection policies, chemical products containing volatile organic compounds (VOC) will be strictly restricted. Therefore, more and more solvent-based products will be transformed into water-based products. [0003] As one of the water-based modified products, water-based polyurethane resin (PUD) is mostly anionic, and the most commonly used preparation method is to use dimethylol propionic acid (DMPA) in the synthesis to make the carboxyl group into a salt in an alkaline solution For emulsification, dimethylolbutyric acid (DMBA) is also used as a raw material. [0004] The problem with these preparation methods is that DMPA or DMBA must be dissolved in strong polar high-boiling point solvents, such as NMP,...

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Problems solved by technology

[0004] The problem with these preparation methods is that DMPA or DMBA must be dissolved in strong polar high-boiling point solvents, such as NMP, DMF, etc., but these high-boiling point solvents cannot be removed, so that the final PUD product contains harmful substances and volatilizes more slowly during processing and use

In addition, DMPA or DMBA is derived from petrochemical processing, which is not a low-carbon product in itself, does not have the advantage of sustainable development, and the price is relatively high

[0005] Another kind of preparation method is to bring metal ions without adding salt agent, such as sodium diaminosulfonate and sulfonate polyols. These products are not widely used and the price is higher.

[0006] In addition, as far as PUD products are concerned, conventional oil-based resins for leather are mostly synthesized with MDI, while water-based resins are mostly synthesized with TDI and IPDI. The change of materials will lead to the decline of expansion force and temperature resistance, which will affect the normal use of PUD.