Method for synthesizing alkyd resin by utilizing lac eleostearic acid

Abstract

The invention discloses a method for synthesizing alkyd resin by utilizing lac eleostearic acid, which comprises the following steps: mixing lac eleostearic acid, polyol and fatty acid according to a molar ratio of 1: (1.2-3): (0.6-1.2), and putting into a reaction kettle; under the stirring condition, gradually heating to 160-230 DEG C, maintaining the reaction temperature, carrying out esterification reaction, and promoting the reaction by continuously dehydrating and controlling the water removal speed in the esterification reaction process; stopping heating after the reaction is finished, and cooling to room temperature to obtain an alkyd resin product. The alkyd resin synthesized by the method has better biodegradability, has less influence on the environment, and is beneficial to reduction of plastic garbage and chemical pollution; the synthesis process is optimized, the energy utilization efficiency can be improved, the energy consumption in the production process is reduced, and meanwhile, the environmental pollution is reduced; the alkyd resin synthesized by the invention has better mechanical property, chemical resistance and weather resistance, and can be used in various application fields.

Description

Technical Field

[0001] The invention belongs to the technical field of material synthesis, and particularly relates to a method for synthesizing alkyd resin by utilizing elaiophyllic acid. Background Art

[0002] Alkyd resin is an important polymer material, widely used in coatings, paints, adhesives and other fields. It has attracted much attention due to its excellent weather resistance, adhesion, gloss and hardness. However, the synthesis of traditional alkyd resin usually relies on petroleum-based chemicals as raw materials, facing the problems of resource depletion and environmental pollution. With the improvement of environmental awareness, the use of natural resources as raw materials for the synthesis of alkyd resin has become a research hotspot.

[0003] Although the existing alkyd resin synthesis method has excellent performance, it is insufficient in environmental protection, cost control and sustainable development. Therefore, how to use natural resources to develop a green, environmentally friendly and economical alkyd resin synthesis method has become a technical bottleneck in the field. In the disclosed patents on synthetic alkyd resin, invention patent CN104262595A discloses a process for synthesizing water-based alkyd resin, by selecting a four-mouth flask as a reactor, adding soybean oil acid, benzoic acid, pentaerythritol, phthalic anhydride, 2,2-dimethylol propionic acid and reflux xylene inside, passing carbon dioxide gas to replace the internal air, heating up and then constant temperature esterification reaction, after vacuuming, the internal reflux xylene is removed, the maleic anhydride oil added, heat preservation reaction, passing triethylamine for neutralization reaction, adding deionized water, stirring, and obtaining a finished water-based alkyd resin. However, water-based alkyd resin may produce some wastewater and waste materials in the production process, causing environmental pollution, and it is inferior to traditional solvent-based alkyd resin in terms of hardness, gloss, adhesion, etc. CN102504222A discloses a method for synthesizing an alkyd resin. The method first uses 30-33wt% fatty acid, 22-25wt% polyol, and 25-30wt% crude terephthalic acid, melts at high temperature for condensation reaction, and after the system is transparent, 4-10wt% phthalic anhydride, 4-8wt% benzoic acid and 0.2-1.0wt% maleic anhydride, 3-5wt% polyol and 4wt% reflux xylene are added after cooling, and the temperature is raised and kept in stage, and further esterification reaction is carried out by solvent method until the acid value and viscosity of the system are qualified; finally, the temperature is lowered and the mixture is put into a dilution kettle and diluted with 28-35wt% solvent, and the product can be filtered after stirring evenly. However, in the production process, not only are the reaction conditions relatively strict, but also the organic solvents such as xylene used may cause pollution to the environment and pose potential risks to the health of operators. For this reason, it is very necessary to develop a method for synthesizing an alkyd resin that uses natural, easily accessible renewable resources as production raw materials, has little environmental pollution, and has excellent alkyd resin performance. Summary of the invention

[0004] In order to solve the technical problems of excessive reliance on petroleum-based raw materials and serious environmental pollution in the process of synthesizing alkyd resin in the prior art, the present invention aims to provide a method for synthesizing alkyd resin using elaiophyllic acid, aiming to optimize the process, reduce environmental pollution, and synthesize alkyd resin with excellent performance.

