Fatty acid ester based plasticizer as well as preparation method and application thereof

Abstract

The invention discloses a fatty acid ester-based plasticizer as well as a preparation method and application thereof, and belongs to the technical field of polymer processing aids. The fatty acid ester based plasticizer is high in boiling point, good in stability, non-toxic, green and environment-friendly, and is a perfect substitute for traditional benzene plasticizers. According to the plasticizer, the compatibility with PVC is improved, meanwhile, the thermal stability and mechanical performance of the plasticizer are improved, and the compatibility with PVC is improved, so that the migration rate of the plasticizer in a PVC matrix is remarkably reduced. Meanwhile, the prepared plasticizer is added into PLA for plastification modification, so that the plasticizer has excellent mechanical properties, and the application of the plasticizer in the packaging field is expanded.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer processing aids, and in particular relates to a fatty acid ester-based plasticizer and a preparation method and application thereof. Background Art

[0002] Plasticizers are a class of polymer material additives widely used in industrial production. They can increase the plasticity of polymers, thereby improving the processing properties and physical properties of materials. The mechanism of action of plasticizers is mainly to increase the mobility of polymer molecular chains and reduce the crystallinity of polymer molecular chains by weakening the secondary bonds between polymer molecules, thereby improving the plasticity of polymers. This is manifested in the decrease of hardness, modulus, softening temperature and brittle temperature of polymers, while the elongation, flexibility and toughness are improved. At present, hundreds of plasticizers have been introduced, among which phthalates are the most widely used plasticizers (e.g. dioctyl phthalate) due to their good plasticizing effect and relatively low cost, accounting for more than 80% of the total amount of plasticizers. However, commercial phthalate plasticizers will migrate from the inside of the product to the surface during use and eventually enter the surrounding environment, thereby polluting the environment and having a negative impact on human health, such as disrupting the endocrine system and causing cancer. With the introduction of relevant policies, it is crucial to develop new green plasticizers that are non-toxic, highly resin compatible, low-cost, and have strong plasticizing ability to replace traditional plasticizers.

[0003] Fatty acid ester is one of the derivatives of oil and fat. Because it can be used as automobile fuel, it has long become a research hotspot. However, only fatty acid esters with long alkyl chains are used as plasticizers for PVC products. Due to poor compatibility with PVC resin, it is easy to precipitate from PVC products and can only be added in small amounts as auxiliary plasticizers. CN117986692A discloses a method for preparing an acetoxy fatty acid methyl ester environmentally friendly plasticizer. Refined diesel is sulfonated with sulfuric acid and then hydrolyzed to obtain a mixture containing hydroxy fatty acid methyl esters; then acetylated with acetic anhydride under the action of a catalyst to obtain a mixture containing acetoxy fatty acid methyl esters; after purification, the mixture is allowed to stand for stratification to obtain an upper oil layer; and the oil layer is washed to obtain the acetoxy fatty acid methyl ester environmentally friendly plasticizer. The plasticizer not only has high plasticizing efficiency, low volatility, good compatibility with PVC, but also has excellent low-temperature softness. However, the thermal stability and mechanical properties of the PVC products plasticized by the plasticizer are poor.

[0004] CN110627643A discloses a method for preparing an environmentally friendly plasticizer using waste oil. The invention adopts higher fatty acids, methanol, 50% hydrogen peroxide, trimellitic anhydride and acetic anhydride purified from waste oil as main raw materials, and carries out molecular structure transformation and functional group conversion through four-step reactions of esterification, epoxidation, ring-opening esterification and acetylation to obtain an environmentally friendly plasticizer product, acetyl fatty acid methyl ester-trimellitic acid ester. The environmentally friendly plasticizer product prepared by the invention has the characteristics of a combination of cyclic molecules and linear molecules at the same time, the product has moderate viscosity, yellow color, good migration resistance and heat resistance, is suitable for industrial production, and is expected to replace traditional phthalate plasticizers. However, this type of plasticizer is a tribasic acid ester structure with a relatively large molecular weight, and the tribasic ester structure has a large steric hindrance, the obtained PVC product has strong rigidity, poor flexibility, and insufficient mechanical properties; and trimellitic anhydride is not a bio-based raw material, and the obtained plasticizer has a relatively large molecular weight and a relatively large viscosity. Summary of the invention

[0005]

Technical issues

[0006] The invention aims at the problems of poor compatibility, high volatility, poor flexibility, and insufficient thermal stability and mechanical properties of bio-based plasticizer plasticized PVC materials. A preparation method and application of a fatty acid ester-based plasticizer are provided. The fatty acid ester-based plasticizer with excellent performance is prepared by using fatty acid ester, natural organic acid and acetic anhydride as raw materials. The fatty acid ester-based plasticizer contains a long fatty chain structure, a benzene ring structure, a multi-ester structure and a short ester branched structure. The compatibility of the plasticizer with PVC is increased while the thermal stability, mechanical properties and migration resistance of the plasticizer are increased.

