A kind of preparation method of water-based flame-retardant self-healing polyurethane based on modified graphene

Abstract

The invention discloses a preparation method of water-based flame-retardant self-healing polyurethane based on modified graphene. The method is as follows: first, the graphene oxide covalently modified by aminocyclotriphosphazene and isocyanate silane is ultrasonically crushed, then reacted with high molecular weight diol, hydrophilic chain extender and diisocyanate, and then capped by diselenediol After neutralization and emulsification, water-based self-healing polyurethane containing diselenium bonds is added to obtain the water-based flame-retardant self-healing polyurethane emulsion. By reducing the size of graphene oxide and modifying the water-based polyurethane chain, its water dispersion stability, dispersion uniformity and compatibility in the film are improved, thereby improving the mechanical strength of the film; and nitrogen phosphorus silicon modification further improves the flame retardancy Performance; at the same time, the double selenium bond endows the material with good room temperature light self-healing function. The method provided by the invention is environmentally friendly, and the prepared material has high mechanical properties and excellent flame-retardant self-repair function, and can be applied to many fields such as leather finishing and fabric finishing.

Description

technical field [0001] The invention relates to a preparation method of water-based flame-retardant self-healing polyurethane, in particular to the preparation of water-based flame-retardant self-healing polyurethane based on nitrogen-phosphorus-silicon-modified nano-graphene oxide, and belongs to the fields of leather finishing and fabric finishing. Background technique [0002] Polyurethane is a polymer material with light weight, good mechanical properties, chemical stability, corrosion resistance, easy processing, and high resilience. Therefore, it has been widely concerned by researchers since it was developed by Bayer in 1937. After more than 80 years of development, it has been widely used in the fields of textile, leather, construction, automobile, aerospace and transportation. However, most polyurethanes are extremely flammable, which is determined by their chemical structure and elemental composition, which greatly restricts their practical applications in many fie...

AI Technical Summary

Problems solved by technology

However, this method only uses a flame retardant to modify graphene oxide, which has a limited improvement in the flame retardant function of the material. Therefore, introducing multiple flame retardant components on graphene oxide to synergistically flame retardant has a better flame retardant effect on the material. promotion

[0010] For example, Chinese patent (CN109735094A) discloses a preparation method of nitrogen-phosphorus-silicon-modified graphene / self-healing polyurethane flame-retardant composite material, which is composed of polyethyleneimine, 9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide and isocyanatosilane covalently modify graphene oxide and in-situ polymerize it with self-healing polyurethane containing diselenium, and obtain a good flame retardant effect, but the reaction system is The solvent system has not been water-based, and it is difficult to meet the growing environmental protection requirements

At the same time, the modified graphene oxide synthesized by this method is not grafted with polyurethane chains with self-healing function, so that the modified graphene oxide cannot participate in self-healing, and the content of self-healing components is reduced, which obviously affects the self-healing efficiency. The mechanical properties of the back film cannot be guaranteed, which greatly limits its application

[0011] For example, Chinese patent (CN111607319A) discloses a self-healing waterborne polyurethane / rGO@PDA composite material and its preparation method and application. It is obtained by ultrasonically blending polydopamine on graphene oxide and self-healing waterborne polyurethane. Certain water dispersibility and near-infrared irradiation self-healing ability, but its compatibility with waterborne polyurethane is not good, and the obtained composite material does not have flame retardancy, and the practical application range is limited

[0012] For example, Chinese patent (CN110643272A) discloses a graphene oxide modified water-based polyurethane thermally conductive flame-retardant antistatic coating film-forming agent and its preparation method, which is obtained by in-situ polymerization of hydroxyl-terminated hyperbranched graphene oxide and water-based polyurethane. It has good electrical conductivity and flame retardancy, but it does not have self-healing function, which limits its service life, and its water dispersibility is not good, emulsion stability is poor, and storage time is short, both of which limit its applicability