Novel self-repairing waterborne polyurethane as well as preparation method and application thereof

Abstract

The invention provides novel self-repairing waterborne polyurethane as well as a preparation method and application thereof. The novel self-repairing waterborne polyurethane is prepared from the following raw materials: 150 to 225 parts of polyisocyanate, 500 to 1200 parts of polyester polyol, 12 to 26 parts of dimethylolbutyric acid, 8 to 17 parts of furfuryl amine, 13 to 30 parts of bismaleimide and 2 to 6 parts of bifunctional non-waterborne chain extender. According to the novel self-repairing waterborne polyurethane material, a multifunctional cross-linking structure of dimethylolbutyric acid-furfuryl amine is introduced for modification, a hydrophilic group is connected to a cross-linking point, the water resistance of the formed material is improved through the steric hindrance effect, and the novel self-repairing waterborne polyurethane material has the advantages of being good in emulsion storage stability, high in water resistance, good in water resistance and the like. And the formed film has the advantages of high water resistance, high strength and self-repairing.

Description

technical field [0001] The invention belongs to the field of polyurethane materials, and in particular relates to a novel self-repairing water-based polyurethane and its preparation method and application. Background technique [0002] Water-based polyurethane emulsion uses water as the dispersion medium. In addition to the excellent mechanical and weather resistance properties of polyurethane, this material also has the advantages of safety, environmental protection, and simple process equipment. However, due to the presence of a large number of hydrophilic groups in waterborne polyurethane, its strength is poor, the material is more easily damaged, and its lifespan is low. [0003] Polyurethane (PU) is a general term for polymers containing repeated urethane groups in macromolecular chains. The hard and soft segments of polyurethane elastomers are chemically bonded. Because solvent-based polyurethane pollutes the environment and is toxic, the emergence of water-based poly...

AI Technical Summary

Problems solved by technology

However, due to low mechanical strength and short service life, water-based polyurethane must be modified

[0004] In the current self-healing polyurethane material, the self-healing group is usually to block the polyurethane prepolymer and introduce the self-healing group. For example, CN111349209A discloses a self-healing linear polyurethane and a preparation method thereof, comprising the following steps: taking polypropylene glycol and TDI, add DMF, heat to 40-60°C to dissolve to obtain a solution; add PPG to the obtained solution, raise the temperature to 65-85°C, and stir the reaction for 12-18min under the protection of nitrogen to obtain an intermediate; take out the intermediate body, lower the temperature to 0°C, add furfurylamine, react for 25-40min, return to room temperature, and obtain a polyurethane prepolymer; add bismaleimide to the obtained polyurethane prepolymer, After 24 hours of reaction, self-healing linear polyurethane was obtained, but the linear structure also led to the relatively general mechanical strength of the material

[0005] CN107001558A discloses that polyisocyanate compounds react with compounds containing active hydrogen groups to obtain self-healing polyurethane resins, but because of their linear structure, the introduction of hydrophilic groups will lead to an increase in the overall water absorption of the material

However, this method achieves high mechanical properties of the material by increasing the hydrogen bond density of the material through "hard segment locking" and "microphase separation control", which will inevitably lead to an increase in the water absorption of the material and limit the use of the material in high humidity conditions.

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