[0007]

Technical solution

[0008] The present invention provides a fatty acid ester-based plasticizer, the structure of which is shown in the following general formula (A1), (A2), or (A3):

[0009]

[0010] In the formula, R 1 C 1-10 alkyl;

[0011] n1 is -CH on the fatty chain 2 - is 1, 2, 3, 4, 5, 6, 7 or 8;

[0012] n2 is a substituent R on the benzene ring 2 The number of substitutions is 1, 2, 3 or 4;

[0013] Each R 2 are independently selected from -O-C1-4 alkyl, -O-CO-C 1-4 alkyl;

[0014] n3 is -CH on the fatty chain 2 - is 1, 2, 3, 4, 5, 6, 7 or 8;

[0015] n4 is -CH on the fatty chain 2 - is 1, 2, 3, 4, 5, 6, 7 or 8;

[0016] n5 is -CH on the fatty chain 2 - is 1, 2, 3, 4, 5, 6, 7 or 8.

[0017] In an embodiment of the present invention, there is at least one -O-CO-C 1-4 Alkyl substitution.

[0018] In an embodiment of the present invention, the structure of the fatty acid ester-based plasticizer may be:

[0019]

[0020] R 1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, decyl;

[0021] R 2 , R 3 , R 4 , R 5 Each of them is independently selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, acetoxy, propionyloxy and butyryloxy; and the rest are hydrogen.

[0022] In an embodiment of the present invention, R 2 , R 3 , R 4 , R 5 At least one of them is selected from -O-CO-C 1-4 Alkyl substituted; the rest are arbitrarily selected from: hydrogen, -O-C1-4 alkyl, or -O-CO-C 1-4 Alkyl substitution.

[0023] In an embodiment of the present invention, further, R 2 , R 3 , R 4 , R 5 At least one of them is selected from acetoxy; the rest are hydrogen or methoxy.

[0024] The fatty acid ester-based plasticizer of the present invention is mainly composed of a long fatty chain structure, a benzene ring structure, a polyester structure and a short ester branched chain structure.

[0025] The present invention provides a method for preparing the fatty acid ester-based plasticizer, wherein fatty acid ester, natural organic acid and acetic anhydride are used as main raw materials to obtain the plasticizer through three steps of epoxidation, ring-opening esterification and acetylation, and the specific steps are as follows:

[0026] Epoxy fatty acid ester is prepared by epoxidation reaction with fatty acid ester and catalyst 1 as raw materials; fatty acid ester-organic acid ester is prepared by ring-opening reaction of the obtained epoxy fatty acid ester with natural organic acid and ring-opening agent; finally, fatty acid ester-organic acid ester, acetic anhydride and catalyst 2 are acetylated to obtain the corresponding fatty acid ester-based plasticizer.

[0027] In an embodiment of the present invention, the fatty acid ester is a fatty acid ester containing 1 to 3 unsaturated double bonds.

[0028] In an embodiment of the present invention, the fatty acid ester is specifically selected from: at least one of methyl oleate, ethyl oleate, butyl oleate, hexyl oleate, octyl oleate, decyl oleate, methyl linoleate, ethyl linoleate, butyl linoleate, hexyl linoleate, octyl linoleate, decyl linoleate, methyl linoleate, ethyl linoleate, butyl linoleate, hexyl linoleate, octyl linoleate and decyl linoleate.

[0029] In an embodiment of the present invention, the natural organic acid is any one of salicylic acid, vanillic acid, syringic acid, gentisic acid, protocatechuic acid and gallic acid.

[0030] In an embodiment of the present invention, the catalyst 1 is any one of m-chloroperbenzoic acid and hydrogen peroxide.

[0031] In an embodiment of the present invention, the ring-opening agent is any one of tetrabutylammonium chloride and tetrabutylammonium bromide.

[0032] In an embodiment of the present invention, the catalyst 2 is any one of a strongly acidic cation exchange resin and concentrated sulfuric acid.

[0033] In an embodiment of the present invention, in the epoxidation reaction, the molar ratio of the fatty acid ester to the catalyst 1 is 1:1.2-3.2.

[0034] In an embodiment of the present invention, in the epoxidation reaction, fatty acid ester and m-chloroperbenzoic acid are dissolved in dichloromethane, first reacted in an ice-water bath and then reacted at room temperature, washed to neutrality after the reaction, purified and dried to obtain the product epoxy fatty acid ester.

[0035] In an embodiment of the present invention, in the epoxidation reaction, an acidic ion exchange resin and formic acid are added to the fatty acid ester, and then hydrogen peroxide is added dropwise to react to obtain the epoxy fatty acid ester.

[0036] In an embodiment of the present invention, during the ring-opening reaction, the molar ratio of the epoxy fatty acid ester to the natural organic acid is 1:1.4-4.5.

