Solvent lignin-modified epoxy resin curing agent and preparation method thereof

A technology of epoxy resin curing and lignin, which is applied in the direction of epoxy resin coatings, coatings, etc., can solve the problems of water resistance, low flexibility, not harsh ratio, high price, etc., and achieve low manufacturing cost and low carbon development Economical, high-purity results

Inactive Publication Date: 2012-07-25
FUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005]3) Phenalkamine curing agent: This type of curing agent is generally formed by condensation of phenol, formaldehyde and polyamines. Compared with the above two types of curing agents, this type of curing agent The ratio of curing agent to epoxy resin is not strict, the curing speed is moderate, the mechanical properties and chemical resistance of the paint film are more excellent, and it can also be cured at low temperature, but the water resistance and flexibility are lower than polyamide curing agent
[0008]The raw material of traditional epoxy resin curing agent is petroleum or coal chemical industry products, the price is relatively high and consumes petroleum and coal resources

Method used

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  • Solvent lignin-modified epoxy resin curing agent and preparation method thereof
  • Solvent lignin-modified epoxy resin curing agent and preparation method thereof
  • Solvent lignin-modified epoxy resin curing agent and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] Example 1. Preparation of epoxy resin curing agent by enzymatically decomposing lignin directly with phenol, aldehyde and amine through Mannich reaction

[0042] Add 10g of enzymatic lignin and 40g of phenol into a three-necked flask with a reflux condenser and agitator, fill it with nitrogen and heat to dissolve, heat up and stir, and after complete dissolution, add 0.2g of concentrated sulfuric acid as a catalyst dropwise and continue to heat up to 85 ℃, reacted for 45min, then lowered the temperature to 60℃, added dropwise 30g triethylenetetramine and 20g formaldehyde respectively, after the dropwise addition was completed, raised the temperature and refluxed for 1.5h, and then vacuum dehydrated until 72g viscous phenalkamine epoxy resin was obtained. Resin curing agent.

Embodiment 2

[0043] Example 2. Demethylation of enzymatic lignin, and then Mannich reaction with phenol, aldehyde, amine to prepare epoxy resin curing agent

[0044] Install a stirrer, a reflux condenser and a thermometer on a 1000ml three-neck round bottom flask, and first enzymolyze 80g of

[0045] Add lignin to a three-neck round bottom flask, then add 3% (by weight) sodium hydroxide solution, heat up and stir until lignin dissolves, then add 3 g of sulfur, continue to heat slowly to a certain temperature, and stir at a constant temperature for a period of time time, then quickly cooled to room temperature, diluted with water, acidified to pH = 3 with sulfuric acid, extracted with ethyl acetate, separated into water phase and organic phase after centrifugation, separated into organic phase, evaporated under reduced pressure to remove the solvent, and then in Dry at room temperature for 24 hours and pulverize to obtain 76 g of tan demethylated lignin powder.

[0046] Add 20g ...

Embodiment 3

[0047] Example 3. Enzymatic hydrolysis of lignin and dimer acid condensation and grafting to obtain dimer acid modified lignin derivatives, and then react with phenols, aldehydes, and amines to prepare epoxy resin curing agents

[0048] Add 20g of enzymatic lignin, 0.04g of potassium persulfate, 0.04g of copper chloride inhibitor and 0.06g of ZrO in the three-necked round bottom flask 2 / SO 4 2+ Type solid superacid catalyst, then add 45ml of dioxane solvent, stir until the lignin is dissolved, then open the dropping funnel with 9g of dimer acid and 24ml-dioxane solution, control the rate of addition, add 15min After completion, heat up to 55°C and protect with nitrogen gas. After the dropwise addition, continue to react for 4.0 hours, and the acidity will not change. Suction filtration to recover the catalyst, after the reaction solution is cooled, slowly add the grafted product dropwise to 360ml of methanol, the reaction product precipitates out, centrifuge and stand ov...

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Abstract

The invention provides a solvent lignin-modified epoxy resin curing agent and a preparation method thereof. The epoxy resin curing agent is prepared from the following raw materials in part by weight: 10 to 30 parts of solvent lignin or derivative of the solvent lignin, 30 to 60 parts of phenol, 15 to 35 part of aldehyde, 20 to 45 part of ammine and 0.05 to 0.2 part of sulfuric acid catalyst. Thephenol-aldehyde-ammine epoxy resin curing agent is prepared by the Mannickreaction of the solvent lignin or derivative of the solvent lignin and the phenol, aldehyde and ammine. When the solvent lignin-modified phenol-aldehyde-ammine epoxy resin curing agent provided by the invention is used, petrochemical and coal chemical products can be replaced, the consumption of the petrochemical and coal chemical products is reduced, the cost of the epoxy resin is reduced, the lignin renewable resource in the waste from biorefinery is fully utilized, and the development of low-carbon economy is promoted.

Description

technical field [0001] The invention belongs to the field of new material development and preparation, and more specifically relates to a solvent-type lignin-modified epoxy resin curing agent and a preparation method thereof. Background technique [0002] Epoxy resin is an oligomer containing 2 or more epoxy groups in the molecule, with aliphatic, alicyclic or aromatic rings as the skeleton and capable of forming a thermosetting resin through the reaction of epoxy groups. It is an amorphous viscous liquid, which is plastic when heated, has no obvious melting point, becomes soft when heated, gradually melts and becomes sticky, insoluble in water, and will not harden itself, so it has almost no independent use value, only with curing agent The insoluble and infusible polymers that react to form a three-dimensional network structure have application value. When a certain amount of curing agent is added, they will gradually solidify and form a polymer with good adhesion, electri...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08G59/62C08G14/12C08G14/073C08H7/00C09D163/00
Inventor 程贤甦
Owner FUZHOU UNIV
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