Bio-based plasticizer as well as preparation method and application thereof
By developing a method for preparing bio-based plasticizers, the toxicity and migration issues of petroleum-based phthalate plasticizers have been resolved, improving the flexibility and optical properties of polyvinyl chloride products and enabling the application of environmentally friendly plasticizers.
Patent Information
- Application Number
- CN202511632875.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-10
- Publication Date
- 2026-03-20
AI Technical Summary
Existing petroleum-based phthalate plasticizers have toxicity and migration issues, affecting health and the environment, and are unsuitable for use in fields such as medical devices and food packaging.
A bio-based plasticizer preparation method is adopted, in which vanillic acid reacts with lactic acid to generate vanillic acid lactate, which then reacts with n-heptanol and isobutyric anhydride to form a bio-based plasticizer, thereby increasing the ratio of polar and non-polar groups and improving plasticizing performance and migration resistance.
Bio-based plasticizers improve the flexibility and optical properties of PVC products, reduce the risk of plasticizer migration, and are simple and environmentally friendly to process, solving the toxicity and migration problems of traditional plasticizers.
Smart Images
Figure CN121698754A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of plasticizer technology, specifically to a bio-based plasticizer, its preparation method, and its application. Background Technology
[0002] Polyvinyl chloride (PVC), along with polyethylene (PE), polypropylene (PP), polystyrene (PS), and acrylonitrile-butadiene-styrene copolymer (ABS), is known as one of the five major plastics and plays a vital role in industrial applications. Flexible PVC is widely used in medical devices, children's toys, and food packaging, where high safety requirements apply. The dipoles of the C-Cl bonds in PVC molecules lead to interactions between chains, restricting chain mobility and causing brittleness. Therefore, plasticizers are widely used in molding and processing to improve the performance of PVC.
[0003] Currently, the main plasticizers used in industry are petroleum-based phthalates, with an annual output of up to 20 million tons, accounting for more than 70% of the plasticizer market. However, phthalates have a certain degree of toxicity due to the presence of benzene rings. Studies have shown that the migration of phthalates can accumulate in the human body, interfering with the endocrine system and causing liver toxicity and teratogenicity. Many countries and regions, including the EU and the US, have restricted the use of phthalates in certain areas. Furthermore, phthalates have poor migration resistance, and their application in medical products and food packaging will inevitably harm human health and environmental safety. Related studies have also confirmed that phthalates are carcinogenic. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a bio-based plasticizer and its preparation method. By introducing oligolactic acid into the vanillic acid skeleton, abundant polar groups are obtained. At the same time, the introduction of n-heptanol expands the proportion of non-polar groups in the plasticizer, effectively improving the plasticizing performance and migration resistance of the plasticizer, and realizing the application of the bio-based plasticizer of the present invention in polyvinyl chloride products.
[0005] The technical problem to be solved by the present invention is achieved by the following technical solution: One objective of this invention is to provide a bio-based plasticizer, the structural formula of which is as follows: ; Where n is 3 to 4.
[0006] A second objective of this invention is to provide a method for preparing a bio-based plasticizer, comprising the following steps: (1) Vanillic acid is reacted with lactic acid to obtain vanillic acid lactate; (2) Vanillyl lactate was reacted with n-heptyl alcohol to obtain heptyl vanillyl lactate; (3) Heptyl vanillic acid lactate was reacted with isobutyric anhydride to obtain a bio-based plasticizer.
[0007] The reaction equation is as follows: .
[0008] Furthermore, the molar ratio of vanillic acid to lactic acid is 1:(3~4).
[0009] Furthermore, the molar ratio of vanillyl lactate to n-heptanol is 1:(1~1.2).
[0010] Furthermore, the molar ratio of heptyl vanillic acid lactate to isobutyric anhydride is 1:(1~1.2).
[0011] The esterification reaction involved in this invention can employ a water-removing agent-catalyst reaction system commonly used in the art. The water-removing agent includes, but is not limited to, one or more of toluene and cyclohexane, and the catalyst includes, but is not limited to, one or more of titanium sulfate, p-toluenesulfonic acid, and stannous octoate.
[0012] A third objective of this invention is to provide a composite plasticizer, including the aforementioned bio-based plasticizer.
[0013] Furthermore, the composite plasticizer also includes one or more of the plasticizers existing in the art, such as phthalate plasticizers, aliphatic diester plasticizers, epoxy plasticizers, phosphate plasticizers, citrate plasticizers, polyol ester plasticizers, polyester plasticizers, and chlorine-containing plasticizers.
[0014] A fourth objective of this invention is to provide the application of the aforementioned bio-based plasticizer or composite plasticizer in polyvinyl chloride.
[0015] The fifth objective of this invention is to provide a polyvinyl chloride composite material, comprising polyvinyl chloride resin and the bio-based plasticizer or the composite plasticizer.
[0016] Furthermore, the polyvinyl chloride composite material also includes one or more of the following additives: fillers, dispersants, flame retardants, lubricants, stabilizers, antioxidants, and antibacterial agents.
