Polyurethane modified natural rubber and preparation method thereof

Abstract

The invention discloses polyurethane modified natural rubber and a preparation method thereof, and the polyurethane modified natural rubber is prepared by mixing and vulcanizing the following materials in parts by mass: 40-90 parts of natural rubber, 5-30 parts of toluene isocyanate tar particles, 10-60 parts of polyurethane resin and 1-5 parts of a cross-linking agent. The polyurethane modified natural rubber disclosed by the invention is good in system compatibility and overall good in material performance, has good solvent resistance and wear resistance, and also has better rigidity while having good elasticity and elongation.

Description

technical field [0001] The invention relates to a modified natural rubber, in particular to a polyurethane modified natural rubber and a preparation method thereof. Background technique [0002] Natural rubber has excellent processing properties, physical and mechanical properties and dynamic properties, and has the advantages of low cost and easy acquisition. Polyurethane resin is mainly a block copolymerization product after the mixed reaction of polyisocyanate, polyol and chain extender. Because the structure contains carbamate and more polar ester groups, hydrogen bonds can be formed in and between polyurethane molecules. Alternate arrangements of polyols in the soft segment and isocyanates in the hard segment produce a microscopic phase-separated structure. These structural characteristics of polyurethane resin make it have excellent properties such as high strength, oil resistance, chemical corrosion resistance, aging resistance and wear resistance. Blending polyuret...

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Problems solved by technology

Blending polyurethane and natural rubber can be expected to obtain a modified product with complementary properties and excellent comprehensive properties. However, due to the large difference in polarity between the two, if they are directly mixed, the compatibility is poor, resulting in significantly lower product performance than expected

[0003] The Chinese patent literature with the publication number CN1771287A discloses a blend of polyurethane and rubber. Its specific preparation includes: first mixing the mixing type polyurethane and natural rubber in the internal mixer with the required ratio, and then The formulation of the formula is mixed with the required reinforcing agent, plasticizer, accelerator and filler during calendering. This method can obtain a product with better airtightness, but it does not propose a solution for the incompatibility of polyurethane and natural rubber. , only acceptable product elasticity and strength can be obtained

The Chinese patent document with the publication number CN110499016A discloses a mixing-type polyurethane and natural rubber blend vulcanizate and its preparation method. The natural rubber is modified with acid anhydride to obtain better compatibility with polyurethane. The method requires Use acid anhydride and natural rubber to modify in advance, the operation is cumbersome and the cost is high

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