Hyperbranched aqueous polyurethane and preparation thereof

Abstract

The invention provides hyper-branched waterborne polyurethane and a preparation method thereof, and relates to hyper-branched waterborne polyurethane obtained by the method and application thereof. The method comprises the following steps: 1) diisocyanate containing two isocyanate radicals reacts with organic acid containing one carboxyl group and two hydroxyl radicals, so as to obtain a reaction intermediate which contains two isocyanate groups and one carboxyl group on average and is called A1 for short; 2) the A1 reacts with a monomer containing one amino group and two (or more than two) hydroxyl radicals, so as to obtain a reaction intermediate which contains one isocyanate group, one carboxyl group and two (or more than two) hydroxyl radicals on average and is called A2 for short; and 3) the A2 is heated to enable the isocyanate group to react with the hydroxyl radicals, so as to obtain a hyper-branched waterborne polyurethane product containing hydrophilic carboxyl group structures, and then the product is separated and dried so as to obtain a hyper-branched waterborne polyurethane solid product in the shape of white powder. The obtained hyper-branched waterborne polyurethane simultaneously contains a large number of carboxyl groups and hydroxyl radicals, can be neutralized with alkaline matter and then dissolved in water, is suitable to be used as environment-friendly waterborne coatings, waterborne adhesives, phase compatibilizers, rheological additives, thixotropic agents, nucleating agents, active compound carriers or catalyst carriers and the like, and has wide application prospects.

Description

technical field [0001] The invention relates to a method for preparing hyperbranched water-based polyurethane, and to the hyperbranched water-based polyurethane obtained by the method and its application. Background technique [0002] The concept of highly branched macromolecules was first proposed by Flory in 1952, who pointed out the possibility of preparing highly branched polymers by polymerizing multifunctional monomers. As long as the monomer is AB x (X≥2) type, A and B are both reactive functional groups, which can produce a hyperbranched structure. In this structure, chain growth occurs between two different functional groups without additional protection steps. At the same time, he also made some speculations about its nature. [0003] Hyperbranched macromolecules (Hyperbranched polymer) structure is similar to dendritic. Kim first applied for the first patent (U.S.Pat.4857630, 1987.) on the preparation of hyperbranched polymers in 1987, and announced this achie...

AI Technical Summary

Problems solved by technology

But none of these hyperbranched polyurethanes are water soluble and cannot be dispersed in water