阅读说明：本技术 生物基环氧树脂乳化剂及其水性乳液与制备方法 (Bio-based epoxy resin emulsifier, water-based emulsion thereof and preparation method ) 是由 周继亮 张俊珩 张道洪 李廷成 于 2020-04-21 设计创作，主要内容包括：本发明公开了一种生物基环氧树脂乳化剂。该乳化剂结构中既有疏水性的没食子酸基环氧树脂分子链段,又有亲水性的柔性聚醚醇胺多嵌链段,还有含磷的DOPO分子链段；因此能够在水性条件下较好地乳化没食子酸基环氧树脂。本发明还公开了该乳化剂乳化没食子酸基环氧树脂所得到的水性乳液及其制备方法。制备得到的水性乳液稳定、粒径细小,且具有阻燃功能。(The invention discloses a bio-based epoxy resin emulsifier. The emulsifier has the structure that the emulsifier has a hydrophobic gallic acid group epoxy resin molecular chain segment, a hydrophilic flexible polyether alcohol amine multi-block chain segment and a phosphorus-containing DOPO molecular chain segment; therefore, the gallic acid-based epoxy resin can be preferably emulsified under aqueous conditions. The invention also discloses an aqueous emulsion obtained by emulsifying gallic acid group epoxy resin by the emulsifier and a preparation method thereof. The prepared water-based emulsion is stable, has fine particle size and has a flame retardant function.)

1. A preparation method of a bio-based epoxy resin emulsifier is characterized by comprising the following steps: the method comprises the following steps:

1) preparation of GAE-nDOPO adduct solution:

adding gallic acid base epoxy resin, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and a solvent into a reaction device provided with a stirring device and a condensing device, adding triphenylphosphine serving as a catalyst after reactants are completely and uniformly dispersed, heating to 120-160 ℃, and stirring and reacting for 4-10 hours in an inert atmosphere to completely react to obtain a GAE-nDOPO adduct solution; the size of n is as follows: n is more than or equal to 1 and less than or equal to 3;

2) synthesis of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA):

firstly, dripping polyether alcohol diglycidyl ether into an organic solvent containing ethanolamine at 40-80 ℃ to carry out chain extension reaction to obtain an intermediate product MEA-PEGGE-MEA solution; the material molar ratio of the ethanolamine to the polyether alcohol diglycidyl ether is 3-4: 1; dropwise adding the GAE-nDOPO adduct solution into the MEA-PEGGE-MEA solution at 50-80 ℃ for addition reaction to obtain a GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) adduct solution; the ratio of the amount of GAE-nDOPO in the GAE-nDOPO adduct solution to the amount of MEA-PEGGE-MEA in the MEA-PEGGE-MEA solution is 1: (4-n);

3) synthesis of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE):

dropwise adding the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) adduct solution into an organic solvent containing polyether alcohol diglycidyl ether at the temperature of 40-90 ℃, wherein the ratio of the amount of substances of the polyether alcohol diglycidyl ether in the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) and the organic solvent containing the polyether alcohol diglycidyl ether is 1: (4-n), performing addition reaction on the ammonia hydrogen on the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) adduct and an epoxy group at one end of polyether alcohol diglycidyl ether to synthesize a GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE) adduct solution, and adjusting the hydrophilic-lipophilic balance value of the solution to be 13.0-16.8; then distilling under reduced pressure to remove the solvent, thus preparing the bio-based epoxy resin emulsifier.

2. The method for preparing bio-based epoxy resin emulsifier according to claim 1, wherein: in the step 1), the mass ratio of 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to epoxy group on the gallic acid group epoxy resin is n: 4.

3. the method for preparing bio-based epoxy resin emulsifier according to claim 1 or 2, wherein: in the step 1), the mass of the triphenylphosphine is 7-9% of the sum of the mass of 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and the mass of the gallic acid base epoxy resin.

4. The method for preparing bio-based epoxy resin emulsifier according to claim 1 or 2, wherein: in the step 2), the polyether alcohol diglycidyl ether is polyethylene glycol diglycidyl ether.

5. The method for preparing bio-based epoxy resin emulsifier according to claim 1 or 2, wherein: in the step 2), the organic solvent is propylene glycol methyl ether.

6. The method for preparing bio-based epoxy resin emulsifier according to claim 1 or 2, wherein: in the step 3), the specific method for adjusting the hydrophilic-lipophilic balance value comprises the following steps: after synthesizing an additive solution of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE), dropwise adding a proper amount of glacial acetic acid aqueous solution and amino groups on the additive solution of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE) at the temperature of 40-60 ℃ for neutralization and salt formation.

