Method for improving interfacial property and mechanical property of organic powder-polyurethane composite material

Abstract

The invention discloses a method for improving interfacial property and mechanical property of an organic powder-polyurethane composite material. The preparation process comprises the following steps:preparing a polyurethane composite solution, preparing a coagulating bath, performing knife coating on the polyurethane composite solution, and performing phase conversion molding and drying treatment. According to the method, a ternary mixed solvent prepared by blending a poor solvent of polyurethane, N,N-dimethylformamide and a solvent with polarity lower than that of the N,N-dimethylformamideis adopted on premise of not changing the preparation process of the organic powder-polyurethane composite material, so that unmodified organic powder can be well uniformly dispersed in the polyurethane solution, the original characteristics of organic powder particles are remained, and the mechanical property of the composite material is improved. The prepared organic powder-polyurethane composite material has excellent strength and strain property, is simple in preparation process, and has wide market requirement prospects in the fields of textile bionics, clothing and the like.

Description

technical field [0001] The invention relates to the technical field of composite materials, in particular to a method for improving the interface properties and mechanical properties of organic powder-polyurethane composite materials. Background technique [0002] Polyurethane is a polymer material composed of flexible segments and rigid segments, and its elasticity is between rubber and plastic materials. The polyurethane structure contains a large number of polar groups such as carbamate groups, ester groups and urea groups, which endow polyurethane elastomers with excellent wear resistance, high strength, good elasticity, low temperature resistance and heat resistance And other characteristics, and polyurethane materials also have excellent biocompatibility, making polyurethane one of the new materials that has attracted wide attention. The organic powder-polyurethane composite materials prepared by it are widely used in the field of polymer films. [0003] With the deve...

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Problems solved by technology

At present, the organic powder-polyurethane composite material prepared by traditional single solvent and single molding method, under the condition of high organic powder ratio, the interface between organic powder and polyurethane is poor, making the strength of polyurethane composite material Poor strain and strain; under the condition of low organic powder ratio, polyurethane composite materials can only reflect the performance of polyurethane bulk materials, and cannot well show the excellent surface properties of natural organic powder

In addition, by modifying the surface of organic powder, such as plasma modification and surface graft modification, the interface bonding force between organic powder and polyurethane material can be improved, thereby improving the mechanical properties of polyurethane composite materials. However, organic The surface modification of the powder will destroy the surface characteristics of the organic powder, and the effective use of the powder cannot be well realized

Aiming at the poor interface properties and tensile mechanical properties of organic powder-polyurethane composite materials at present, by changing the molding process of organic powder-polyurethane composite materials, the interface properties between organic powder and polyurethane are improved, and a A kind of organic powder-polyurethane composite film with high filling and high mechanical properties is of great significance

[0004] The patent application with the publication number CN105111490A discloses a method for preparing a high-strength, high-modulus and high-elasticity polyurethane film. This method uses ammonium salt as a coagulation bath, so that the ammonium salt molecules in the polyurethane film after film formation and the amorphous region molecules in the polyurethane The micro-crosslinked structure formed in the form of hydrogen bonds, or the formation of nano-needle structures and nano-spherical structures in the pores of the polyurethane film, can simultaneously increase the tensile stress and strain of the polyurethane film, but its disadvantage is that this The composite membrane does not have good hydrophilic and moisture permeability properties

[0005] In the open magazine "Technical Textiles" in October 2006, the 8th issue titled "The Effect of Ultrafine Wool Powder on the Waterproof and Moisture Permeability of Polyurethane Membranes", the mechanical properties and waterproof permeability of polyurethane membranes with different contents of wool powder were studied. The influence of wet performance, the solvent used in this article is a single N, N-dimethylformamide, and the film-forming method used is the immersion precipitation method. The prepared polyurethane / wool powder composite film has certain moisture permeability , but its shortcoming is that the breaking strength and elongation at break of the composite film are low

[0006] In the article titled "Silk Fibroin Powder and Medical Polyurethane Sol Blending-Preparation and Properties of Hot-pressed Blending Film" of the open magazine "Macromolecule Materials Science and Engineering" in August 2011, the 8th issue, solution blending and thermal compression were used. Polyurethane composite films with different silk fibroin powder contents were prepared by pressing method, and the prepared polyurethane composite films had a certain breaking strength, but the disadvantage was that when the silk fibroin powder content was large, the polyurethane / silk fibroin composite film The elongation at break is much lower than that of polyurethane film, which limits the application of polyurethane / silk fibroin composite film

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