[0037] Furthermore, if the fatty acid ester is a fatty acid ester containing one unsaturated double bond, the molar ratio of the epoxy fatty acid ester to the natural organic acid is 1:1.4-2.5; if the fatty acid ester is a fatty acid ester containing two unsaturated double bonds, the molar ratio of the epoxy fatty acid ester to the natural organic acid is 1:2.0-3.5; if the fatty acid ester is a fatty acid ester containing three unsaturated double bonds, the molar ratio of the epoxy fatty acid ester to the natural organic acid is 1:3.0-4.5.

[0038] In an embodiment of the present invention, during the ring-opening reaction, the amount of the ring-opening agent added is 0.1 wt%-5 wt% of the mass of the epoxy fatty acid ester, and can further be 4 wt%-5 wt%.

[0039] In an embodiment of the present invention, during the ring-opening reaction, the epoxy fatty acid ester, natural organic acid and ring-opening agent are mixed and heated to 120-140° C., and the reaction is continued for 4-7 hours. After the reaction is completed, the mixture is washed to neutrality, purified and dried to obtain the product fatty acid ester-organic acid ester.

[0040] In an embodiment of the present invention, in the acetylation reaction, the amount of acetic anhydride added is 50 wt % to 90 wt % of the fatty acid ester-organic acid ester.

[0041] In an embodiment of the present invention, in the acetylation reaction, the added amount of the catalyst 2 is 5 wt % to 15 wt % of the fatty acid ester-organic acid ester.

[0042] In an embodiment of the present invention, in the acetylation reaction, the fatty acid ester-organic acid ester, acetic anhydride and catalyst 2 are mixed and heated to 60°C to 90°C, and the reaction is continued for 18 to 24 hours. After the reaction is completed, the mixture is washed to neutrality, purified and dried to obtain the final product, a fatty acid ester-based plasticizer.

[0043] The present invention also provides the use of the fatty acid ester-based plasticizer as a main plasticizer in the preparation of polymer materials.

[0044] The polymer material includes PVC or polyester material and the like.

[0045]

Beneficial Effects

[0046] (1) The present invention utilizes the special structure (carboxyl and hydroxyl) of natural organic acids and the ring-opening reaction of epoxy fatty acid esters to prepare a plasticizer having a long fatty chain structure, a benzene ring structure, a polyester structure, and a short ester branched structure; while improving its compatibility with PVC, it also improves the tensile strength, elongation at break, thermal stability, and migration resistance of the PVC material.

[0047] (2) The non-polar long alkyl chain is inserted into PVC to increase the free volume and play a lubricating role. The presence of the cyclic benzene ring structure improves the compatibility of the plasticizer with PVC while increasing its thermal stability and mechanical properties. The multiple polar ester groups contained in it produce dipole-dipole interactions with the α-H on the polar PVC molecules, which offset part of the interaction between PVC and increase the compatibility with PVC. The short ester branched structure increases the interaction and physical interpenetration between molecules, and the mobility of the plasticizer in the PVC matrix is ​​significantly reduced, which can replace the traditional phthalate plasticizers.

[0048] (3) The raw materials used in the present invention are derived from bio-based materials, which are green and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is the infrared spectrum of the acetyloleic acid methyl ester-salicylate product of Example 1;

[0050] Figure 2 The thermogravimetric curves of the product acetyl oleate methyl salicylate of Example 1 and the comparative plasticizers; the comparative plasticizers include: methyl oleate, diisononyl cyclohexane-1,2-dicarboxylate (DINCH), plasticizer A, plasticizer B and plasticizer C;

[0051] Figure 3 The color changes of PVC samples of Comparative Examples 1-5 and Application Example 1 at 200°C over time. DETAILED DESCRIPTION

[0052] The present invention is described in detail below in conjunction with the accompanying drawings and embodiments.

[0053] Example 1

[0054] (R 1 =Me, R 2 =-O-COCH 3 , R 3 =R 4 =R 5 =H)

[0055] The specific preparation process is as follows:

[0056] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy methyl oleate;

[0057] (2) adding 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 33 g (0.24 mol) of salicylic acid and 2 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating them to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase at -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-salicylate;

[0058] (3) Add 50 g of the product of step (2), 35 g of acetic anhydride and 5 g of a strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, first remove the acetic anhydride by vacuum distillation at -0.1 MPa and 120° C., then wash with deionized water until neutral, and then remove water by vacuum distillation at -0.1 MPa and 75° C. to obtain the final product, fatty acid ester-based plasticizer methyl acetyl oleate-salicylate.

[0059] The product acetyloleic acid methyl ester-salicylate in Example 1 was tested by infrared spectrum, and the test results are as follows: Figure 1 shown.

[0060] Figure 1 From top to bottom are epoxy oleic acid methyl ester, oleic acid methyl ester-salicylate and the final product acetyl oleic acid methyl ester-salicylate. In the first step of the epoxidation reaction, the infrared curve of epoxy oleic acid methyl ester at 928cm -1 The formation of epoxy bond (COC) proved the successful preparation of epoxy oleic acid methyl ester. Subsequently, the stretching vibration peak of epoxy bond (COC) in the infrared curve of methyl oleate-salicylate disappeared, and the peak at 3493 cm -1 The appearance of the stretching vibration peak of the hydroxyl group (-OH) at 3493 cm -1 The stretching vibration peak of the hydroxyl group (-OH) disappeared, which proved that the acetylation reaction was successful and acetyl oleate methyl ester-salicylate was successfully synthesized.