7. A bio-based epoxy resin emulsifier obtained by the production method according to any one of claims 1 to 6.

8. The method of claim 7 wherein the bio-based epoxy resin emulsifier emulsifies gallic acid based epoxy resin to form an aqueous emulsion, the method comprising: the method comprises the following steps: carrying out reduced pressure distillation on the GAE-nDOPO addition product solution prepared according to the step 1) to obtain a GAE-nDOPO addition product, wherein the weight ratio of the GAE-nDOPO addition product solution to the GAE-nDOPO addition product solution is 1: 3-3: taking 100 parts by weight of gallic acid base epoxy resin and GAE-nDOPO addition product as emulsified substances according to a proportion, adding 15-20 parts by weight of the bio-based epoxy resin emulsifier, putting into a container with a stirring device, uniformly mixing, and heating to 85-90 ℃; under the condition of stirring materials at 900-950 rpm, 100 parts by weight of deionized water is dripped into the stirred materials, after the water is dripped, the materials are stirred for 50-60 min, and then the temperature is reduced and the materials are discharged to obtain the aqueous emulsion with the solid content of 53-55%.

9. An aqueous emulsion prepared by the process of claim 8.

Technical Field

The invention relates to the technical field of epoxy resin, in particular to a bio-based epoxy resin emulsifier, a water-based emulsion thereof and a preparation method thereof.

Background

The epoxy resin material has the advantages of excellent bonding performance, electric insulation performance, low shrinkage rate, high strength and modulus and the like, and plays an important role in the fields of electronics, ships, aerospace, mechanical manufacturing and the like. Conventional petroleum-based derivative type epoxy resins such as bisphenol a type epoxy resins, which require bisphenol a as a raw material for the preparation of petroleum derivatives, require the consumption of a large amount of non-renewable petroleum resources; and bisphenol a is considered a chemical potentially harmful to human health. Due to the increasing shortage of petroleum resources and the increasing awareness of sustainable development, the gradual replacement of petroleum-based derivatives by green bio-based raw materials and derivatives has become an irreversible development trend for the synthesis and preparation of bio-based epoxy resins. In recent years, there is a report in the literature that a gallic acid-based epoxy resin having excellent properties can be prepared by reacting a bio-based gallic acid with epichlorohydrin. In addition, the traditional solvent-based epoxy resin brings harm to ecological environment due to containing a large amount of organic solvent, and is increasingly difficult to meet the requirement of the market on green environmental protection. The waterborne epoxy resin takes water as a dispersion medium instead of an organic solvent, and has the advantages of environmental protection. However, most of the aqueous epoxy resins reported in the prior art are still based on conventional petroleum-based derivative type epoxy resins, such as water-soluble bisphenol A type epoxy resin emulsions or aqueous phenol-formaldehyde epoxy resin emulsions.

Disclosure of Invention

The invention aims to provide a bio-based epoxy resin emulsifier which can well emulsify gallic acid group epoxy resin (GAE) under the aqueous condition.

In order to solve the technical problems, the biological epoxy resin emulsifier provided by the invention is prepared by adopting the following technical scheme:

(1) preparation of GAE-nDOPO adduct solution

The gallic acid base epoxy resin (GAE) is prepared by the prior technical scheme. For example, the following technical solutions may be adopted: taking bio-based Gallic Acid (GA) and Epoxy Chloropropane (ECH) as raw materials, heating to 100-110 ℃, and carrying out ring-opening reaction under the action of a catalyst (such as tetrabutylammonium bromide) for 4-8 hours; and then adding NaOH solution into the reaction solution at room temperature to carry out ring-closure reaction for 2-4 hours, adding water to wash the reaction solution to be neutral, standing the reaction solution for layering, and distilling the oil layer under reduced pressure to obtain the light yellow semisolid gallic acid base epoxy resin.

Adding GAE, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and a solvent into a reaction device provided with a stirring device, a condensing device and an inert atmosphere (introduced with nitrogen or inert gas), adding triphenylphosphine serving as a catalyst after reactants GAE and DOPO are completely and uniformly dispersed, heating to 120-160 ℃, and stirring for reacting for 4-10 hours to completely react to obtain a GAE-nDOPO adduct solution; the size of n is as follows: n is more than or equal to 1 and less than or equal to 3. The reaction equation can be shown as follows:

(2) synthesis of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA)

Firstly, adding polyether alcohol diglycidyl ether (PEGGE) dropwise into an organic solvent containing ethanolamine (MEA) at 40-80 ℃ to perform chain extension reaction (the molar ratio of the MEA to the added PEGGE is 3-4: 1), removing redundant MEA after the reaction is finished by reduced pressure distillation to obtain an intermediate product MEA-PEGGE-MEA, and dissolving and dispersing the intermediate product MEA-PEGGE-MEA by using the organic solvent to obtain an MEA-PEGGE-MEA solution; and dropwise adding the GAE-nDOPO adduct solution into the MEA-PEGGE-MEA solution at 50-80 ℃ for addition reaction to obtain the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) adduct solution. The ratio of the amount of GAE-nDOPO in the GAE-nDOPO adduct solution to the amount of MEA-PEGGE-MEA in the MEA-PEGGE-MEA solution is 1: (4-n). The reaction equation can be shown as follows:

(3) synthesis of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE)

