Plant oil-based PVC plasticizer, its preparation method and application

Abstract

The application discloses a vegetable oil-based PVC plasticizer, and structural formula is shown as formula (I), formula (II) or formula (III). The vegetable oil-based PVC plasticizer constructs a core-shell structure with aromatic ring and long-chain fatty acid ester. The rigidity of the aromatic ring is used to improve the mechanical strength of the PVC material as the PVC plasticizer, and the flexibility of the long-chain fatty acid ester is used to improve the toughness of the PVC material. The vegetable oil-based plasticizer has plasticizing performance, heat resistance and low migration rate. The application further discloses a preparation method and application of the vegetable oil-based PVC plasticizer.

Description

Technical Field

[0001] The invention belongs to the technical field of plastic additives, and particularly relates to a plant oil-based PVC plasticizer and a preparation method and application thereof. Background Art

[0002] In recent years, with increasingly stringent environmental regulations and the advancement of sustainable development strategies, the use of traditional petroleum-based plasticizers has been gradually replaced and restricted due to their potential ecotoxicity and bioaccumulation. Polyvinyl chloride (PVC), one of the world's most produced general-purpose plastics, relies heavily on plasticizers to improve the flexibility and processing properties of PVC products. However, existing commercial plasticizers still have significant shortcomings in terms of environmental performance, durability, and plasticizing efficiency, necessitating the development of new, green alternatives.

[0003] Plant oil-based plasticizers have become a current research hotspot due to their renewable raw materials, biodegradability, and low toxicity. Natural oils such as soybean oil, castor oil, and palm oil can be derived into a series of compounds with plasticizing functions through chemical modifications such as epoxidation, esterification, or polymerization. For example, epoxidized vegetable oils such as epoxidized soybean oil have been partially commercialized, but they have poor compatibility with PVC, are prone to migration and precipitation, and have limited effects on improving the low-temperature toughness and thermal stability of PVC. In addition, existing plant oil-based plasticizers generally have problems with low molecular weight and insufficient polarity, which leads to a decrease in the mechanical strength of plasticized PVC products, especially in long-term use. Performance degradation is prone to occur.

[0004] In the existing technology, the performance of vegetable oil-based plasticizers is improved mainly through the following methods: (1) increasing molecular weight and reducing migration through polyol esterification or polymerization reaction; (2) introducing polar groups such as epoxy and hydroxyl groups to enhance interaction with PVC; (3) designing molecules with rigid-flexible synergistic structures to balance plasticizing effect and mechanical properties. However, these methods face bottlenecks such as complex synthesis process, high cost or single modification effect. Vegetable oil-based plasticizers cannot simultaneously achieve plasticizing performance, heat stability and low migration rate. In this context, it is of great significance to develop vegetable oil-based plasticizers with the above effects. Summary of the Invention

[0005] The purpose of the present invention is to provide a vegetable oil-based PVC plasticizer and a preparation method and application thereof, so as to solve the technical problem in the prior art that vegetable oil-based plasticizers cannot have plasticizing performance, heat stability and low mobility.

[0006] According to a first aspect of the present invention, a plant oil-based PVC plasticizer is provided. The structural formula of the plant oil-based PVC plasticizer is shown in Formula (I), Formula (II) or Formula (III):

[0007]

[0008] Formula (I)

[0009]

[0010] Formula (II)

[0011]

[0012] Formula (III);

[0013] Wherein, the structure of Ar in formula (I), formula (II) or formula (III) is 、 、 or .

[0014] The plant oil-based PVC plasticizer of the present invention utilizes an aromatic ring and a long-chain fatty acid ester to construct a core-shell structure. The rigidity of the aromatic ring imparts improved mechanical properties to the PVC material, while the flexibility of the long-chain fatty acid ester imparts good toughness to the material. Furthermore, the plant oil-based PVC plasticizer of the present invention has polar functional groups within its structure, which enhance hydrogen bonding with the PVC chain and thus inhibit plasticizer migration. Experiments have shown that the plant oil-based PVC plasticizer combines plasticizing properties, heat-resistant stability, and low migration, exhibiting excellent compatibility with PVC materials and significantly improving the rigidity, elongation at break, and high-temperature stability of PVC materials.

[0015] According to a second aspect of the present invention, there is provided a method for preparing a vegetable oil-based PVC plasticizer, comprising the following steps:

[0016] (1) subjecting vegetable oil to saponification reaction with a 95% ethanol solution containing sodium hydroxide to obtain a mixed solution, removing unsaponifiable matter from the mixed solution, adjusting the pH value to 3-4 with phosphoric acid, and then separating and purifying the mixed solution. The purified product is dried and the solvent is removed to obtain vegetable oleic acid;

[0017] (2) dissolving vegetable oleic acid, a compound having an aromatic ring and a phenolic hydroxyl group, and N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (TCFH) in a first organic solvent, then adding a basic catalyst dropwise to react, and separating and purifying the reaction product to obtain a first reaction product;

[0018] (3) dissolving the first reaction product in a second organic solvent, and then sequentially adding an epoxidizing agent and a sodium carbonate solution to form a two-phase system; the first reaction product and the epoxidizing agent undergo an epoxidation reaction in the two-phase system, separating the organic phase after the reaction, and separating and purifying the reaction product in the organic phase to obtain;

[0019] Among them, the compound having an aromatic ring and a phenolic hydroxyl group is phloroglucinol, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol, 2,4,6-tris(4-hydroxyphenyl)-s-triazine or 4,4',4''-tricyclo[3.3.1.1 3.7 ]Decane-1,3,5-triyltriphenol; the vegetable oil is soybean oil, linseed oil or palm oil.

