Polyurethane material and preparation method thereof

Abstract

The invention provides a polyurethane material which is obtained through a reaction of a first polyurethane prepolymer, a second polyurethane prepolymer and a chain extender. The first polyurethane prepolymer is obtained through a reaction of a polyhydroxy compound and one or two kinds of toluene diisocynate and benzene diisocyanate. The second polyurethane prepolymer is obtained through a reaction of a polyhydroxy compound and one or two kinds of 4,4'-diphenylmethane diisocyanate and naphthalene diisocyanate. The polyurethane material can be decomposed through the effect of water or microorganisms, and pollution is avoided; meanwhile, on the basis of the combination of the specific aromatic diisocyanate and the chain extender, the finally-obtained polyurethane material has the good strength and toughness.

Description

technical field [0001] The invention relates to the field of coating, in particular to a polyurethane material and a preparation method thereof. Background technique [0002] At present, my country's fertilizer consumption accounts for about 1 / 3 of the world's total fertilizer. However, according to relevant data, the utilization rate of the most widely used nitrogen fertilizer in my country is only 30% to 35%, which is quite different from the utilization rate of 50% to 55% in developed countries. The low utilization rate of chemical fertilizers leads to the need to fertilize multiple times in a crop growth cycle. Excess fertilizers accumulate in the rhizosphere of plants, which will not only damage the cell structure of plant roots, cause salt damage, cause crop yield reduction or even death, but also damage the soil structure. Lead to soil degradation and pollution of surface and groundwater bodies. Therefore, in the "Tenth Five-Year Plan" and "Eleventh Five-Year Plan",...

AI Technical Summary

Problems solved by technology

However, the development of coated slow-release fertilizers wrapped in polymer materials still has the following problems: 1. Organic polymer coated fertilizers have good nutrient release effects, but their nutrient release time still cannot be well matched with the crop fertilizer demand time 2. After the nutrients are released, the organic polymer shells remaining in the soil are difficult to degrade, and years of application will pollute the soil environment; 3. Most of the film-forming materials developed in China are mainly organic solvents, which are highly toxic , destroy the ozone layer and cause air pollution

In view of the above problems, the practical application of coated slow-release fertilizers is greatly limited.

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