Method for preparing visible light self-repairing waterborne polyurethane coating material with double selenium bonds on main chain

Abstract

The invention discloses a method for preparing a visible light self-repairing waterborne polyurethane coating material with double selenium bonds on a main chain. The method comprises the following steps: firstly, preparing an isocyanate end capped polyurethane prepolymer with double selenium bonds on a main chain from raw materials of diisocyanate, dihydroxyethyl diselenide, macromolecule dihydric alcohol and dimethylolpropionic acid; secondly, adding triethylamine for neutralization, further adding a proper amount of deionized water for rapid emulsification, slowly adding a diamine chain extender which is diluted with water, and performing emulsification chain expansion under a condition that the rotation speed is greater than 1200r / min, thereby obtaining the visible light self-repairing waterborne polyurethane coating material with the double selenium bonds on the main chain. On the basis of the visible light reversibility characteristic of double-selenium dynamic covalent bonds, the waterborne polyurethane coating material with the double selenium bonds on the main chain is capable of achieving self-repairing of cracks and broken parts under radiation of gentle visible illumination, so that the service life of the material can be greatly prolonged, the potential safety hazard in use can be reduced, and a relatively long service life can be achieved for the waterborne polyurethane coating material. The waterborne polyurethane coating material with double selenium bonds on the main chain is applicable to coating of leather, textiles, paper, furniture, wall surfaces and the like, and has wide application prospects.

Description

technical field

[0001] The invention relates to a preparation method of water-based polyurethane, specifically, a preparation method of a visible light self-repairing water-based polyurethane coating material whose main chain contains a diselenium bond, and belongs to the fields of polymer synthesis technology and intelligent polymer materials. Background technique

[0002] During the use of materials, they will be affected by external factors such as heat, machinery and chemistry, and microcracks will be generated inside them, which will affect their service life and mechanical properties. In order to solve this kind of material damage that is difficult to detect macroscopically, material scientists are inspired by the self-healing process when organisms are damaged, and by imitating the principle of self-healing damage, self-healing materials came into being ( Nature , 2001, 409: 794-817.). Self-healing materials can sense changes in external environmental factors and res...