Light-colored cardanol alkyl ether epoxy curing agent and preparation method thereof

Abstract

The invention provides a light-colored cardanol alkyl ether epoxy curing agent and a preparation method thereof, the cardanol alkyl ether epoxy curing agent prepared by the method, and a cured object formed by the curing agent and an epoxy resin. The preparing method comprises the steps of: mixing 1 mol of cardanol alkyl ether and 1-3 mol of polyamine; then adding 1- 3 mol of formaldehyde in batch, and controlling a reaction temperature between 80 DEG C and 90 DEG C and reacting for 4 hours; next, heating to 100-120 DEG C and evaporating water generated by reaction; at last, retaining at 80-120 DEG C, distilling at a reduced pressure till no moisture is evaporated; and obtaining the cardanol alkyl ether epoxy curing agent through Mannich reaction. The curing agent obtained by the invention is relatively light in color and non-discoloring after long-time storage; in addition, mixture of the curing agent and the epoxy resin encounters phase separation in curing, so that the impact strength of the cured object is improved, and the flexibility of material is reinforced.

Description

technical field

[0001] The invention relates to a preparation method of an epoxy resin curing agent, in particular to a light-colored cardanol alkyl ether epoxy curing agent capable of curing-induced phase separation and a preparation method thereof. Background technique

[0002] Cardanol is a cashew nut shell cardanol is a natural biophenol with a 15-carbon long carbon chain in the meta-position of a monohydric phenol structure. Cardanol is non-toxic and non-corrosive, which is different from petroleum phenol, which is highly corrosive and highly toxic. It is more friendly to the environment and human body. Its structure is as follows:

[0003]

[0004] where n is 0, 1 or 2.

[0005] Cardanol has a wide range of uses and can be used in phenolic resins, epoxy resin curing agents, surfactants and demulsifiers. However, the phenolic hydroxyl group of cardanol is extremely easy to be oxidized by air into quinone derivatives, resulting in a very dark color of cardanol or d...

Examples

preparation example Construction

[0027] The preparation method of this light-colored cardanol alkyl ether epoxy curing agent is: 1 mole of cardanol alkyl ether and 1-3 moles of polyamines are mixed, then 1-3 moles of formaldehyde are added in batches, and the reaction temperature is controlled at React at 80-90°C for 4 hours, then heat up to 100-120°C to distill off the water generated by the reaction, and finally keep the temperature at 80-120°C and distill under reduced pressure until no water is evaporated, and then obtain cardanol alkyl ether through Mannich reaction epoxy curing agent.

[0028] In the preparation method of the above-mentioned light-colored cardanol epoxy curing agent, the structure of the cardanol alkyl ether used wherein is as follows:

[0029] where m is an integer from 0 to 22, and where n is 0, 1 or 2.

[0030] In the preparation method of the above-mentioned light-colored cardanol epoxy curing agent, wherein the polyamine used can be ethylenediamine, hexamethylenediamine, dihexyltr...

Embodiment 1

[0034] Mix 316g of cardanol methyl ether (1 mole, Nanjing Science and Technology Development Corporation of Institute of Forestry and Chemical Engineering) and 309g of diethylenetriamine (3 moles, Suzhou Xinxin Chemical Co., Ltd.) into a 2000 Add 243g of 37% formaldehyde solution (3 moles, Nanjing Chemical Reagent Factory) in batches within 0.5 hours, control the reaction temperature between 80-90°C for 4 hours, then raise the temperature to 100-120°C The water generated by the reaction was steamed under pressure, and the final temperature was kept at 80-120° C. under reduced pressure until no water was evaporated, and 207 g of water was evaporated. Obtain 641g of light yellow oily cardanol methyl ether epoxy curing agent, the amine value is 383mg / g, and the yield is 97%.