[0005] The object of the present invention is achieved by comprising the following steps: S1. Mix elaeis acid, polyol and fatty acid in a molar ratio of 1:1.2-3:0.6-1.2 and put into a reaction kettle; S2. Under stirring conditions, gradually heat to 160°C~230°C and maintain the reaction temperature to carry out esterification reaction. During the esterification reaction, the water removal rate is controlled by continuous dehydration to promote the reaction; S3. After the reaction is completed, stop heating and cool to room temperature to obtain an alkyd resin product.

[0006] After the reaction is completed, unreacted raw materials and by-products can be removed by filtering, centrifuging or settling to improve the purity of the alkyd resin; the alkyd resin synthesized by the present invention can be diluted by a solvent or heated to adjust its viscosity and application performance; the alkyd resin synthesized by the present invention can also be modified by adding an appropriate amount of pigment, filler or additive to meet the needs of specific applications; the alkyd resin synthesized by the present invention can be tested and analyzed for performance by instruments such as a rheometer, DSC (differential scanning calorimetry) or FTIR (Fourier transform infrared spectroscopy).

[0007] Preferably, the polyol is one or more of glycerol, pentaerythritol, sorbitol, ethylene glycol, and trimethylolpropane.

[0008] Preferably, the fatty acid is one or more of plant oleic acid and animal oleic acid, and the fatty acid is plant oleic acid or animal oleic acid of natural origin, so as to improve the biodegradability and environmental friendliness of the resin.

[0009] Preferably, the esterification reaction time is 4 h to 8 h, and the reaction in step S3 is completed when the acid value of the reaction drops below 8 mg KOH / g to 40 mg KOH / g.

[0010] Preferably, the pH of the esterification reaction is controlled at 5-7 to ensure the stability of the reaction and the quality of the product.

[0011] Preferably, the esterification reaction pressure is controlled at 0.1 MPa to 1.0 MPa to promote the esterification reaction and increase the molecular weight of the product.

[0012] Preferably, an antioxidant, preservative or plasticizer is added to the alkyd resin product obtained in step S3, specifically butylated p-cresol, butylated hydroxyanisole, bromophenol, sodium benzoate, dioctyl phthalate, epoxy soybean oil, etc.

[0013] Principle of the present invention: Alkyd resins are synthesized by esterification of polyols with acids containing multiple carboxyl groups (elaeuric acid) and fatty acids; esterification is an organic chemical reaction in which the hydroxyl group (-OH) of an alcohol reacts with the carboxyl group (-COOH) of a carboxylic acid to form an ester and a water molecule. In the present invention, elaeis acid is a natural organic acid having multiple carboxyl groups and can undergo esterification reaction with polyols and fatty acids; Each hydroxyl group of the polyol can react with the carboxyl group of the carboxylic acid to form an ester bond; the fatty acid also participates in the esterification reaction and reacts with the hydroxyl group of the polyol to form an ester bond; this increases the molecular weight and complexity of the alkyd resin; in the reactor, elaeis acid, polyols and fatty acids react under heating and stirring conditions; during the reaction, the generated water molecules are excluded to drive the reaction in the direction of the product; the synthesized alkyd resin can be used in coatings, inks, adhesives or plastics to replace traditional petroleum-based alkyd resins and achieve sustainable development.

[0014] Beneficial effects of the present invention: 1. Aleuritic acid is a natural organic acid and a renewable resource. Using it as one of the main raw materials can reduce the dependence on petroleum-based raw materials, so that the present invention effectively reduces environmental pollution. The use of aleuritic acid and other raw materials from natural sources (such as vegetable oleic acid or animal oleic acid) can reduce the cost of raw materials because these raw materials are usually more economical than petroleum-based raw materials. 2. The alkyd resin synthesized by the present invention has better biodegradability, less impact on the environment, and helps to reduce plastic waste and chemical pollution; the present invention optimizes the synthesis process, can improve energy utilization efficiency, and reduce energy consumption in the production process; 3. The present invention optimizes the synthesis process, is simple and easy to operate, and can synthesize an alkyd resin with excellent properties. The alkyd resin synthesized by the present invention has better mechanical properties, chemical resistance and weather resistance, and can be used in a variety of application fields, such as coatings, inks, adhesives and plastics; 4. The present invention uses natural and renewable raw materials and optimizes the synthesis process, which not only improves the performance and application range of alkyd resin, but also helps to reduce environmental pollution, which is in line with the trend of sustainable development. DETAILED DESCRIPTION

