阅读说明：本技术 一种利用乙酰丙酸制备水基润滑油的方法 (Method for preparing water-based lubricating oil by utilizing levulinic acid ) 是由 张栩 杨雪 谭天伟 于 2019-10-17 设计创作，主要内容包括：本发明公开了一种利用乙酰丙酸制备水基润滑油的方法,先利用固体酸催化乙酰丙酸和多元醇进行直接酯化反应,合成出乙酰丙酸酯类水基润滑油粗产品。再对乙酰丙酸酯粗产品进行分子精馏,最终得到易溶于水、且能够与水形成稳定状态的润滑液。利用本方法生产的乙酰丙酸酯类水基润滑剂,以羟基含量丰富的丙三醇及分子链较长的低聚丙三醇与乙酰丙酸为原料酯化生成的水基润滑油支链数较多且极性较大导致其摩擦附着力较大、氧化稳定性与热力学稳定性增加,同时水溶性良好。以较小的比例与水混合后仍能形成十分稳定且摩擦系数较小的润滑油,大大减少了工业操作中二聚丙三醇乙酰丙酸酯的使用量,从而节省成本,易于清洗,对环境污染小。(The invention discloses a method for preparing water-based lubricating oil by utilizing levulinic acid. And performing molecular rectification on the crude levulinate product to finally obtain the lubricating liquid which is easily soluble in water and can form a stable state with the water. The levulinic acid ester water-based lubricant produced by the method takes glycerol with rich hydroxyl content and oligomeric glycerol with longer molecular chains and levulinic acid as raw materials, and the water-based lubricant produced by esterification has more branched chains and larger polarity, thus leading the friction adhesion to be larger, the oxidation stability and the thermodynamic stability to be increased, and simultaneously having good water solubility. The lubricant oil can still form stable lubricant oil with small friction coefficient after being mixed with water in a small proportion, and greatly reduces the use amount of the dimeric glycerol levulinate in industrial operation, thereby saving the cost, being easy to clean and having little pollution to the environment.)

1. A method for preparing water-based lubricating oil by utilizing levulinic acid is characterized by comprising the following steps: firstly, catalyzing levulinic acid and polyhydric alcohol by using solid acid to perform direct esterification reaction to synthesize a crude levulinic acid ester water-based lubricating oil product; then molecular rectification is carried out on the crude product of the levulinic acid ester, and finally the lubricating liquid which is easy to dissolve in water and can form a stable state with the water is obtained; after the reaction is finished, the solid acid and the product are convenient to separate and can be recycled for multiple times;

the method takes levulinic acid and polyhydric alcohol as raw materials and comprises the following steps:

a) esterification: levulinic acid and polyhydric alcohol are used as raw materials, the molar ratio of the levulinic acid to the polyhydric alcohol is (4-5):1, the dosage of Amberlyst15 ion exchange resin is 2 percent of the total mass of the substrate, the reaction temperature is 95-120 ℃, and the reaction time is 4-12 h; the polyol is glycerol or diglycerol; under the catalysis of acid, levulinic acid is directly esterified with diglycerol and glycerol respectively; removing generated water in the esterification reaction in a vacuum environment to finally obtain a crude product of the levulinic acid ester water-based lubricating oil;

b) refining treatment: filtering the crude product of the levulinic acid polyol ester to remove the solid acid catalyst Amberlyst15, removing the levulinic acid and water from the obtained liquid by adopting molecular rectification equipment under the conditions of 1mbar, 130-145 ℃, and then rectifying again at 225-260 ℃ to obtain a levulinic acid ester water-based lubricating oil product with higher purity;

finally forming a low-viscosity water-containing nano anti-friction film under the synergistic action of the levulinate and water, thereby reducing the friction between the two friction pairs; at normal temperature, the nanometer anti-friction film is very stable in an environment containing hydrogen bonds.

2. The method for producing water-based lubricating oil by esterification according to claim 1, wherein: the levulinic acid used is derived from renewable agricultural and forestry waste or non-grain biomass of energy crops.

3. The method for producing a levulinic acid ester-based water-based lubricating oil according to claim 1, wherein: the catalyst Amberlyst15 is solid acid catalyst, and is easy to separate from glycerin levulinate and dimeric glycerin levulinate.

Technical Field

The invention relates to a preparation method and application of water-based lubricating oil, in particular to ester metal processing working solution in a synthetic lubricating oil preparation.

Background

The lubricating oil is a lubricating medium for reducing the frictional resistance of the pair and slowing down the abrasion of the pair. Lubricating base oils are classified into five major groups in total according to the classification of API (Mobil Petroleum institute), of which ester-based synthetic lubricating oils belong to group V. In order to improve the efficiency of the metal material processing technology, improve the product quality, reduce the frictional resistance, reduce the tool abrasion and the like, a proper lubricant should be selected. Synthetic oils, known as biolubricants, have received extensive attention and research due to their good lubricity, biodegradability, viscosity-temperature characteristics, and low volatility.

