Highly-water-resistant polyurethane emulsion having high biobased content, and its preparation method

Abstract

The invention discloses a vegetable oil based polyurethane emulsion containing a vegetable based carboxylic acid type hydrophilic monomer, and its preparation method. The emulsion is prepared through using the following substances, by weight, 27.59-38.06 parts of diisocyanate, 23.42-32.34 parts of castor oil, 0.1-0.2 parts of an organic tin catalyst, 6.68-10.87 parts of a salt forming reagent, 22.95-37.42 parts of the vegetable oil based carboxylic acid type hydrophilic monomer, and 160.0-216.70 parts of deionized water. The dry film of the vegetable oil based highly-water-resistant polyurethane emulsion has the characteristics of no whitening and no cracking after the immersion in water for 30 days, and has a water absorption rate of 5.6-12.1% after the immersion for 192h; and the highly-water-resistant polyurethane emulsion has the advantages of low cost, renewability, no environmental pollution, biodegradable property and the like because main used raw materials are renewable resources, can be used for coatings and adhesives as a resin, and can be especially used in occasions having a high water resistance requirement.

Description

technical field [0001] The invention relates to the field of polyurethane emulsions, in particular to polyurethane emulsions with high vegetable oil-based content containing vegetable oil-based carboxylic acid type hydrophilic monomers and a preparation technology thereof. Background technique [0002] Water-based polyurethane uses water as the dispersion medium. Compared with solvent-based polyurethane, it has the characteristics of environmental friendliness, safety and convenience in construction. It has become a research hotspot in the coatings and adhesives industry in recent years. But so far, the raw materials for the production of waterborne polyurethane are petrochemical products. With the depletion of petroleum resources, its sustainable development has been tested. It is a good solution to gradually replace petrochemical products with natural renewable resources such as vegetable oils. However, due to the limitations of the types of renewable resources used and ...

AI Technical Summary

Problems solved by technology

Dimethylolpropionic acid is a white crystalline powder, which has poor solubility in acetone and polyurethane prepolymers. During use, it is necessary to use N-methylpyrrolidone, N,N-dimethylformamide Polar, high boiling point solvents are used for dissolving, and these solvents cannot be removed in the later stage because of their high boiling points, and will eventually remain in the polyurethane film, affecting the performance of the coating film and the safety of use, while increasing the manufacturing cost of water-based polyurethane

[0004] The vegetable oil-based carboxylic acid type hydrophilic monomer in the present invention uses castor oil and 3-mercaptopropionic acid as raw materials, and the vegetable oil-based hydrophilic monomer can be prepared by one-step reaction and simple post-treatment. This vegetable oil-based hydrophilic monomer The synthesis of the body is rarely reported at present, and it does not need to be dissolved in an external solvent during use.