[0020] This invention discloses a method for preparing a plant oil-based PVC plasticizer. First, using inexpensive plant oil as a raw material, the method utilizes the easily cleavable nature of triglycerides in plant oil to saponify the plant oil with sodium hydroxide to produce plant oil acid. This method addresses the high cost of improving the performance of plant oil-based plasticizers in existing methods. The plant oil acid is then esterified with a compound containing an aromatic ring and a phenolic hydroxyl group to introduce a rigid aromatic ring core, replacing the original glycerol backbone of the plant oil. This method retains the existing flexible fatty acid long chain, directly synthesizing a plant oil derivative (first reaction product) with a rigid-flexible structure in situ. Polar functional groups (epoxy and ester groups) are further introduced through an epoxidation reaction to increase the polarity of the plant oil-based PVC plasticizer. Ultimately, a plasticizer molecule with a core-shell structure is constructed. This simple preparation method enhances hydrogen bonding between the plant oil-based PVC plasticizer and the PVC chain.

[0021] In some embodiments, in step (1), the temperature of the saponification reaction is 65-75°C.

[0022] In some embodiments, in step (2), the temperature for the reaction of adding the alkaline catalyst dropwise is room temperature.

[0023] In some embodiments, in step (3), the temperature of the epoxidation reaction is room temperature.

[0024] In some embodiments, in step (1), the molar ratio of vegetable oil to sodium hydroxide is (0.07-0.1):1.

[0025] In some embodiments, in step (2), the molar ratio of the compound having an aromatic ring and a phenolic hydroxyl group, vegetable oleic acid, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate, and the alkaline catalyst is 1:(4.0-6.0):(10.0-15.0):(9.0-12.0). Preferably, the molar ratio of the compound having an aromatic ring and a phenolic hydroxyl group, vegetable oleic acid, N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate, and the alkaline catalyst is 1:5.0:10.0:10.0.

[0026] In some embodiments, the basic catalyst is selected from at least one of pyridine and N-methylimidazole.

[0027] In some embodiments, the first organic solvent is acetonitrile, and the second organic solvent is selected from at least one of dichloromethane and chloroform.

[0028] In some embodiments, the epoxidizing agent is meta-chloroperbenzoic acid (m-CPBA).

[0029] In some embodiments, the molar ratio of the epoxidant to the vegetable oleic acid is (3.5-5.5): 1. Preferably, the molar ratio of the epoxidant to the vegetable oleic acid is 4.0:1.

[0030] In some embodiments, the method for preparing a vegetable oil-based PVC plasticizer comprises the following steps:

[0031] (1) Saponifying the vegetable oil with a 95% ethanol solution containing sodium hydroxide to obtain a mixture, then diluting the mixture with distilled water, extracting the unsaponified matter in the mixture with ethyl acetate, adjusting the pH value to 3-4 with phosphoric acid, filtering and washing the filtrate with water until neutral, drying the product over anhydrous sodium sulfate, and finally removing the solvent by rotary evaporation to obtain vegetable oleic acid;

[0032] (2) dissolving vegetable oleic acid, a compound having an aromatic ring and a phenolic hydroxyl group, and N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate in a first organic solvent, and adding a basic catalyst dropwise to the first organic solvent to obtain a reaction mixture; stirring the reaction mixture overnight, then diluting the reaction mixture with ethyl acetate and pouring the diluted reaction mixture into a saturated sodium bicarbonate solution, collecting the organic layer by separation, and then drying over anhydrous sodium sulfate and concentrating under reduced pressure to obtain a crude product, and subjecting the crude product to silica gel column chromatography to obtain a first reaction product;

[0033] (3) The first reaction product is dissolved in dichloromethane, an epoxidizing agent is first added to the dichloromethane, and then a sodium carbonate solution is added to the dichloromethane to form a two-phase system; the two-phase system is stirred overnight to allow the first reaction product and the epoxidizing agent to undergo an epoxidation reaction in the two-phase system, and a second organic phase is separated; the second organic phase is then washed with saturated sodium thiosulfate and sodium bicarbonate solutions in sequence, dried over anhydrous magnesium sulfate, and then filtered through a short column of basic alumina to obtain the product.

[0034] In some embodiments, the eluent used for silica gel column chromatography consists of n-hexane and ethyl acetate, and the volume ratio of n-hexane to ethyl acetate is 100:2.

[0035] According to a third aspect of the present invention, there is provided an application of a plant oil-based PVC plasticizer, particularly in the preparation of PVC materials.