Embodiment 2

[0036] Mix 358 g of cardanol butyl ether (1 mole, Nanjing Science and Technology Development Corporation of Forestry Institute), 189 g of tetraethylenepentamine (1 mole, Hangzhou Jiaxing Chemical Co., Ltd.) In a three-neck flask, add 30g of paraformaldehyde (1 mole, Nanjing Chemical Reagent Factory) in batches within 0.5 hours, control the reaction temperature between 80-90°C for 4 hours, then heat up to 100-120°C and steam under normal pressure. The water generated by the reaction was removed, and the final temperature was kept at 80-120° C. and distilled under reduced pressure until no water was evaporated, and 69 g of water was distilled out. Obtain 537g of light yellow oily cardanol butyl ether epoxy curing agent, the amine value is 481mg / g, and the yield is 96%.

technical field

[0001] The invention relates to a preparation method of an epoxy resin curing agent, in particular to a light-colored cardanol alkyl ether epoxy curing agent capable of curing-induced phase separation and a preparation method thereof. Background technique

[0002] Cardanol is a cashew nut shell cardanol is a natural biophenol with a 15-carbon long carbon chain in the meta-position of a monohydric phenol structure. Cardanol is non-toxic and non-corrosive, which is different from petroleum phenol, which is highly corrosive and highly toxic. It is more friendly to the environment and human body. Its structure is as follows:

[0003]

[0004] where n is 0, 1 or 2.

[0005] Cardanol has a wide range of uses and can be used in phenolic resins, epoxy resin curing agents, surfactants and demulsifiers. However, the phenolic hydroxyl group of cardanol is extremely easy to be oxidized by air into quinone derivatives, resulting in a very dark color of cardanol or d...

Examples

preparation example Construction

[0027] The preparation method of this light-colored cardanol alkyl ether epoxy curing agent is: 1 mole of cardanol alkyl ether and 1-3 moles of polyamines are mixed, then 1-3 moles of formaldehyde are added in batches, and the reaction temperature is controlled at React at 80-90°C for 4 hours, then heat up to 100-120°C to distill off the water generated by the reaction, and finally keep the temperature at 80-120°C and distill under reduced pressure until no water is evaporated, and then obtain cardanol alkyl ether through Mannich reaction epoxy curing agent.

[0028] In the preparation method of the above-mentioned light-colored cardanol epoxy curing agent, the structure of the cardanol alkyl ether used wherein is as follows:

[0029] where m is an integer from 0 to 22, and where n is 0, 1 or 2.

[0030] In the preparation method of the above-mentioned light-colored cardanol epoxy curing agent, wherein the polyamine used can be ethylenediamine, hexamethylenediamine, dihexyltr...

Embodiment 1

[0034] Mix 316g of cardanol methyl ether (1 mole, Nanjing Science and Technology Development Corporation of Institute of Forestry and Chemical Engineering) and 309g of diethylenetriamine (3 moles, Suzhou Xinxin Chemical Co., Ltd.) into a 2000 Add 243g of 37% formaldehyde solution (3 moles, Nanjing Chemical Reagent Factory) in batches within 0.5 hours, control the reaction temperature between 80-90°C for 4 hours, then raise the temperature to 100-120°C The water generated by the reaction was steamed under pressure, and the final temperature was kept at 80-120° C. under reduced pressure until no water was evaporated, and 207 g of water was evaporated. Obtain 641g of light yellow oily cardanol methyl ether epoxy curing agent, the amine value is 383mg / g, and the yield is 97%.

Embodiment 2

[0036] Mix 358 g of cardanol butyl ether (1 mole, Nanjing Science and Technology Development Corporation of Forestry Institute), 189 g of tetraethylenepentamine (1 mole, Hangzhou Jiaxing Chemical Co., Ltd.) In a three-neck flask, add 30g of paraformaldehyde (1 mole, Nanjing Chemical Reagent Factory) in batches within 0.5 hours, control the reaction temperature between 80-90°C for 4 hours, then heat up to 100-120°C and steam under normal pressure. The water generated by the reaction was removed, and the final temperature was kept at 80-120° C. and distilled under reduced pressure until no water was evaporated, and 69 g of water was distilled out. Obtain 537g of light yellow oily cardanol butyl ether epoxy curing agent, the amine value is 481mg / g, and the yield is 96%.

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