[0061] Example 2

[0062] (R 1 =Me, R 3 =OMe, R 4 =-O-COCH 3 , R 2 =R 5 =H)

[0063] The specific preparation process is as follows:

[0064] (1) 40 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy methyl oleate;

[0065] (2) 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 40 g (0.24 mol) of vanillic acid and 0.1 g of tetrabutylammonium chloride are added to a reactor under a nitrogen atmosphere, the above raw materials are mixed and heated to 140° C., and the reaction is continued for 5 hours. After the reaction is completed, the organic phase is washed with deionized water until neutral, and the organic phase is vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-vanillate;

[0066] (3) 50 g of the product of step (2), 25 g of acetic anhydride and 2.5 g of a strongly acidic cation exchange resin are added to a reactor, the raw materials are mixed and heated to 85° C., and the reaction is continued for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., and then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, a fatty acid ester-based environmentally friendly plasticizer, acetyl oleic acid methyl ester-vanillate.

[0067] Example 3

[0068] (R 1 =Me, R 3 =R 5 =OMe, R 4 =-O-COCH 3 , R 2 =H)

[0069] The specific preparation process is as follows:

[0070] (1) 43 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy methyl oleate;

[0071] (2) 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 48 g (0.24 mol) of syringic acid and 1 g of tetrabutylammonium chloride are added to a reactor under a nitrogen atmosphere, the raw materials are mixed and heated to 140° C., and the reaction is continued for 5 hours. After the reaction is completed, the organic phase is washed with deionized water until neutral, and the organic phase is vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-syringate;

[0072] (3) 50 g of the product of step (2) methyl oleate-syringate, 40 g of acetic anhydride and 7.5 g of a strongly acidic cation exchange resin are added to a reactor, the raw materials are mixed and heated to 85° C., and the reaction is continued for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., and then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, fatty acid ester-based environmentally friendly plasticizer acetyl oleate methyl syringate.

[0073] Example 4

[0074] (R 1 =Me, R 2 =R 5 =-O-COCH 3 , R 3 =R 4 =H)

[0075] The specific preparation process is as follows:

[0076] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy methyl oleate;

[0077] (2) adding 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 37 g (0.24 mol) of gentisic acid and 2.5 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating them to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase at -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-gentisate;

[0078] (3) Add 50 g of the product of step (2) methyl oleate-gentisate, 35 g of acetic anhydride and 5 g of strongly acidic cation exchange resin into a reactor, mix the above raw materials and heat them to 85° C., and continue the reaction for 24 hours. After the reaction is completed, the acetic anhydride is first removed by reduced pressure distillation at -0.1 MPa and 120° C., then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, fatty acid ester-based environmentally friendly plasticizer acetyl oleate methyl gentisate.

[0079] Example 5

[0080] (R 1 =Me, R 3 =R 4 =-O-COCH 3 , R 2 =R 5 =H)

[0081] The specific preparation process is as follows:

[0082] (1) 80 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl linoleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product methyl epoxylinoleate;

[0083] (2) 50 g (0.16 mol) of the product methyl epoxylinoleate obtained in step (1), 52.36 g (0.34 mol) of protocatechuic acid and 2 g of tetrabutylammonium chloride were added to a reactor under a nitrogen atmosphere, the above raw materials were mixed and heated to 140° C., and the reaction was continued for 5 hours. After the reaction was completed, the organic phase was washed with deionized water until neutral, and the organic phase was vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product methyl linoleate-protocatechuate;

[0084] (3) Add 50 g of the product of step (2) methyl linoleate-protocatechuate, 40 g of acetic anhydride and 5 g of strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, first remove the acetic anhydride by vacuum distillation at -0.1 MPa and 120° C., then wash with deionized water to neutrality, and then remove water by vacuum distillation at -0.1 MPa and 75° C. to obtain the final product, fatty acid ester-based environmentally friendly plasticizer methyl acetyllinoleate-protocatechuate.

[0085] Example 6

[0086] (R 1 =Me, R 2 =H, R 3 =R 4 =R 5 =-O-COCH 3 )

[0087] The specific preparation process is as follows:

[0088] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of methyl linolenate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product methyl epoxylinolenate;

[0089] (2) 50 g (0.16 mol) of the product methyl epoxylinolenate obtained in step (1), 85 g (0.50 mol) of gallic acid and 1 g of tetrabutylammonium chloride are added to a reactor under a nitrogen atmosphere, the above raw materials are mixed and heated to 140° C., and the reaction is continued for 5 hours. After the reaction is completed, the organic phase is washed with deionized water until neutral, and the organic phase is vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product methyl linolenate-gallate;

[0090] (3) Add 50 g of the product of step (2), 45 g of acetic anhydride and 5 g of a strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, first remove the acetic anhydride by vacuum distillation at -0.1 MPa and 120° C., then wash with deionized water to neutrality, and then remove water by vacuum distillation at -0.1 MPa and 75° C. to obtain the final product, fatty acid ester-based environmentally friendly plasticizer methyl acetyl linolenate-gallate.