[0015] The present invention is further described below in conjunction with the embodiments, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0016] Example 1 The method for synthesizing alkyd resin using elaiolate in this embodiment comprises the following steps: S1. Mix elaeis acid, polyol and fatty acid in a molar ratio of 1:1.5:1 and put into a reaction kettle; wherein the polyol is glycerol and the fatty acid is vegetable oleic acid; S2. Under stirring conditions, gradually heating to 180° C. and maintaining the reaction temperature to carry out esterification reaction, controlling the pH at 6 and the pressure at 0.5 MPa. During the esterification reaction, the water removal rate is controlled by continuous dehydration to promote the reaction; S3, when the acid value of the reaction drops below 10mg KOH / g, stop heating and cool to room temperature to obtain an alkyd resin product; The product can be used in the coating industry. Performance testing shows that the viscosity of the alkyd resin solution is 800 mPa·s (milliPascal seconds), the solid content is 60%, and the coating film has a surface drying time of 30 minutes and a practical drying time of 24 hours under the conditions of 25°C and a relative humidity of 50%. After being immersed in a 10% sulfuric acid solution for 24 hours, the mass loss rate is 0.5%, the appearance has no obvious change, and the cross-hatch test result is level 4, showing good adhesion. This shows that the alkyd resin synthesized by the invention has an ideal effect.

[0017] Example 2 The method for synthesizing alkyd resin using elaiolic acid in this embodiment is based on the embodiment 1, and the difference from the embodiment 1 is that: in step S1, the elaiolic acid, the polyol and the fatty acid are in a molar ratio of 1:2:0.8, the polyol is pentaerythritol, and the fatty acid is animal oleic acid; in step S2, the temperature is heated to 200°C, the pH is controlled at 6.5, and the pressure is controlled at 0.7Mpa; in step S3, the acid value is reduced to below 15mgKOH / g; the product is used for ink manufacturing; According to the performance test, the color value of the cured alkyd resin is Lab* = (50, 2, -3), and the glossiness at an angle of 60° is 80 GU; after the test of the rotary rubber abrasion tester, the mass loss rate is 0.02g, showing excellent wear resistance. The hardness value measured by the pendulum hardness tester is 4H, showing a high hardness; after immersion in water for 24 hours, the water absorption rate is 0.1%, and the appearance does not change; indicating that the alkyd resin synthesized by the present invention has an ideal effect.

[0018] Example 3 The method for synthesizing alkyd resin using elaiolic acid in this embodiment is based on the embodiment 1, and the difference from the embodiment 1 is that: in step S1, elaiolic acid, polyol and fatty acid are in a molar ratio of 1:1.2:0.6, the polyol is sorbitol, and the fatty acid is vegetable oleic acid; in step S2, the temperature is heated to 220°C, the pH is controlled at 5.5, and the pressure is controlled at 0.3Mpa; in step S3, the acid value is reduced to below 20mgKOH / g; the product is used for adhesive; According to performance testing, the alkyd resin has a tensile strength of 8 MPa and a shear strength of 10 MPa. It maintains stable bonding performance at 80°C without falling off or melting. After 500 hours of artificial accelerated aging test, there is no obvious cracking or powdering, and the elongation at break is 120%, showing good flexibility. After the impact test, the sample bonded by the adhesive has no cracks and strong impact resistance, indicating that the alkyd resin synthesized by the present invention has an ideal effect.