[0036] After the vegetable oil-based PVC plasticizer of the present invention is blended with PVC, the plasticity, mechanical strength and heat stability of the PVC material are significantly improved. In vitro cytotoxicity test results show that the plasticizer is non-toxic to L929 cells.

[0037] In some embodiments, the PVC material is a food packaging material, a medical and sanitary product, or a children's toy.

[0038] In some embodiments, when the PVC material is a PVC film, the PVC film is prepared by dissolving the PVC in an organic solvent, adding a vegetable oil-based PVC plasticizer, stirring, and then drying to remove the organic solvent. Specifically, the organic solvent is tetrahydrofuran (THF).

[0039] In some embodiments, the amount of the vegetable oil-based PVC plasticizer used is 20% to 35% of the mass of the PVC film. Preferably, the amount of the vegetable oil-based PVC plasticizer used is 30% of the mass of the PVC film.

[0040] In some embodiments, the mass concentration of PVC in tetrahydrofuran is 4.5-5.5 g / mL. Preferably, the mass concentration of PVC in tetrahydrofuran is 5.0 g / mL.

[0041] The beneficial effects of the present invention are:

[0042] (1) The plant oil-based PVC plasticizer of the present invention has a "rigid core-flexible arm" molecular structure, with a rigid aromatic ring structure and a long fatty acid ester chain, which can solve the defect of traditional plant oil-based plasticizers in insufficiently improving the mechanical strength of PVC products; and has polar functional groups, which can enhance the hydrogen bonding effect with the PVC chain, and has good compatibility with PVC, which can inhibit the migration of the plasticizer;

[0043] (2) The vegetable oil-based PVC plasticizer of the present invention introduces a rigid aromatic ring core into the vegetable oil through a one-step catalytic esterification process to replace the glycerol skeleton of the vegetable oil, retaining the flexible fatty acid long chain of the vegetable oil, and directly synthesizing the vegetable oil derivative with a rigid-flexible junction in situ, and the preparation method is simple;

[0044] (3) The plant oil-based PVC plasticizer provided by the present invention is non-toxic and environmentally friendly, has good high temperature resistance, and has excellent plasticizing performance on PVC materials, and has a very broad application prospect in the preparation of PVC materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The synthetic route of the vegetable oil-based PVC plasticizer of the present invention is as follows;

[0046] Figure 2 This is the H NMR spectrum of SFA of Example 1 of the present invention;

[0047] Figure 3 is the H NMR spectrum of SFAP of Example 1 of the present invention;

[0048] Figure 4 This is the H NMR spectrum of EPO-SFAP of Example 1 of the present invention;

[0049] Figure 5 This is the H NMR spectrum of SFATB of Example 2 of the present invention;

[0050] Figure 6 This is the H NMR spectrum of EPO-SFATB of Example 2 of the present invention;

[0051] Figure 7 This is the H NMR spectrum of SFATT of Example 3 of the present invention;

[0052] Figure 8 This is the H NMR spectrum of EPO-SFATT of Example 3 of the present invention;

[0053] Figure 9 This is the H NMR spectrum of SFATA of Example 4 of the present invention;

[0054] Figure 10 This is the H NMR spectrum of EPO-SFATA of Example 4 of the present invention;

[0055] Figure 11 The stress-strain curves of the PVC films prepared in Application Example 1, Application Example 2 and Comparative Example 1 of the present invention are shown;

[0056] Figure 12 The glass transition temperature test results of the PVC films prepared in Application Example 1, Application Example 2 and Comparative Example 1 of the present invention are shown;

[0057] Figure 13 These are the test results of high temperature resistance and thermal stability of the PVC films prepared in Application Example 1, Application Example 2 and Comparative Example 1 of the present invention.

[0058] Figure 14 These are the cytotoxicity test results of ESO, EPO-SFAP and EPO-SFATB of the present invention. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the accompanying drawings, but the embodiments of the present invention are not limited thereto. The raw materials and reagents involved in the following examples can all be obtained from commercial channels.

[0060] Figure 1The synthesis pathway of the plant oil-based PVC plasticizer of the present invention is demonstrated. Soybean oil is saponified and hydrolyzed to produce soy oleic acid. Then, in the presence of N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate (TCFH) and pyridine (Pyr), a compound containing an aromatic ring and phenolic hydroxyl groups is esterified with the soy oleic acid to produce a colorless oil with a rigid benzene ring structure and a flexible long-chain fatty acid ester. Finally, the double bond of the long-chain fatty acid ester is epoxidized with m-chloroperbenzoic acid (m-CPBA) to produce the plant oil-based PVC plasticizer of the present invention. The plant oil-based PVC plasticizer of the present invention has a "rigid core-flexible arm" molecular structure. Chemically, the rigid aromatic ring core with varying conjugation strength and electron cloud density is introduced to replace the original glycerol backbone of the plant oil, while retaining the existing flexible fatty acid long chains. This allows for the direct in situ synthesis of a plant oil derivative with a rigid-flexible structure, and further increases its polarity through epoxidation.