[0091] Example 7

[0092] (R 1 = n-butyl, R 2 =-O-COCH 3 , R 3 =R 4 =R 5 =H)

[0093] The specific preparation process is as follows:

[0094] (1) 30 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of butyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy butyl oleate;

[0095] (2) adding 50 g (0.14 mol) of the product butyl oleate obtained in step (1), 28.9 g (0.21 mol) of salicylic acid and 2 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating them to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase at -0.1 MPa and 75° C. to remove water to obtain the product butyl oleate-salicylate;

[0096] (3) 50 g of the product of step (2), 35 g of acetic anhydride and 2.5 g of a strongly acidic cation exchange resin are added to a reactor, the raw materials are mixed and heated to 85° C., and the reaction is continued for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., and then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, fatty acid ester-based plasticizer acetyl butyl oleate-salicylate.

[0097] Example 8

[0098] (R 1 = hexyl, R 3 =OMe, R 4 =-O-COCH 3 , R 2 =R 5 =H)

[0099] The specific preparation process is as follows:

[0100] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of hexyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy hexyl oleate;

[0101] (2) adding 50 g (0.13 mol) of the product epoxidized hexyl oleate obtained in step (1), 31.9 g (0.19 mol) of vanillic acid and 1.5 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating them to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase under -0.1 MPa and 75° C. to remove water to obtain the product hexyl oleate-vanillate;

[0102] (3) Add 50 g of the product of step (2) hexyl oleate-vanillate, 35 g of acetic anhydride and 7.5 g of strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, first remove the acetic anhydride by vacuum distillation at -0.1 MPa and 120° C., then wash with deionized water to neutrality, and then vacuum distill to remove water at -0.1 MPa and 75° C. to obtain the final product, fatty acid ester-based environmentally friendly plasticizer hexyl oleate-vanillate.

[0103] Example 9

[0104] (R 1 =Octyl, R 3 =R 5 =OMe, R 4 =-O-COCH 3 , R 2 =H)

[0105] The specific preparation process is as follows:

[0106] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of octyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy octyl oleate;

[0107] (2) 50 g (0.12 mol) of the product octyl epoxy oleate obtained in step (1), 39.4 g (0.20 mol) of syringic acid and 2 g of tetrabutylammonium chloride are added to a reactor under a nitrogen atmosphere, the raw materials are mixed and heated to 140° C., and the reaction is continued for 5 hours. After the reaction is completed, the organic phase is washed with deionized water until neutral, and the organic phase is vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product octyl oleate-syringate;

[0108] (3) 50 g of the product of step (2), 35 g of acetic anhydride and 2.5 g of a strongly acidic cation exchange resin are added to a reactor, the raw materials are mixed and heated to 85° C., and the reaction is continued for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., and then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, fatty acid ester-based environmentally friendly plasticizer acetyl oleate-syringate.

[0109] Example 10

[0110] (R 1 =Decyl, R 2 =R 5 =-O-COCH 3 , R 3 =R 4 =H)

[0111] The specific preparation process is as follows:

[0112] (1) 37 g of m-chloroperbenzoic acid was dissolved in 150 mL of dichloromethane and stirred under ice-water bath conditions, and then 100 mL of dichloromethane solution containing 50 g of decyl oleate was added dropwise to the above system, and the above raw materials were first reacted in an ice-water bath for 0.5 h, and then reacted at room temperature for 24 h. After the reaction, the mixture was washed with sodium thiosulfate solution and sodium bicarbonate solution until neutral, and then washed with sodium chloride solution for 3 times, and finally washed with deionized water for 3 times, and then dichloromethane was removed by vacuum distillation at -0.1 MPa and 35° C. to obtain the product epoxy decyl oleate;

[0113] (2) adding 50 g (0.11 mol) of the product epoxy oleic acid decyl ester obtained in step (1), 27.7 g (0.18 mol) of gentisic acid and 2 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase under -0.1 MPa and 75° C. to remove water to obtain the product oleic acid decyl ester-gentisic acid ester;

[0114] (3) Add 50 g of the product of step (2), 35 g of acetic anhydride and 5 g of a strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, a fatty acid ester-based environmentally friendly plasticizer, acetyl oleic acid decyl ester-gentisate.