[0019] Example 4 The method for synthesizing alkyd resin using elaiodic acid in this embodiment is based on the embodiment 1, and the difference from the embodiment 1 is as follows: in step S1, the elaiodic acid, the polyol and the fatty acid are in a molar ratio of 1:3:1.2, the polyol is ethylene glycol, and the fatty acid is animal oleic acid; in step S2, the temperature is heated to 190°C, the pH is controlled at 6, and the pressure is controlled at 0.4Mpa; in step S3, the acid value is reduced to below 8mg KOH / g; and the product is used in the plastics industry; According to performance tests, the alkyd resin has a tensile strength of 40 MPa, an elongation at break of 5%, a hardness of 80 Shore A, a TGA test showing a 5% thermal weight loss temperature of 280°C, a DSC test showing a glass transition temperature of 50°C, a melt index of 15 g / 10 min, a fluidity grade of 3, and a color change △E*ab of less than 3 after 1000 hours of artificial accelerated aging test, which is maintained well, a resistivity of 1×10^15 Ω·cm, and a dielectric constant of 3.5, indicating that the alkyd resin synthesized by the present invention has an ideal effect.

[0020] Example 5 The method for synthesizing alkyd resin using elaiolic acid in this embodiment is based on Example 1, and the difference from Example 1 is that: in step S1, elaiolic acid, polyol and fatty acid are in a molar ratio of 1:1.2:0.6, the polyol is trimethylolpropane, and the fatty acid is animal oleic acid; in step S2, the temperature is heated to 160° C., the pH is controlled at 5, and the pressure is controlled at 0.1 MPa; in step S3, the acid value is reduced to below 8 mg KOH / g.

[0021] Example 6 The method for synthesizing alkyd resin using elaiolic acid in this embodiment is based on Example 1, and the difference from Example 1 is that: in step S1, elaiolic acid, polyol and fatty acid are mixed in a molar ratio of 1:3:1.2, the polyol is glycerol and pentaerythritol in a mass ratio of 1:1, and the fatty acid is vegetable oleic acid and animal oleic acid in a mass ratio of 1:1; in step S2, the temperature is heated to 230° C., the pH is controlled at 7, and the pressure is controlled at 1.0 MPa; in step S3, the acid value is reduced to below 40 mg KOH / g.

[0022] Example 7 The method for synthesizing alkyd resin using elaiolic acid in this embodiment is based on Example 1, and is different from Example 1 in that: in step S1, elaiolic acid, polyol and fatty acid are mixed in a molar ratio of 1:2.1:0.9, the polyol is glycerol, pentaerythritol, sorbitol, ethylene glycol, and trimethylolpropane in a mass ratio of 1:1:1:1:1, and the fatty acid is vegetable oleic acid and animal oleic acid in a mass ratio of 1:1; in step S2, the temperature is heated to 195° C., the pH is controlled at 6, and the pressure is controlled at 0.55 MPa; in step S3, the acid value is reduced to below 24 mg KOH / g.

Claims

1. A method for synthesizing alkyd resin using elaiolic acid, characterized in that The following steps are involved: S1. Mix elaeis acid, polyol and fatty acid in a molar ratio of 1:1.2-3:0.6-1.2 and put into a reaction kettle; S2. Under stirring conditions, gradually heat to 160°C~230°C and maintain the reaction temperature to carry out esterification reaction. During the esterification reaction, the water removal rate is controlled by continuous dehydration to promote the reaction; S3. After the reaction is completed, stop heating and cool to room temperature to obtain an alkyd resin product.

2. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that The polyol is one or more of glycerol, pentaerythritol, sorbitol, ethylene glycol and trimethylolpropane.

3. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that The fatty acid is one or more of vegetable oleic acid and animal oleic acid.

4. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that The esterification reaction time is 4h~8h, and the reaction of step S3 is completed when the acid value of the reaction drops below 8mg KOH / g~40mg KOH / g.

5. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that The pH of the esterification reaction is controlled at 5~7.

6. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that The esterification reaction pressure is controlled at 0.1Mpa~1.0Mpa.

7. The method for synthesizing alkyd resin using elaiophyllic acid according to claim 1, characterized in that An antioxidant, a preservative or a plasticizer is added to the alkyd resin product obtained in step S3.