[0061] It should be noted that the above is only one embodiment of the present invention. Soybean oil can be replaced by vegetable oils with double bonds and ester structures, such as linseed oil and palm oil. Compounds with aromatic rings and phenolic hydroxyl groups can be selected from phloroglucinol, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol, 2,4,6-tris(4-hydroxyphenyl)-s-triazine, 4,4',4''-tricyclo[3.3.1.1 3.7 ]Decane-1,3,5-triyltriphenol.

[0062] Phloroglucinol, 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol, 2,4,6-tris(4-hydroxyphenyl)-s-triazine (2,4,6-tris(4-hydroxyphenyl)-1,3,5-triazine), 4,4',4''-tricyclo[3.3.1.1 3.7 The structural formula of decane-1,3,5-triyltriphenol is shown below:

[0063] .

[0064] The structural formulas of soybean oil, linseed oil and palm oil used in the present invention are shown below:

[0065] .

[0066] Example 1

[0067] This embodiment provides a plant oil-based PVC plasticizer, which is prepared by the following method:

[0068] (1) 100 g of soybean oil was mixed with 600 mL of 95% ethanol solution containing 58.91 g of sodium hydroxide (1.47 mol) and reacted at 70°C for 2 h for saponification. After the reaction was completed, 400 mL of distilled water was added for dilution and unsaponifiable matter was removed by extraction with 500 mL of ethyl acetate. The extracted aqueous phase was adjusted to pH 3 with phosphoric acid, filtered, washed with water until neutral, dried over anhydrous sodium sulfate, and finally evaporated to remove the solvent to obtain soybean oleic acid product SFA as a light yellow oil.

[0069] (2) 10.0 g of phloroglucinol, 125.1 g of soybean oleic acid product SFA, and 328.7 g of TCFH were dissolved in acetonitrile, and 62.5 g of pyridine was slowly added dropwise to obtain a reaction mixture. The reaction mixture was then stirred at room temperature overnight, diluted with ethyl acetate, and the diluted reaction mixture was poured into a saturated aqueous sodium bicarbonate solution. The yellow organic layer was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: n-hexane / ethyl acetate = 100:2) to obtain SFAP (35.6 g, calculated yield 45%) as a colorless oil.

[0070] (3) The colorless oil was dissolved in dichloromethane, and then m-chloroperbenzoic acid (m-CPBA) (24.5 g) was added in portions. A sodium carbonate aqueous solution was added to the solution to form a two-phase system. After stirring at room temperature overnight, the organic phase was separated and washed with saturated sodium thiosulfate and sodium bicarbonate solutions in sequence. After drying over anhydrous magnesium sulfate and filtering through a short column of basic alumina, the colorless liquid product EPO-SFAP was finally obtained.

[0071] The soybean oleic acid product SFA, colorless oil SFAP and colorless liquid product EPO-SFAP were characterized by nuclear magnetic resonance hydrogen spectrum. The characterization results are as follows: Figures 2-4 As shown. Figure 3 Medium δ H 6.81 (3H, s, Ar-H), 5.43-5.29 (9H, m, CH2=CH2) confirmed that three soybean oleic acid chains were successfully grafted onto phloroglucinol. Figure 4 Medium δ H 6.79 (3H, s, Ar-H), 3.20-2.83 (9H, m, CH-O-CH), confirming the successful epoxidation of EPO-SFAP. These results demonstrate the successful synthesis of the soybean oil acid product SFA through esterification with phloroglucinol. The above preparation method can be used to successfully isolate and obtain a colorless oily substance, SFAP. The carbon-carbon double bond of the colorless oily substance SFAP was then epoxidized with m-CPBA to form EPO-SFAP, demonstrating the successful synthesis of a plant oil-based PVC plasticizer.

[0072] Example 2

[0073] This embodiment provides a vegetable oil-based PVC plasticizer, which is prepared by the following method:

[0074] (1) 100 g of soybean oil was mixed with 600 mL of 95% ethanol solution containing 58.91 g of sodium hydroxide (1.47 mol) and reacted at 70°C for 2 h for saponification. After the reaction was completed, 400 mL of distilled water was added for dilution and unsaponifiable matter was removed by extraction with 500 mL of ethyl acetate. The aqueous phase was adjusted to pH 3 with phosphoric acid, filtered, washed with water until neutral, dried over anhydrous sodium sulfate, and finally evaporated to remove the solvent to obtain soybean oleic acid (SFA) as a light yellow oil.

[0075] (2) 28.0 g of 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol, 125.1 g of soybean oleic acid product SFA, and 328.7 g of TCFH were dissolved in acetonitrile, and 62.5 g of pyridine was slowly added dropwise to obtain a reaction mixture. The reaction mixture was stirred at room temperature overnight, then diluted with ethyl acetate and the diluted reaction mixture was poured into a saturated aqueous sodium bicarbonate solution. The yellow organic layer was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: n-hexane / ethyl acetate = 100:2) to obtain SFATB as a colorless oil.

