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Preparation method of degradable primary amine curing agents

A curing agent and primary amine technology, applied in the field of preparation of degradable primary amine curing agent, can solve the problems of strong acid corrosion, fiber shortening, difficult post-processing, etc.

Active Publication Date: 2013-12-11
ADESSO ADVANCED MATERIALS WUXI CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At the same time, the cross-network structure of cured epoxy makes it particularly difficult to remove, recycle and reuse
The cross-linking reactions that typically occur with polyamines compounded with epoxy resins are inherently irreversible, therefore, the material cannot be remelted, reshaped without loss, or easily dissolved
Fiber-reinforced composite materials can be prepared by combining thermosetting epoxy resin matrix with fibers. The cured epoxy resin is difficult to decompose and melt. Correspondingly, fiber-reinforced epoxy resin composite materials are not easy to recycle.
[0006] At present, there are roughly the following recycling processes for fiber-reinforced composite materials: 1. High-temperature thermal degradation (Thermochimica Acta2007 (454): 109-115), which can be recycled to obtain clean fillers and fibers, but it needs to be carried out under high temperature conditions. High requirements on equipment; 2. Fluidized bed (Applied surface science2008(254): 2588-2593) also requires high temperature to recover clean fibers; 3. Supercritical fluid (water (Materials and design2010(31): 999- 1002), alcohol (Ind.eng.chem.res.2010 (49): 4535-4541), carbon dioxide (CN102181071), etc.) have also achieved the degradation of the redox resin system, but they are all in the laboratory stage, far from the real There is still a long way to go for industrialization; 4. Use nitric acid (Journal of applied polymer science, 2004(95): 1912-1916) to degrade epoxy resin and recover fibers with clean surfaces, but strong acids such as nitric acid are highly corrosive , high requirements on equipment, low operational safety, high recycling cost, and difficult post-processing
In general, these methods have their limitations to varying degrees, such as fiber shortening, performance degradation, environmental pollution, and high recycling costs.

Method used

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  • Preparation method of degradable primary amine curing agents

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0141] Embodiment 1: the synthesis of two (2-chloroethoxy) methane

[0142]

[0143] Method 1: Put 346 grams of toluene and 800 grams of 2-chloroethanol into the reaction flask in sequence, and put 164 grams of paraformaldehyde and 4.8 grams of p-toluenesulfonic acid under stirring, and the system is heated up slowly, and the Dean-Stark is refluxed to separate water. When no water droplets were separated, the reaction was extended for another 1 hour, which was the end of the reaction. After the reaction, lower the temperature to below 40°C, add an appropriate amount of sodium carbonate to the reaction bottle, adjust the pH value of the reaction liquid system to be close to neutral, then concentrate the reaction liquid under reduced pressure, recover all the toluene, vacuum distill the residue, and collect 60-75 °C / 200pa, about 753 grams of bis(2-chloroethoxy)methane was obtained, and the yield was 87.6%.

[0144] Method 2: Put 346 grams of toluene and 800 grams of 2-chloro...

Embodiment 2

[0145] Embodiment 2: the synthesis of 2,2-bis(2-chloroethoxy)propane

[0146]

[0147] 20 grams of 2-chloroethanol, 14.2 grams of 2,2-dimethoxypropane, 0.11 grams of p-toluenesulfonic acid, and 0.35 liters of toluene were mixed at room temperature, DEAN-STARK was refluxed to separate water, and reacted for 20 hours. Concentrate under reduced pressure at room temperature to recover toluene, and collect the residue with a boiling range of 53-55°C under vacuum at 150 Pa to obtain 13 g of 2,2-bis(2-chloroethoxy)propane.

Embodiment 3

[0148] Embodiment 3: the synthesis of curing agent 1

[0149]

[0150] Curing agent I

[0151] Curing agent I put 960 grams of concentrated ammonia water and 150 grams of ammonium chloride into the autoclave, stir and dissolve, then add 5 grams of bis(2-chloroethoxy)methane prepared in Example 1, then heat up to 120 ° C, Stir the reaction for 3 hours, and check the end point of the reaction by TLC. After the reaction, concentrate most of the solution under reduced pressure, transfer the residual solution to a reaction bottle, and adjust the pH to ≥ 10 with solid sodium hydroxide solution at a temperature below 25°C, and then use chloroform to and ethanol (volume ratio 3:1) mixed solvent 300 ml, extract the aqueous phase 3 times, combine the organic phase, dry the organic phase with anhydrous sodium sulfate, filter, wash the filter cake once with a small amount of solvent, and concentrate the filtrate to dryness , Distilled under reduced pressure to collect under 70Pa vacuu...

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PUM

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Abstract

The invention provides a preparation method of four degradable primary amine curing agents. The preparation method comprises the following steps: reacting raw materials with ammonia or ammonia water to generate primary amine curing agents, carrying out a Gabriel reaction of the raw materials to generate o-dicarboximide or phthalimide group-containing compounds, hydrolyzing or hydrazinolyzing the compounds to obtain crude products, and purifying and refining the crude products to obtain the primary amine curing agents. Epoxy resins and fiber reinforced composite materials prepared through using the primary amine curing agents obtained in the invention have a good degradation performance, are friendly to environment, and are environmentally friendly materials.

Description

technical field [0001] The invention relates to the technical field of epoxy resin curing agents, in particular to a preparation method of a degradable primary amine curing agent. Background technique [0002] Epoxy resin is widely used in the fields of composite materials, castings, electronic appliances, coatings and adhesives due to its excellent physical and mechanical properties, electrical insulation properties, bonding properties with various materials and its flexibility in use and processing , plays an important role in various fields of the national economy. [0003] Epoxy resin curing agent is an additive that chemically reacts with epoxy resin to form a network-like three-dimensional polymer, making the linear resin into a tough solid body. As a thermosetting resin, epoxy resin requires a special curing agent when curing. There are many kinds of curing agents, such as basic curing agents, including aliphatic diamines and polyamines, aromatic polyamines, other n...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C217/08C07C213/02C07D317/28C08G59/50
Inventor 覃兵李欣梁波
Owner ADESSO ADVANCED MATERIALS WUXI CO LTD
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