CN-121554914-B - Modified flame-retardant epoxy resin composite material and preparation method thereof

Abstract

The invention belongs to the technical field of high polymer materials, and relates to a modified flame-retardant epoxy resin composite material and a preparation method thereof. The invention provides a modified flame-retardant epoxy resin composite material, which is prepared from 100 parts by mass of bisphenol A type epoxy resin, 15-40 parts by mass of DOPO-MA grafted sodium alginate, 10-30 parts by mass of silica powder, 5-7 parts by mass of curing agent and 0.1-1 part by mass of accelerator, wherein the DOPO-MA grafted sodium alginate is synthesized by DOPO-MA and mercaptosodium alginate, and the molar ratio of DOPO-MA to mercaptosodium alginate is 1:1-1.2. Compared with the general epoxy resin, the mechanical property, the flame retardant property and the transparency of the modified flame retardant epoxy resin composite material provided by the invention are greatly improved.

Inventors

• Guo Haozheng
• HAN YICHEN
• ZHAI YUNHUI
• QIAO MINGTAO

Assignees

• 西安文理学院

Dates

Publication Date

20260512

Application Date

20260123

Claims (9)

1. 1. The method for improving the transparency of the modified flame-retardant epoxy resin composite material is characterized in that the raw materials comprise, by mass, 100 parts of bisphenol A type epoxy resin, 15-40 parts of DOPO-MA grafted sodium alginate, 10-30 parts of silica micropowder, 5-7 parts of curing agent and 0.1-1 part of accelerator; the DOPO-MA grafted sodium alginate is synthesized by DOPO-MA and sodium mercapto alginate, and the molar ratio of the DOPO-MA to the sodium mercapto alginate is 1:1-1.2; The preparation method of the DOPO-MA grafted sodium alginate comprises the steps of preparing sodium alginate solution, activating carboxyl in sodium alginate through EDC and NHS, adding cysteine, keeping the reaction pH at 4.0-5.0, reacting at room temperature for 3-5 h, then adjusting the pH to 6.0, continuing to react for 0.5-1 h, and then freeze-drying to prepare mercaptosodium alginate; the DOPO-MA grafted sodium alginate is additionally added to improve the flame retardant property, tensile strength and transparency of the modified flame retardant epoxy resin composite material; And heating bisphenol A epoxy resin, adding silicon micropowder and DOPO-MA grafted sodium alginate, uniformly mixing, cooling, adding a curing agent and an accelerator, continuously uniformly mixing, and finally pre-curing and curing to obtain the epoxy resin.
2. 2. The method for improving transparency of a modified flame retardant epoxy resin composite material according to claim 1, wherein fineness of the silica powder is not lower than 1250 mesh.
3. 3. The method of improving the transparency of a modified flame retardant epoxy resin composite of claim 1, wherein the curing agent is DMP-30.
4. 4. The method for improving the transparency of a modified flame retardant epoxy resin composite according to claim 1, wherein the accelerator is at least one selected from the group consisting of 2-ethyl-4-methylimidazole, 2, 4-dimethylimidazole and 1-methylimidazole.
5. 5. The method for improving transparency of a modified flame-retardant epoxy resin composite material according to claim 1, wherein a molar ratio of sodium alginate repeating structural units to EDC to NHS is 1:2:2, and a mass ratio of sodium alginate to cysteine is 1:2.
6. 6. The method for improving the transparency of a modified flame retardant epoxy resin composite material according to claim 1, wherein the bisphenol a type epoxy resin is heated to 110-140 ℃.
7. 7. The method for improving transparency of a modified flame retardant epoxy resin composite according to claim 1, wherein the cooling is to 40-50 ℃.
8. 8. The method for improving the transparency of a modified flame-retardant epoxy resin composite material according to claim 1, wherein the pre-curing temperature is 60-80 ℃ and the time is 1-3 hours.
9. 9. The method for improving the transparency of a modified flame-retardant epoxy resin composite material according to claim 1, wherein the curing temperature is 120-160 ℃ and the curing time is 1-3 h.

