Prepolymer, polyurethane emulsion prepared therefrom for carbon fibers, and applications thereof

Abstract

The invention discloses a prepolymer, which comprises the following components: (A) polyether glycol; (B) aromatic diisocyanate; wherein the weight ratio of the component (A) to the component (B) is 5.65:1 to 9.43:1; polyurethane emulsion for carbon fibers comprises the following components in parts by weight: 66.5 to 104.3 parts of prepolymer, 45 to 55 parts of organic solvent, 66 to 184 parts of deionized water, and 2 to 14 parts of processing auxiliary agent. The preparation method comprises the following steps: adding polyether glycol into a reactor, carrying out a water removing treatment at the temperature of 120 DEG C for 1 hour, cooling to 50 DEG C, stirring and heating to 70 DEG C in an oil-bath; then adding aromatic diisocyanate into the reactor, carrying out a reflux reaction for 2 hours under the protection of nitrogen gas, adding an organic solvent into the reactor, and cooling to the 40 DEG C so as to obtain the prepolymer; adding a processing auxiliary agent, dissolving the agent with an organic solvent, then adding the solution into the prepolymer, carrying out the reactions for 1 hour, then adding water to carry out emulsion reactions for 30 minutes, and finally carrying out reduced pressure distillation to remove the organic solvent so as to obtain the target product. The obtained polyurethane emulsion can reduce the surface tension of carbon fibers, improves the wettability and bundling of carbon fibers, reduces the broken filament rate, and can be applied to the fields of automobile, medicine, food processing, and chemical engineering.

Description

technical field [0001] The invention relates to the technical field of carbon fiber surface modification, in particular to a prepolymer, a polyurethane emulsion for carbon fiber prepared therefrom and an application thereof. Background technique [0002] Carbon fiber has the characteristics of high strength, high modulus, electrical conductivity, thermal conductivity, high temperature resistance and corrosion resistance. Its main purpose is to be used as a reinforcing material, compounded with a resin matrix, to prepare high-performance composite materials, and to replace traditional steel and other materials. Applications in defense, aerospace and other fields. Due to the inertness of the surface of carbon fiber, it is difficult to combine with other matrix materials to prepare composite materials with good interface properties, which largely limits its excellent performance. For this reason, it is necessary to modify the surface of carbon fiber. At present, there are a l...

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Problems solved by technology

Due to the inertness of the surface of carbon fiber, it is difficult to combine with other matrix materials to prepare composite materials with good interface properties, which largely limits its excellent performance.

For this reason, it is necessary to modify the surface of carbon fiber. At present, there are a large number of patent reports on the modification method of carbon fiber in domestic carbon fiber production. Its conductivity and compatibility with metals can be used to prepare C / metal composite materials; patents CN101413209B and CN101413210B use plasma technology to coat inorganic materials such as nano-sol and silica on the surface of carbon fibers to improve the phase between carbon fibers and inorganic materials. Capacitance; Chinese patents CN102321976A, CN101858038B, CN101880967B and other patents use the preparation of sizing agents to modify the surface of carbon fibers. The carbon fiber after sizing is loose and has a large amount of hairiness. It is mainly used to strengthen epoxy thermosetting resin. The modification method of carbon fiber in the above patent documents limits the application field of carbon fiber to a certain extent.

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