Dropwise adding the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) adduct solution into an organic solvent containing PEGGE at the temperature of 40-90 ℃, wherein the ratio of the amount of substances of the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) to the amount of the PEGGE in the organic solvent containing PEGGE is 1: (4-n). The method comprises the steps of carrying out addition reaction on ammonia hydrogen on a GAE-nDOPO- (4-n) (MEA-PEGGE-MEA) addition product solution and an epoxy group at one end of a PEGGE (the epoxy group at the other end is reserved for participating in curing reaction when in application), synthesizing the GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE) addition product solution, adjusting the hydrophile-lipophile balance value to be 13.0-16.8 (as known by technical personnel in the field, if the hydrophile-lipophile balance value of the GAE-nDOPO- (4-n) (MEA-PEGGE-addition product solution is 13.0-16.8, no adjustment is needed or no adjustment method is needed), and then carrying out reduced. The reaction equation can be shown as follows:

further, in the step (1), the ratio of the DOPO to the epoxy group on the GAE is n: 4.

further, in the step (1), the mass of the triphenylphosphine is 7-9% of the sum of the masses of DOPO and GAE.

Further, in the step (2), the polyether alcohol diglycidyl ether is polyethylene glycol diglycidyl ether.

Further, in the step (2), the organic solvent is propylene glycol methyl ether.

Further, in the step (3), the specific method for adjusting the hydrophilic-lipophilic balance value thereof comprises: after synthesizing an additive solution of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE), dropwise adding a proper amount of glacial acetic acid aqueous solution and amino on the additive solution of GAE-nDOPO- (4-n) (MEA-PEGGE-MEA-PEGGE) at the temperature of 40-60 ℃ for neutralization and salt formation.

The invention also provides a water-based emulsion obtained by emulsifying gallic acid group epoxy resin with the biological epoxy resin emulsifier. The preparation method comprises the following specific steps: according to the weight ratio of 1: 3-3: taking 100 parts by weight of gallic acid base epoxy resin (GAE) and the product obtained by carrying out reduced pressure distillation on the GAE-nDOPO adduct solution prepared in the step (1) as an emulsified substance according to a proportion, adding 15-20 parts by weight of bio-based epoxy resin emulsifier, putting into a container with a stirring device, uniformly mixing, and heating to 85-90 ℃; under the condition of stirring materials at 900-950 rpm, 100 parts by weight of deionized water is dripped into the stirred materials, after the water is dripped, the materials are stirred for 50-60 min, and then the temperature is reduced and the materials are discharged to obtain the aqueous emulsion with the solid content of 53-55%.

The invention is based on that the gallic acid base epoxy resin is a hydrophobic substance, can not be directly dissolved and dispersed in water, is a semisolid substance with high viscosity at room temperature, and is difficult to be emulsified into a stable emulsion by a common emulsifier. Therefore, the key to the preparation of the gallic acid group epoxy resin water-based emulsion is to synthesize the gallic acid group epoxy resin emulsifier with a special structure. In order to increase the similarity of the emulsifier and an emulsified substance, hydrophobic gallic acid-based epoxy resin molecular chain segments are introduced into the structure of the emulsifier; in order to enhance the water solubility, hydrophilic flexible polyether alcohol amine multi-block segments are introduced; in order to avoid forming a cross-linking structure between the hydrophobic gallic acid group epoxy resin molecular chain segment and the hydrophilic flexible polyether alcohol amine multi-block chain segment, the invention also introduces a phosphorus-containing DOPO molecular chain segment between the hydrophobic gallic acid group epoxy resin molecular chain segment and the hydrophilic flexible polyether alcohol amine multi-block chain segment. The emulsifier prepared in the way has a unique molecular structure, is beneficial to improving the emulsifying performance of the emulsifier on the gallic acid group epoxy resin and the derivatives thereof, can prepare stable water-based gallic acid group epoxy resin emulsion with small particle size, is green and environment-friendly, and more accords with the sustainable development concept.

Compared with the prior art, the method has the advantages and beneficial effects as follows:

emulsifying the bio-based gallic acid base epoxy resin under the action of a self-made emulsifier with a special structure to prepare stable waterborne gallic acid base phosphorus-containing epoxy resin emulsion with small particle size, which is relative to common waterborne petroleum base derivative epoxy resin, such as waterborne bisphenol A epoxy resin emulsion; has the function of flame retardation, takes the bio-based as the raw material, is more green and environment-friendly, and is more beneficial to sustainable development.

Drawings

FIG. 1 is an IR spectrum of GAE-2DOPO-2 (MEA-PEGGE-MEA-PEGGE).

FIG. 2 is a graph showing the particle size distribution of the emulsion prepared in example 1.

FIG. 3 is a particle size distribution of the emulsion prepared in example 2.

FIG. 4 is a particle size distribution of the emulsion prepared in example 3.

FIG. 5 shows the particle size distribution of a water-soluble bisphenol A epoxy resin emulsion.

FIG. 6 shows the particle size distribution of the aqueous novolac epoxy resin emulsion.

Detailed Description

For a better understanding of the present invention, reference is made to the following detailed description taken in conjunction with the accompanying drawings and specific examples, but the scope of the invention as claimed is not limited to the examples shown.