Description

Modified flame-retardant epoxy resin composite material and preparation method thereof Technical Field The invention belongs to the technical field of high polymer materials, and relates to a modified flame-retardant epoxy resin composite material and a preparation method thereof. Background The epoxy resin is used as thermosetting resin with excellent comprehensive performance, especially bisphenol A epoxy resin, has excellent mechanical performance, adhesion performance, electrical insulation performance, chemical corrosion resistance and molding processability, and is widely applied to various fields such as electronic and electrical packaging, composite material matrixes, adhesives, aerospace components, building materials and the like. However, the epoxy resin itself belongs to inflammable polymer materials, has low limiting oxygen index, is easy to generate melting and dripping phenomena in the combustion process, can release a large amount of toxic and harmful smoke, and is extremely easy to cause fire spreading and secondary hazard once a fire disaster occurs, and the inherent defect severely limits the further application of the epoxy resin in the key field with high requirements on flame retardance, so that the efficient and environment-friendly flame retardance modification of the epoxy resin is a core technical problem to be solved in the industry. At present, flame retardant modification means for epoxy resin are mainly divided into two main types of additive flame retardant modification and reactive flame retardant modification, wherein the additive flame retardant modification is a main stream mode of flame retardant modification for the epoxy resin at present due to simple and convenient process, controllable cost and wide applicability. Under the development trend of halogen-free environment-friendly industry, the phosphorus flame retardant gradually replaces the traditional halogen flame retardant by virtue of the characteristics of high flame retardant efficiency, low smoke toxicity release amount and excellent char formation effect, and becomes the preferable flame retardant for flame retardant modification of epoxy resin, wherein 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and derivatives thereof are representative varieties in the phosphorus flame retardant, phosphorus elements of the DOPO flame retardant exist in a ring structure, the heat stability is good, and the flame retardant process can effectively inhibit the combustion process of the epoxy resin by the synergistic effect of gas phase flame retardance and condensed phase flame retardance, so that the flame retardant grade of the epoxy resin is greatly improved. In the prior art, DOPO-MA is directly added into an epoxy resin matrix as a flame retardant, and a plurality of short plates still exist, wherein on one hand, DOPO-MA is a small molecular organic flame retardant, has poor compatibility with epoxy resin, is easy to agglomerate and precipitate under high addition amount, can not only lead to remarkable reduction of mechanical property and molding property of an epoxy resin composite material, but also cause uneven dispersion of the flame retardant, and cannot fully exert flame retardant efficiency, on the other hand, the small molecular DOPO-MA has strong mobility in an epoxy resin system, is easy to run off in a long-term use process, leads to the attenuation of the flame retardant property of the composite material, and meanwhile, the addition of DOPO-MA can negatively affect the optical property of the epoxy resin, so that the transparency of the epoxy resin composite material is reduced, and the application scenes of electronic packaging, optical devices and the like, which have requirements on light transmittance, are difficult to meet. Disclosure of Invention The invention aims to provide a modified flame-retardant epoxy resin composite material which has relatively excellent mechanical property, flame retardant property and transparency. In this regard, the present invention provides a modified flame retardant epoxy resin composite and a method of making the same to meet this need in the art. According to the invention, the sodium alginate solid product grafted with the DOPO structure is used as the flame retardant, so that the flame retardant property of the modified flame retardant epoxy resin composite material can be effectively improved and the transparency of the modified flame retardant epoxy resin composite material can be improved relative to DOPO-MA. On the one hand, the invention relates to a modified flame-retardant epoxy resin composite material, which comprises, by mass, 100 parts of bisphenol A epoxy resin, 15-40 parts of DOPO-MA grafted sodium alginate, 10-30 parts of silica micropowder, 5-7 parts of curing agent and 0.1-1 part of accelerator; the DOPO-MA grafted sodium alginate is synthesized by DOPO-MA and sodium hydrosulphide, and the molar ratio of the DOPO-MA to the sodium hydros