Chitosan-modified low-temperature epoxy resin curing agent and preparation method thereof

Abstract

The invention discloses a chitosan-modified low-temperature epoxy resin curing agent. The curing agent is of a structural formula as following, wherein R is long-chain alkyl, m is an integer between 1 and 2, and n is any integer between 1 and 3. The invention further discloses a preparation method of the chitosan-modified low-temperature epoxy resin curing agent. The solid molecular structure of chitosan-modified low-temperature epoxy resin contains low-temperature active groups such as phenolic hydroxyl groups, thiocarbonyl groups and secondary amino groups, the chitosan-modified low-temperature epoxy resin can be cured normally even at low temperature of minus 5 DEG C as compared with E-44 epoxy resin, E-51 epoxy resin and E-20 epoxy resin with high curing activity, and the curing agent applied to epoxy resin paint is good in adhesion with base materials and resistant to impact. The curing agent is long lasting in sterilization, safe, environment friendly, simple in process and obvious in effect.

Description

technical field [0001] The invention relates to the field of preparation of an epoxy resin curing agent, in particular to a chitosan-modified low-temperature epoxy resin curing agent and a preparation method thereof. Background technique [0002] With the development of society, people pay more and more attention to the antibacterial properties of materials. Commonly used antibacterial materials mainly include inorganic metal mineral materials, organic heterocyclic antibacterial materials and natural antibacterial materials. Because natural antibacterial materials come from nature, are highly safe to the human body, and meet the requirements of green environmental protection, they have been welcomed by people in recent years. Chitosan is widely found in the shells of shrimps, crabs and insects, as well as in the cell walls of algae and fungi in nature. It is a natural polymer with rich sources and various biological activities. By introducing groups such as acyl groups, al...

AI Technical Summary

Problems solved by technology

[0003] In the field of epoxy resin curing agent, room temperature and heating curing agent can meet the requirements of most occasions, but in the field of low temperature fast curing, especially in low temperature environment (such as -5 ℃), the curing of aliphatic polyamine system is extremely slow, Even without curing, the cured product has low strength, poor toughness, poor chemical resistance and loss of use value

Moreover, the curing agent itself is highly toxic and irritating, which has a great impact on the human body and the environment.

[0004] Most of the low-temperature curing agents on the market are directly synthesized products of fatty amines and thioureas or low-molecular thiol compounds, which have obvious disadvantages: the products synthesized by the former contain a large amount of free amines, which have a strong smell and strong irritation. Extremely inconvenient; the latter low-molecular-weight thiol compound not only has a strong odor and poor temperature resistance, but also has a greater impact on the mechanical properties of the cured product

None of them are antimicrobial, which limits their range of applications

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