[0115] Embodiment 11

[0116] (R 1 =Me, R 3 =OMe, R 4 =-O-COCH 3 , R 2 =R 5 =H)

[0117] The specific preparation process is as follows:

[0118] (1) adding 0.5 g of formic acid and 0.05 g of an acidic ion exchange resin to 50 g of methyl oleate, and dripping 35% hydrogen peroxide at 60-75° C. while stirring. The dripping is completed within 4 hours, and then reacting for another hour. After the reaction is completed, the mixture is cooled to below 50° C., washed with sodium carbonate solution and deionized water until neutral, and then vacuum distilled at -0.1 MPa and 100° C. to remove impurities to obtain the product epoxy methyl oleate;

[0119] (2) 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 37 g (0.24 mol) of protocatechuic acid and 2 g of tetrabutylammonium chloride were added to a reactor under a nitrogen atmosphere, the raw materials were mixed and heated to 140° C., and the reaction was continued for 5 h. After the reaction was completed, the organic phase was washed with deionized water until neutral, and the organic phase was vacuum distilled under -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-protocatechuate;

[0120] (3) 50 g of the product of step (2) methyl oleate-protocatechuate, 35 g of acetic anhydride and 7.5 g of a strongly acidic cation exchange resin are added to a reactor, the above raw materials are mixed and heated to 85° C., and the reaction is continued for 24 hours. After the reaction is completed, the acetic anhydride is first removed by vacuum distillation at -0.1 MPa and 120° C., and then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 75° C. to remove water to obtain the final product, fatty acid ester-based environmentally friendly plasticizer methyl acetyl oleate-protocatechuate.

[0121] Example 12

[0122] (R 1 =Me, R 2 =H, R 3 =R 4 =R 5 =-O-COCH 3 )

[0123] The specific preparation process is as follows:

[0124] (1) adding 0.5 g of formic acid and 0.05 g of an acidic ion exchange resin to 50 g of methyl oleate, and dripping 35% hydrogen peroxide at 60-75° C. while stirring. The dripping is completed within 4 hours, and then reacting for another hour. After the reaction is completed, the mixture is cooled to below 50° C., washed with sodium carbonate solution and deionized water until neutral, and then vacuum distilled at -0.1 MPa and 100° C. to remove impurities to obtain the product epoxy methyl oleate;

[0125] (2) adding 50 g (0.16 mol) of the product methyl oleate obtained in step (1), 41 g (0.24 mol) of gallic acid and 2 g of tetrabutylammonium chloride into a reactor under a nitrogen atmosphere, mixing the above raw materials and heating them to 140° C., and continuing the reaction for 5 h. After the reaction is completed, washing with deionized water until neutral, and then vacuum distilling the organic phase at -0.1 MPa and 75° C. to remove water to obtain the product methyl oleate-gallate;

[0126] (3) Add 50 g of the product of step (2), 35 g of acetic anhydride and 5 g of a strongly acidic cation exchange resin into a reactor, mix the above raw materials, heat to 85° C., and continue the reaction for 24 hours. After the reaction is completed, first remove the acetic anhydride by vacuum distillation at -0.1 MPa and 120° C., then wash with deionized water to neutrality, and then remove water by vacuum distillation at -0.1 MPa and 75° C. to obtain the final product, fatty acid ester-based environmentally friendly plasticizer acetyl oleic acid methyl ester-gallate.

[0127] Application Examples

[0128] N 2 The carrier gas is 50 mL / min in flow rate, the test temperature range is 100-550°C, the heating rate is 20°C / min, and the sample mass is 5-10 mg for thermogravimetric analysis of plasticizers and plasticized materials.

[0129] The mechanical properties of the materials were tested according to GB / T 1040-2006, the tensile rate was 50 mm / min, and five samples were tested in parallel in each group.

[0130] According to GB / T9349-2002 Polyvinyl chloride, related chlorine-containing homopolymers and copolymers and their blends - Determination of thermal stability - Color change method, observe and record the color change of the sample. By observing the color change of PVC samples at 200°C over time, the stability and aging speed of thermal PVC products can be judged.

[0131] According to the standard "ISO 176-2005 activated carbon adsorption method", PVC samples with a size of 20×20×1.0mm were completely buried in ceramic crucibles filled with activated carbon powder, and then the ceramic crucibles were placed in a forced air hot oven at a temperature of 100±1℃. After 24 hours, the samples were taken out to test their mass loss. The initial mass of the sample was weighed, recorded as W0; at the end of the test, the sample was weighed, recorded as W. Each group of tests was performed three times in parallel to obtain the average value as the final loss rate result. The volatile mass loss rate of the PVC sample was calculated by formula (1),

[0132] Application 1: Weigh 40 parts by weight of plasticizer, 100 parts by weight of PVC paste resin powder and 3 parts by weight of calcium zinc heat stabilizer, mix them at room temperature for pre-plasticization, then melt blend at 160°C, and finally hot-press the sample at 170°C to obtain a PVC film of uniform thickness.

[0133] The plasticizers include the fatty acid ester-based plasticizers prepared in Examples 1-12 shown in Table 1, the comparative plasticizer methyl oleate, diisononyl cyclohexane-1,2-dicarboxylate (DINCH), plasticizer A, plasticizer B, and plasticizer C.

[0134] The performance test results of the obtained PVC film are shown in Table 1.