[0076] (3) The colorless oily product SFATB was dissolved in dichloromethane, and then m-chloroperbenzoic acid (m-CPBA) (24.5 g) was added in portions. A sodium carbonate aqueous solution was added to the solution to form a two-phase system. After stirring and reacting at room temperature overnight, the organic phase was separated and washed with saturated sodium thiosulfate and sodium bicarbonate solutions in sequence. After drying over anhydrous magnesium sulfate and filtering through a short column of basic alumina, the colorless liquid product EPO-SFATB was finally obtained.

[0077] The colorless oily product SFATB and the colorless liquid product EPO-SFATB were characterized by nuclear magnetic resonance hydrogen spectrum. The characterization results are as follows Figure 5 and Figure 6 As shown. Figure 5 Medium δ H 7.73 (3H, s, Ar-H), 7.71- 7.66 (6H, m, Ar-H), 7.24-7.19 (6H, m, Ar-H), 5.45-5.32 (9H, m, CH2=CH2) confirmed that three soybean oleic acid chains were successfully grafted onto 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol. Figure 6 Medium δ HThe δ values ​​of 7.71 (3H, s, Ar-H), 7.68-7.64 (6H,m, Ar-H), 7.21-7.18 (6H, m, Ar-H), and 3.15-2.84 (9H, m, CH-O-CH) confirmed that EPO-SFATB was successfully obtained through epoxidation. These results indicate that the soybean oleic acid product SFA was successfully synthesized through esterification with 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol. The colorless oil SFATB was successfully isolated and isolated using the above preparation method. The carbon-carbon double bond of the colorless oil SFATB was then successfully introduced into an epoxy group through epoxidation using m-CPBA to obtain EPO-SFATB, indicating that this plant oil-based PVC plasticizer was successfully synthesized.

[0078] Example 3

[0079] This embodiment provides a plant oil-based PVC plasticizer, which is prepared by the following method:

[0080] (1) 100 g of soybean oil was mixed with 600 mL of 95% ethanol solution containing 58.91 g of sodium hydroxide (1.47 mol) and reacted at 70°C for 2 h for saponification. After the reaction was completed, 400 mL of distilled water was added for dilution and unsaponifiable matter was removed by extraction with 500 mL of ethyl acetate. The aqueous phase was adjusted to pH 3 with phosphoric acid, filtered, washed with water until neutral, dried over anhydrous sodium sulfate, and finally evaporated to remove the solvent to obtain soybean oleic acid (SFA) as a light yellow oil.

[0081] (2) 28.2 g of 2,4,6-tris(4-hydroxyphenyl)-s-triazine, 125.1 g of soybean oleic acid product SFA, and 328.7 g of TCFH were dissolved in acetonitrile, and 62.5 g of pyridine was slowly added dropwise to obtain a reaction mixture. The reaction mixture was stirred at room temperature overnight, then diluted with ethyl acetate and the diluted reaction mixture was poured into a saturated sodium bicarbonate aqueous solution. The yellow organic layer was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: n-hexane / ethyl acetate = 100:2) to obtain SFATT as a colorless oil.

[0082] (3) The colorless oily product SFATT was dissolved in dichloromethane, and then m-chloroperbenzoic acid (m-CPBA) (24.5 g) was added in portions. A sodium carbonate aqueous solution was added to the solution to form a two-phase system. After stirring and reacting at room temperature overnight, the organic phase was separated and washed with saturated sodium thiosulfate and sodium bicarbonate solutions in sequence. After drying over anhydrous magnesium sulfate and filtering through a short column of basic alumina, the colorless liquid product EPO-SFATT was finally obtained.

[0083] The colorless oily product SFATT and the colorless liquid product EPO-SFATT were characterized by nuclear magnetic resonance hydrogen spectrum. The characterization results are as follows Figure 7 and Figure 8 As shown. Figure 7 Medium δ H 8.80-8.73 (6H, m, Ar-H), 7.32-7.25 (6H, m, Ar-H), 5.37 (9H, m, CH2=CH2) confirmed that three soybean oleic acid chains were successfully grafted on 2,4,6-tris(4-hydroxyphenyl)-s-triazine. Figure 8 Medium δ H 8.77 (6H, m, Ar-H), 7.32- 7.26 (6H, m, Ar-H), 3.17-2.85 (9H, m, CH-O-CH), confirming the successful epoxidation to EPO-SFATT. These results indicate that the soybean oleic acid product SFA was successfully synthesized through esterification with 2,4,6-tris(4-hydroxyphenyl)-s-triazine. The above preparation method can be successfully isolated to obtain a colorless oily substance SFATT. The carbon-carbon double bond of the colorless oil SFATT was then successfully introduced into an epoxy group through epoxidation using m-CPBA to obtain EPO-SFATT, indicating the successful synthesis of this plant oil-based PVC plasticizer.

[0084] Example 4

[0085] This embodiment provides a vegetable oil-based PVC plasticizer, which is prepared by the following method:

[0086] (1) 100 g of soybean oil was mixed with 600 mL of 95% ethanol solution containing 58.91 g of sodium hydroxide (1.47 mol) and reacted at 70°C for 2 h for saponification. After the reaction was completed, 400 mL of distilled water was added for dilution and unsaponifiable matter was removed by extraction with 500 mL of ethyl acetate. The aqueous phase was adjusted to pH 3 with phosphoric acid, filtered, washed with water until neutral, dried over anhydrous sodium sulfate, and finally evaporated to remove the solvent to obtain soybean oleic acid (SFA) as a light yellow oil.

