Method for preparing chitin whisker modified waterborne polyurethane

Abstract

The invention relates to a method for preparing a chitin whisker modified polyurethane resin. The method is characterized by obtaining a polyurethane prepolymer by taking polyisocyanate and polyester polyol or / and polyether polyol as raw materials, then adding a small molecular chain extender and reducing the viscosity, and then adding chitin whiskers into waterborne polyurethane emulsion finished through emulsification to obtain chitin whisker modified waterborne polyurethane. In the method, the adding amount of the chitin whiskers is 1 to 5 percent of the total mass of three raw materials, namely the polyisocyanate, the polyester polyol or / and the polyether polyol, and the small molecular chain extender. The tensile strength and the Young modulus of a chitin whisker modified waterborne polyurethane material obtained by the method are both remarkably improved compared with waterborne polyurethane before the modification, and higher elongation at break is maintained. The method is simple in process and has readily available materials; moreover, the chitin whisker modified polyurethane resin is low in production cost, has the characteristics of environmental friendliness and biodegradability, and can be used as materials such as membranes, coatings, adhesives and the like.

Description

Preparation method of chitin whisker modified waterborne polyurethane technical field The invention belongs to the field of biological nanocomposite materials, and relates to a preparation method of modified polyurethane resin, in particular to a preparation method of chitin whisker modified waterborne polyurethane. Background technique Chitin is a polysaccharide natural polymer compound biosynthesized in animals and plants. Its output is second only to cellulose. The annual biosynthesis of chitin in nature is nearly 10 billion tons, which is a very rich natural resource. . Chitin is composed of four elements, C, H, O, and N, and its chemical formula is (C8H13NO5)n. Chitin is a polysaccharide connected by N-acetyl-2-amino-2-deoxy-D-glucose in the form of β-1,4 glycosidic bonds. According to the systematic nomenclature, chitin is called (1,4)-2- Acetylamino-2-deoxy-β-D-glucan. Chitin and its derivatives not only have good biocompatibility, low toxicity and biodegradabili...

AI Technical Summary

Problems solved by technology

The invention overcomes the technical defects that most current modification technologies can only rely on completely sacrificing the elongation at break to improve the tensile strength, and the preparation process of the modification technology is complicated, and provides a preparation of chitin whisker modified waterborne polyurethane method, the process is simple, the sources of raw materials are extensive, and it has the advantages of environmental protection and biodegradability

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