[0135] Table 1

[0136]

[0137]

[0138] Table T d-50％ It indicates the thermal degradation temperature corresponding to 50% mass loss of plasticized PVC film.

[0139] Among them, plasticizer A represents benzyl oleate, which can be prepared by the following method: 50g of oleic acid, 18.8g of benzyl alcohol, 0.85g of p-toluenesulfonic acid and 13.5g of toluene, continue to react for 10-12h in a nitrogen environment at 130°C. After the reaction, wash the crude product with NaHCO3 solution and deionized water; finally, distill the crude product under reduced pressure to fully remove residual water and solvent in the crude product to obtain benzyl oleate.

[0140] Plasticizer B represents the acetoxy fatty acid methyl ester mentioned in the prior art document CN117986692A (Example 6 in the document).

[0141] Plasticizer C was prepared according to the method of Reference Example 1, except that salicylic acid was replaced with benzoic acid to obtain acetyloleic acid methyl ester-benzoate.

[0142] Application 2: 10 parts of plasticizer and 100 parts of PLA were weighed, melt-blended at 180°C, and the sample was further hot-pressed at 190°C to obtain a film with uniform thickness. The performance test results of the obtained film are shown in Table 2.

[0143] Table 2

[0144]

[0145]

[0146] Function and effect:

[0147] From the data in Table 1, it can be seen that the tensile strength, elongation at break (plasticizing efficiency) and volatility resistance of the PVC materials plasticized by the fatty acid ester-based plasticizers prepared in Examples 1-12 are much better than those of methyl oleate, environmentally friendly plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and PVC plasticized by the currently reported plasticizers A, B, and C; when the mass loss is 50%, the degradation temperature corresponding to the plasticized PVC in Examples 1-12 is higher than that of the comparative sample, indicating that the PVC samples plasticized by the fatty acid ester-based environmentally friendly plasticizers show better thermal stability. This is because fatty acid ester-based environmentally friendly plasticizers have a long fatty chain structure, a benzene ring structure, a multi-ester structure and a short ester branched structure. The non-polar long alkyl chain is inserted into PVC to increase the free volume and act as a lubricant. The presence of the ring structure improves the compatibility of the plasticizer with PVC while increasing its thermal stability and mechanical properties. The multiple polar ester groups contained in it produce dipole-dipole interactions with the α-H on the polar PVC molecules, which offset part of the interaction force between PVC, increase compatibility with PVC, and the short ester branched structure increases the interaction and physical interpenetration between molecules, and the volatility of the plasticizer in the PVC matrix is ​​significantly reduced.

[0148] From the data in Table 2, it can be seen that the tensile strength of pure PLA is generally 65.1MPa, and the elongation at break is 6.3%. Compared with pure PLA, the elongation at break of PLA composite film increases after adding 10 parts of plasticizer. Compared with methyl oleate, adding 10 parts of fatty acid ester-based plasticizer prepared in Examples 1-12 can improve both strength and toughness.

[0149] Thermogravimetric analysis was performed on eight plasticizers, including methyl oleate, diisononyl cyclohexane-1,2-dicarboxylate (DINCH), plasticizer A, plasticizer B, plasticizer C, and plasticizers prepared in Example 1, Example 5, and Example 6 of the present invention. The results are as follows: Figure 2 As shown in Table 3, when the mass loss is 50%, the degradation temperature of acetyl fatty acid ester-salicylic acid ester is higher than that of other plasticizers.

[0150] Table 3

[0151]

[0152]

[0153] Table T d-50％ It indicates the thermal degradation temperature when the mass loss of plasticizer is 50%.

[0154] It is shown that the fatty acid ester-based plasticizer synthesized by the present invention has higher thermal stability, because the fatty acid ester only contains a long fatty chain structure and has a small molecular weight, so its thermal stability is the worst; oleic acid benzyl alcohol ester contains a benzene ring structure, an ester group and a long chain structure, so its thermal stability is relatively high; the environmentally friendly plasticizer cyclohexane-1,2-diisononyl dicarboxylate contains a six-membered ring, two ester groups and two long fatty chains, and its thermal stability is relatively high; acetyl fatty acid ester-salicylic acid ester contains a benzene ring structure, a long fatty chain structure, multiple ester groups and a short ester branched chain structure and its molecular weight is higher than that of other plasticizers, so its thermal stability is the best.