[0087] (2) 38.9 g of 4,4',4''-tricyclic [3.3.1.1 3.7 Decane-1,3,5-triyltriphenol, 125.1 g of soybean oleic acid product SFA, and 328.7 g of TCFH were dissolved in acetonitrile, and 62.5 g of pyridine was slowly added dropwise to obtain a reaction mixture. The reaction mixture was stirred at room temperature overnight, then diluted with ethyl acetate and poured into a saturated aqueous sodium bicarbonate solution. The yellow organic layer was collected, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (eluent: n-hexane / ethyl acetate = 100:2) to obtain SFATA as a colorless oil.

[0088] (3) The colorless oily substance SFATA was dissolved in dichloromethane, and then m-chloroperbenzoic acid (m-CPBA) (24.5 g) was added in portions. A sodium carbonate aqueous solution was added to the solution to form a two-phase system. After stirring and reacting at room temperature overnight, the organic phase was separated and washed with saturated sodium thiosulfate and sodium bicarbonate solutions in sequence. After drying over anhydrous magnesium sulfate and filtering through a short column of basic alumina, the colorless liquid product EPO-SFATA was finally obtained.

[0089] The colorless oily substance SFATA and the colorless liquid product EPO-SFATA were characterized by nuclear magnetic resonance hydrogen spectrum. The characterization results are as follows Figure 9 and Figure 10 As shown. Figure 9 Medium δ H 7.43-7.37 (6H, m, Ar-H), 7.07-7.01 (6H, m, Ar-H), 5.43-5.28 (9H, m, CH2=CH2) confirmed that the three soybean oleic acid chains were in 4,4',4''-tricyclo[3.3.1.1 3.7 ]Decane-1,3,5-triyltriphenol grafting was successful. Figure 10 Medium δ H 7.44-7.34 (6H, m, Ar-H), 7.10-7.01 (6H, m, Ar-H), 3.26-2.84 (9H, m, CH-O-CH), confirming the successful epoxidation to obtain EPO-SFATA. These results indicate that the soybean oleic acid product SFA was successfully synthesized through esterification with 2,4,6-tris(4-hydroxyphenyl)-s-triazine. The above preparation method can be successfully used to isolate and obtain a colorless oily substance SFATA. The carbon-carbon double bond of the colorless oily SFATA was then successfully introduced into an epoxy group through epoxidation using m-CPBA to obtain EPO-SFATA, indicating the successful synthesis of this plant oil-based PVC plasticizer.

[0090] Application Example 1

[0091] This application example provides the application of a vegetable oil-based PVC plasticizer in the preparation of a PVC film, including the following steps:

[0092] 1.4 g of PVC was dissolved in THF to obtain a mixed solution with a PVC concentration of 5.0 g / mL. 0.6 g of the vegetable oil-based PVC plasticizer EPO-SFAP prepared in Example 1 was added. The mixture was then vigorously stirred at room temperature for 2 hours until the solids were completely dissolved, forming a homogeneous, transparent solution. The solution was transferred to a 6 cm diameter Petri dish and placed in a vacuum oven for 3 days to remove the THF. Subsequently, the Petri dish was placed in an oven at 50°C for 1 day to ensure complete removal of any residual THF. This yielded a PVC film, designated PVC-EPO-SFAP.

[0093] Application Example 2

[0094] This application example provides the application of a vegetable oil-based PVC plasticizer in the preparation of a PVC film, including the following steps:

[0095] 1.4 g of PVC was dissolved in THF to obtain a mixed solution with a PVC concentration of 5.0 g / mL. 0.6 g of the vegetable oil-based PVC plasticizer EPO-SFATB (30%) prepared in Example 2 was added. The mixture was then vigorously stirred at room temperature for 2 hours until the solids were completely dissolved, forming a homogeneous, transparent solution. The solution was transferred to a 6 cm diameter Petri dish and placed in a vacuum oven for 3 days to remove the THF. Subsequently, the Petri dish was placed in a 50°C oven for 1 day to ensure complete removal of any residual THF. This yielded a PVC film, designated PVC-EPO-SFATB.

[0096] Comparative Example 1

[0097] This comparative example uses epoxy soybean oil as a PVC plasticizer to prepare a PVC film, comprising the following steps:

[0098] 1.4 g of PVC was dissolved in THF, and 0.6 g of epoxidized soybean oil was added. The mixture was then vigorously stirred at room temperature for 2 hours until the solids were completely dissolved, forming a homogeneous, transparent solution. The solution was transferred to a 6 cm diameter Petri dish and placed in a vacuum oven for 3 days to remove the THF. Subsequently, the Petri dish was placed in an oven at 50°C for 1 day to ensure complete removal of any residual THF. This resulted in a PVC film, designated PVC-ESO.