Natural animal and vegetable oils have good lubricating properties and load-bearing capacity, but are poor in oxidation resistance and sensitive to temperature changes, and therefore are not suitable for use as lubricating base oils. Mineral oil is processed by petroleum and is most widely applied at present, but because the mineral oil cannot remove impurities completely in the refining process, the obtained base oil has high pour point and is not suitable for being used in cold environments. At the same time, mineral oils have also gradually failed to meet the requirements of the rapidly developing mechanical industry. The use of polyol ester lubricating oils as base oils has many excellent properties: good oxidation stability, high viscosity index, good working performance under low temperature, high thermal stability, good abrasion resistance and the like. Particularly, the lubricant used in the processes of turning, milling, partial medical apparatus and part of medical apparatus, drawing, punching, bending and the like of a male die in the forming process of a metal workpiece requires not only good lubricating performance but also good cooling performance, so that the requirements cannot be met by using the traditional lubricating oil, and the water-based lubricant exerts unique advantages and is widely applied. Water-based lubricants, which are generally emulsified from oily substances such as animal and vegetable fats and oils, mineral oils, and synthetic ester oils, have excellent lubricity, cooling properties, cleaning properties, and safety, and are used in large quantities in metal working fluids such as cutting fluids and drawing fluids. Besides, the water-based lubricating oil also has the advantages of good permeability, small environmental pollution, prolonged service life of the die, power and energy conservation, easy cleaning and the like.

Meanwhile, the molecular chain of the polymeric polyol is longer, the polymeric polyol can be dispersed in an aqueous solution to form a film similar to a brush structure, and the friction between two friction pairs can be remarkably reduced due to the formation of the water-like film, so that the water-based lubricating oil prepared by using the polymeric polyol can show good anti-friction performance.

Disclosure of Invention

The invention aims to prepare the water-based lubricating oil which can be easily dissolved in water to form a stable state and is safe and environment-friendly. The levulinic acid is derived from lignocellulose with rich and completely renewable content, and the acetyl functional group contained in the levulinic acid endows the levulinic acid with good water solubility, so that the ester water-based lubricating oil with good performance prepared by utilizing the levulinic acid has great potential. The glycerol can be mutually soluble with water in any proportion, and the water solution is neutral; polyglycerol is low in volatility and hygroscopicity, and has the characteristic of improving the emulsion stability. The levulinic acid, the glycerol and the polyglycerol can be used for producing and preparing the water-based ester lubricating oil which is easy to dissolve in water and has no toxicity.

The technical problems of the invention are mainly solved by the following technical scheme: a method for preparing water-base lubricating oil by utilizing levulinic acid is characterized in that firstly, the levulinic acid and polyhydric alcohol are catalyzed by solid acid to carry out direct esterification reaction, and a crude product of the levulinic acid ester water-base lubricating oil is synthesized. And performing molecular rectification on the crude levulinate product to finally obtain the lubricating liquid which is easily soluble in water and can form a stable state with the water. The whole process is simple to operate, mild in condition, excellent in product performance and environment-friendly. Meanwhile, after the reaction is finished, the solid acid and the product are convenient to separate and can be recycled for multiple times.

A method for preparing water-based lubricating oil by utilizing levulinic acid, which takes the levulinic acid and polyhydric alcohol as raw materials, is characterized by comprising the following steps:

a) esterification: levulinic acid and polyhydric alcohol are used as raw materials, the molar ratio of the levulinic acid to the polyhydric alcohol is (4-5):1, the dosage of Amberlyst15 ion exchange resin is 2 percent of the total mass of the substrate, the reaction temperature is 95-120 ℃, and the reaction time is 4-12 h. Under the catalytic condition of acid, levulinic acid is directly esterified with diglycerol and glycerol respectively, and the reaction path is shown in figure 1 and figure 2. And (3) removing generated water in the esterification reaction under a vacuum environment to finally obtain the crude product of the levulinic acid ester water-based lubricating oil.

b) Refining treatment: filtering the crude product of the levulinic acid polyol ester to remove the solid acid catalyst Amberlyst15, removing the levulinic acid and water from the obtained liquid by adopting molecular rectification equipment under the conditions of 1mbar, 130-145 ℃, and then rectifying again at 225-260 ℃ to obtain the levulinic acid ester water-based lubricating oil product with higher purity.

The levulinic acid used is derived from renewable non-grain biomass such as agricultural and forestry waste, energy crops and the like, such as straws, bagasse, switchgrass and the like, and the raw material source is very wide.

The polyol is glycerol or diglycerol, and has wide sources, rich content and low price.

The catalyst Amberlyst15 is solid acid catalyst, and is easy to separate from glycerin levulinate and dimeric glycerin levulinate.

The possible anti-friction principle mechanism of the water-based lubricating oil is as follows: the low-viscosity water-containing nano anti-friction film is finally formed under the synergistic action of the levulinate and water, so that the friction between two friction pairs is reduced. At normal temperature, the nanometer anti-friction film is very stable in an environment containing hydrogen bonds.

The levulinic acid ester water-based lubricant produced by the method takes glycerol with rich hydroxyl content and oligomeric glycerol with longer molecular chains and levulinic acid as raw materials, and the water-based lubricating oil generated by esterification has more branched chains and larger polarity, so that the friction adhesion is larger, the oxidation stability and the thermodynamic stability are improved, and the water solubility is good, thereby having very ideal water-based lubricating oil performance. Especially, because the dimer glycerin levulinate has longer molecular chain, the dimer glycerin levulinate is dispersed in the water solution to form a film similar to a 'brush' structure, the friction between two friction pairs can be obviously reduced by the formation of the water-like film, and lubricating oil which is very stable and has smaller friction coefficient can be formed after being mixed with water in a smaller proportion, so that the usage amount of the dimer glycerin levulinate in industrial operation can be greatly reduced, the cost is saved, the dimer glycerin levulinate is easy to clean, and the environmental pollution is small.

Drawings

FIG. 1 shows the reaction route for esterification of levulinic acid with glycerol.

FIG. 2 shows the reaction route for esterification of levulinic acid with dimerlotriptan.

FIG. 3 is a graph of the coefficient of friction for homogeneous solutions of different water contents of diglycerol levulinic acid ester.

Detailed Description