[0155] The color change of the PVC samples at 200°C over time was observed. Comparative Example 1 turned black within 5 minutes, and a large number of small bubbles were generated on the surface. Its thermal stability was very poor and hydrogen chloride was released during the heating process. Comparative Example 2 slowly turned yellow in about 10 minutes, and turned black after 40 minutes without small bubbles on the surface. Comparative Example 3 turned black in about 10 minutes and a large number of small bubbles were generated on the surface. Comparative Example 4 slowly turned black after 5 minutes. Comparative Example 5 slowly turned yellow after 20 minutes, and turned black after 40 minutes without small bubbles on the surface. Example 1 did not turn black until 50 minutes later and no small bubbles were generated on the surface, and had very good color retention and heat aging properties. This is because fatty acid ester-based environmentally friendly plasticizers have a long fatty chain structure, a benzene ring structure, a multi-ester structure and a short ester branched structure. The non-polar long alkyl chain is inserted into PVC to increase the free volume and act as a lubricant. The presence of the ring structure improves the compatibility of the plasticizer with PVC while increasing its thermal stability and mechanical properties. The multiple polar ester groups contained in it produce dipole-dipole interactions with the α-H on the polar PVC molecules, which offset part of the interaction force between PVCs and increase compatibility with PVC. The short ester branched structure increases the interaction and physical interpenetration between molecules, so fatty acid ester-based environmentally friendly plasticizers have the best color retention and thermal aging properties.

[0156] The embodiments provided above are not intended to limit the scope of the present invention, and the steps described are not intended to limit the execution order thereof. Those skilled in the art may make obvious improvements to the present invention in combination with existing common knowledge, which also fall within the scope of protection defined by the claims of the present invention.

Claims

1. A fatty acid ester-based plasticizer, characterized in that: Its structure is shown in the following general formula (A1), (A2), or (A3): In the formula, R1 is C 1-10 alkyl; n1 is the number of -CH2- groups on the aliphatic chain, which is 1, 2, 3, 4, 5, 6, 7 or 8; n2 is the number of substituents R2 on the benzene ring, which is 1, 2, 3 or 4; Each R2 is independently selected from -O-C1-4 alkyl, -O-CO-C 1-4 alkyl; n3 is the number of -CH2- groups on the aliphatic chain, which is 1, 2, 3, 4, 5, 6, 7 or 8; n4 is the number of -CH2- groups on the aliphatic chain, which is 1, 2, 3, 4, 5, 6, 7 or 8; n5 is the number of -CH2- on the aliphatic chain, which is 1, 2, 3, 4, 5, 6, 7 or 8.

2. The fatty acid ester-based plasticizer according to claim 1, characterized in that The structure of the fatty acid ester-based plasticizer is specifically: R1 is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, hexyl, heptyl, octyl, decyl; R2, R3, R4, and R5 are independently selected from methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, tert-butoxy, acetoxy, propionyloxy, and butyryloxy; and the rest are hydrogen.

3. The fatty acid ester-based plasticizer according to claim 1, characterized in that The structure of the fatty acid ester-based plasticizer is specifically: R1 is C 1-10 alkyl; At least one of R2, R3, R4 and R5 is selected from acetoxy, and the others are hydrogen or methoxy.

4. A method for preparing a fatty acid ester-based plasticizer according to any one of claims 1 to 3, characterized in that: The plasticizer is obtained by using fatty acid ester, natural organic acid and acetic anhydride as main raw materials through three steps of epoxidation, ring-opening esterification and acetylation, including the following steps: Epoxy fatty acid ester is prepared by epoxidation reaction with fatty acid ester and catalyst 1 as raw materials; fatty acid ester-organic acid ester is prepared by ring-opening reaction of the obtained epoxy fatty acid ester with natural organic acid and ring-opening agent; finally, fatty acid ester-organic acid ester, acetic anhydride and catalyst 2 are acetylated to obtain the corresponding fatty acid ester-based plasticizer.

5. The preparation method according to claim 4, characterized in that: The fatty acid ester is at least one of methyl oleate, ethyl oleate, butyl oleate, hexyl oleate, octyl oleate, decyl oleate, methyl linoleate, ethyl linoleate, butyl linoleate, hexyl linoleate, octyl linoleate, decyl linoleate, methyl linoleate, ethyl linoleate, butyl linoleate, hexyl linoleate, octyl linoleate and decyl linoleate.

6. The preparation method according to claim 4, characterized in that: The natural organic acid is any one of salicylic acid, vanillic acid, syringic acid, gentisic acid, protocatechuic acid and gallic acid.

7. The preparation method according to claim 4, characterized in that: The catalyst 1 is any one of meta-chloroperbenzoic acid and hydrogen peroxide; the ring-opening agent is any one of tetrabutylammonium chloride and tetrabutylammonium bromide; and the catalyst 2 is any one of strongly acidic cation exchange resin and concentrated sulfuric acid.

8. The preparation method according to claim 4, characterized in that: In the epoxidation reaction, the molar ratio of the fatty acid ester to the catalyst 1 is 1:1.2-3.

2.

9. The preparation method according to claim 4, characterized in that: During the ring-opening reaction, the molar ratio of the epoxy fatty acid ester to the natural organic acid is 1:1.4-4.5; the added amount of the ring-opening agent is 0.1wt%-5wt% of the mass of the epoxy fatty acid ester.

10. The preparation method according to any one of claims 4 to 9, characterized in that: In the acetylation reaction, the amount of acetic anhydride added is 50 wt% to 90 wt% of the fatty acid ester-organic acid ester; the amount of catalyst 2 added is 5 wt% to 15 wt% of the fatty acid ester-organic acid ester.

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