[0099] In order to compare the effects of the vegetable oil-based PVC plasticizers prepared in Examples 1-2 on the comprehensive properties of PVC films relative to those of epoxidized soybean oil, the PVC films prepared in Application Example 1, Application Example 2 and Comparative Example 1 were tested through Experimental Examples 1-3.

[0100] Experimental Example 1

[0101] In this experimental example, mechanical properties tests were performed on the PVC-EPO-SFAP prepared in Example 1, the PVC-EPO-SFATB prepared in Application Example 2, and the PVC-ESO prepared in Comparative Example 1 (hereinafter referred to as "samples").

[0102] The mechanical properties of the films were characterized using an electronic universal testing machine (E44) in accordance with GB / T 104.1-2006. Test conditions: Tensile strength and elongation at break were measured at 25°C and a tensile rate of 20 mm / min. Sample dimensions were 30 mm × 10 mm (length × width). Five sets of data were collected, and the average values ​​were calculated and recorded. The test results for tensile strength, elongation at break, and toughness are shown in Table 1. The stress-strain curves for each PVC film are shown in Table 1. Figure 11 .

[0103] Table 1 Mechanical properties test results

[0104]

[0105] From Table 1 and Figure 11 It can be seen that the tensile strength, elongation at break, and toughness of PVC-EPO-SFAP and PVC-EPO-SFATB are significantly improved compared to PVC-ESO, with PVC-EPO-SFATB having the highest tensile strength, elongation at break, and toughness. This is because PVC-EPO-SFATB has more benzene rings and denser π-π stacking, which limits the thermal motion of the PVC molecular chain and improves the material's toughness. The above results show that compared to epoxy soybean oil as a plasticizer, the plant oil-based PVC plasticizer of the present invention has a good plasticizing effect on PVC film, specifically manifested in that the plant oil-based PVC plasticizer can significantly improve the mechanical properties of PVC composite materials, showing a trend of enhancing and toughening the mechanical properties of PVC film.

[0106] Experimental Example 2

[0107] In this experimental example, the glass transition temperature of PVC-EPO-SFAP prepared in Example 1, PVC-EPO-SFATB prepared in Application Example 2, and PVC-ESO prepared in Comparative Example 1 (hereinafter referred to as "samples") were tested.

[0108] The T values ​​of the samples were characterized using a dynamic mechanical analyzer (Netzsch DMA 242E). g For testing, the sample was cut into strips measuring 20 mm × 5 mm × 0.4 mm (length × width × thickness). Testing procedure: The temperature was lowered to -50°C using liquid nitrogen and then heated to 65°C at a rate of 5°C / min. The tensile frequency was 1 Hz.

[0109] The test results of glass transition temperature of each PVC film are shown in Figure 12 .Depend on Figure 12 The glass transition temperature T of each sample was obtained g , as shown in Table 2.

[0110] Table 2 Glass transition temperature

[0111]

[0112] from Figure 12 It can be seen that each PVC film shows only one symmetrical peak, indicating that PVC has good compatibility with plant oil-based PVC plasticizer. As can be seen from Table 2, the T g Both are higher than PVC-ESO, indicating that the vegetable oil-based PVC plasticizer of the present invention can increase the glass transition temperature of the PVC film compared with epoxy soybean oil.

[0113] Experimental Example 3

[0114] In this experimental example, the high temperature stability performance test was performed on the PVC-EPO-SFAP prepared in Example 1, the PVC-EPO-SFATB prepared in Application Example 2, and the PVC-ESO prepared in Comparative Example 1 (hereinafter referred to as "samples").

[0115] During testing, the sample was cut into strips measuring 25 mm × 25 mm × 0.4 mm (length × width × thickness). Testing Procedure: The sample was placed in a 180°C vacuum oven, and the film's color change was observed by video and photography every 10 minutes.

[0116] The color changes of each PVC film are as follows Figure 13 As shown. Figure 13 It can be seen that PVC-ESO turns yellow at 10 min, gradually turns red at 20 min, and completely turns black at 140 min. PVC-EPO-SFAP gradually turns red at 110 min, and eventually remains reddish brown until 3 h, while PVC-EPO-SFATB remains light yellow until 3 h. The above results show that the vegetable oil-based PVC plasticizer synthesized by the present invention can significantly improve the high-temperature stability of PVC film. Among them, PVC-EPO-SFATB has the best effect on improving the high-temperature stability of PVC film. This is because the huge volume and rigidity of the benzene ring structure in 2,4,6-tris(4-hydroxyphenyl)-1,3,5-triyltriphenol significantly limit the thermal motion of the PVC molecular chain, resulting in limited molecular chain motion, thereby improving its high-temperature resistance.

[0117] Experimental Example 4

[0118] In this experimental example, in vitro cytotoxicity experiments were conducted on the EPO-SFAP prepared in Example 1, the EPO-SFATB prepared in Example 2, and ESO (hereinafter referred to as "samples").

[0119] In vitro cytotoxicity assays were performed on the samples using mouse fibroblasts (L929). Live / dead cell staining was used to determine cell viability and evaluate the biocompatibility of the plasticizers.

[0120] L929 cells were seeded into 96-well plates and cultured overnight for 24 h. Then, 100 μL of samples diluted in DMEM medium / serum (at concentrations of 10, 5, 1, 0.2, 0.1, and 0.05 mg ml) were added. -1 ) and incubate for 24 hours. Then, 10 µL of MTT solution (5 mg / mL) was added to each well and incubated for 4 hours. After discarding the spent culture medium and MTT solution, 150 µL of DMSO was added to each well to completely dissolve the formazan crystals. The results were measured in a microplate reader at a wavelength of 490 nm.

[0121] Cell viability results are shown in Figure 14 .Depend on Figure 14 It can be seen that the cell survival rate of L929 cells treated with samples of different concentrations after culture was higher than 100%, indicating that the proliferation of L929 cells cultured after EPO-SFAP, EPO-SFATB and ESO exceeded the initial number. Among them, different concentrations of samples had different effects on the proliferation of L929 cells. Specifically, when the sample concentration was 0.1 mg ml -1 When the sample concentration was 10 and 0.05 mg ml -1 When the sample concentration was 5, 1, and 0.2 mg ml -1 At 400 μg / mL, the cell survival rate of L929 cells treated with EPO-SFAP was significantly higher than that of L929 cells treated with ESO, indicating that at this concentration, EPO-SFAP is more conducive to the proliferation of L929 cells. The above results show that the vegetable oil-based PVC plasticizer of the present invention is a non-toxic bio-based PVC plasticizer.

[0122] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the inventive concept of the present invention, which all fall within the scope of protection of the present invention.

Claims

1. A method for preparing a vegetable oil-based PVC plasticizer, characterized in that: The following steps are involved: (1) subjecting vegetable oil to saponification reaction with a 95% ethanol solution containing sodium hydroxide to obtain a mixed solution, removing unsaponifiable matter from the mixed solution, adjusting the pH value to 3-4 with phosphoric acid, and then separating and purifying the mixed solution, drying the product, and removing the solvent to obtain vegetable oleic acid; (2) dissolving vegetable oleic acid, a compound having an aromatic ring and a phenolic hydroxyl group, and N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate in a first organic solvent, then adding a basic catalyst dropwise to react, and separating and purifying the reaction product to obtain a first reaction product; (3) dissolving the first reaction product in a second organic solvent, and then sequentially adding an epoxidizing agent and a sodium carbonate solution to obtain a two-phase system; the first reaction product and the epoxidizing agent undergo an epoxidation reaction in the two-phase system, separating the organic phase after the reaction, and separating and purifying the reaction product in the organic phase to obtain; The compound having an aromatic ring and a phenolic hydroxyl group is phloroglucinol, or 2,4,6-tris(4-hydroxyphenyl)-s-triazine; The vegetable oil is soybean oil, linseed oil or palm oil; In step (1), the molar ratio of the vegetable oil to the sodium hydroxide is (0.07-0.1):1; in step (2), the molar ratio of the compound having an aromatic ring and a phenolic hydroxyl group, the vegetable oil acid, the N,N,N',N'-tetramethylchloroformamidine hexafluorophosphate, and the alkaline catalyst is 1:(4.0-6.0):(10.0-15.0):(9.0-12.0); The molar ratio of the epoxidant to the vegetable oleic acid is (3.5-5.5):

1.

2. The method for preparing a vegetable oil-based PVC plasticizer according to claim 1, wherein The epoxidizing agent is m-chloroperbenzoic acid.

3. The method for preparing a vegetable oil-based PVC plasticizer according to claim 1 or 2, wherein: In step (1), the temperature of the saponification reaction is 65-75°C; In step (2), the temperature for the reaction of adding the alkaline catalyst dropwise is room temperature; In step (3), the temperature of the epoxidation reaction is room temperature.

4. The method for preparing a vegetable oil-based PVC plasticizer according to claim 3, wherein: The first organic solvent is acetonitrile, the second organic solvent is selected from at least one of dichloromethane and chloroform; and the alkaline catalyst is selected from at least one of pyridine and N-methylimidazole.

5. The vegetable oil-based PVC plasticizer prepared by the preparation method of the vegetable oil-based PVC plasticizer according to any one of claims 1 to 4.

6. The use of the vegetable oil-based PVC plasticizer according to claim 5, characterized in that: The application is the application of plant oil-based PVC plasticizer in the preparation of PVC materials.

7. The use of the vegetable oil-based PVC plasticizer according to claim 6, characterized in that: The PVC material is food packaging material, medical and sanitary products or children's toys.

8. The use of the vegetable oil-based PVC plasticizer according to claim 6 or 7, characterized in that: When the PVC material is a PVC film, it is prepared by the following steps: dissolving PVC in an organic solvent, adding a vegetable oil-based PVC plasticizer, stirring, and drying to remove the organic solvent.

9. The use of the vegetable oil-based PVC plasticizer according to claim 8, characterized in that: The amount of the vegetable oil-based PVC plasticizer used is 20% to 35% of the mass of the PVC film.

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