[0017] The beneficial effects of this invention are: 1. The vanillic acid used in this invention is derived from renewable biomass resources such as olives, kiwifruit, angelica, and vanilla. It can also be prepared industrially through the oxidation of vanillin, which is derived from lignin. The sources are wide-ranging and abundant. Another bio-based plasticizer component, lactic acid, can be obtained through the fermentation of starchy crops or crop straw, effectively improving the comprehensive utilization efficiency of various agricultural waste resources. Compared with petroleum-based plasticizers, these bio-based raw materials are not only environmentally friendly and do not harm ecosystems or human health, but also alleviate the current problem of increasingly scarce petroleum resources.
[0018] 2. The bio-based plasticizer of this invention has an oligolactic acid structure and a rigid benzene ring structure. These polar groups greatly weaken the molecular entanglement forces between polyvinyl chloride (PVC) chains, lower the glass transition temperature of plastic products, and thus significantly improve the flexibility of PVC products. Furthermore, the interaction between the abundant polar groups in the bio-based plasticizer and the polar carbon-chlorine bonds of PVC effectively prevents the migration of plasticizer molecules to the surface of the product, showing a significant improvement compared to the high migration behavior of phthalate plasticizers.
[0019] 3. Polyvinyl chloride products plasticized with the bio-based plasticizer described in this invention exhibit good plasticizing and optical properties.
[0020] 4. The preparation method of the bio-based plasticizer described in this invention has the advantages of simple process and high safety, and avoids the problem of hydrogen chloride gas emission caused by traditional acyl chloride end-capping methods. Attached Figure Description
[0021] Figure 1 This is the mass spectrum of the bio-based plasticizer described in this invention. Detailed Implementation
[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments and illustrations.
[0023] Example 1 Vanillic acid (34 g, 0.2 mol), lactic acid (54 g, 0.6 mol), cyclohexane (20 mL), and p-toluenesulfonic acid (1.1 g, 0.006 mol) were added sequentially to a round-bottom flask equipped with a condenser and an oil-water separator. The mixture was heated to 50 °C and reacted for 30 min. The reaction temperature was then increased to 110 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with saturated sodium carbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain vanillic acid lactate.
[0024] Vanillyl lactate (24 g, 0.1 mol) and n-heptanol (14 g, 0.12 mol) were added to a round-bottom flask equipped with a condenser and an oil-water separator. 20 mL of cyclohexane and p-toluenesulfonic acid (0.6 g, 0.003 mol) were added, and the mixture was reacted at 65 °C for 30 min. The reaction temperature was then raised to 125 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with saturated sodium carbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain heptanyl vanillyl lactate.
[0025] Heptyl vanillyl lactate (34 g, 0.1 mol), isobutyric anhydride (15.8 g, 0.1 mol), and 150 mL of ethyl acetate were added to a reaction vessel, and the mixture was heated under reflux for 2 h. The reaction was then stopped. The reaction solution was washed with saturated sodium carbonate solution until alkaline, and the supernatant was washed with deionized water until neutral. Finally, the solution was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain the bio-based plasticizer.
[0026] Figure 1 This is the mass spectrum of the bio-based plasticizer described in this invention. From... Figure 1 As can be seen, the theoretical molecular ion peak of the bio-based plasticizer described in this invention is 499.21, and the actual value is also 499.21. The consistency between the theoretical and actual values indicates that this invention has successfully synthesized the bio-based plasticizer with the target structure. Furthermore, the difference between the molecular ion peaks is 72, which is due to the presence of oligolactic acid in the structure.
[0027] Example 2 Vanillic acid (34 g, 0.2 mol), lactic acid (54 g, 0.6 mol), cyclohexane (20 mL), and titanium sulfate (1.4 g, 0.004 mol) were added sequentially to a round-bottom flask equipped with a condenser and an oil-water separator. The mixture was heated to 50 °C and reacted for 30 min. The reaction temperature was then raised to 110 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with saturated sodium carbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain vanillic acid lactate.
[0028] Vanillyl lactate (24 g, 0.1 mol) and n-heptanol (12 g, 0.1 mol) were added to a round-bottom flask equipped with a condenser and an oil-water separator. 20 mL of cyclohexane and titanium sulfate (0.8 g, 0.002 mol) were added, and the mixture was reacted at 65 °C for 30 min. The reaction temperature was then raised to 125 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with saturated sodium carbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution, and the organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain heptanyl vanillyl lactate.
[0029] Heptyl vanillyl lactate (34 g, 0.1 mol), isobutyric anhydride (15.8 g, 0.1 mol), and 150 mL of ethyl acetate were added to a reaction vessel, and the mixture was heated under reflux for 2 h. The reaction was then stopped. The reaction solution was washed with saturated sodium carbonate solution until alkaline, and the supernatant was washed with deionized water until neutral. Finally, the solution was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain the bio-based plasticizer.
[0030] Example 3 Vanillic acid (34 g, 0.2 mol), lactic acid (72 g, 0.8 mol), cyclohexane (20 mL), and p-toluenesulfonic acid (1.1 g, 0.006 mol) were added sequentially to a round-bottom flask equipped with a condenser and an oil-water separator. The mixture was heated to 50 °C and reacted for 30 min. The reaction temperature was then increased to 110 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with 10% sodium bicarbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution, and the organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain vanillic acid lactate.
[0031] Vanillyl lactate (24 g, 0.1 mol) and n-heptanol (14 g, 0.12 mol) were added to a round-bottom flask equipped with a condenser and an oil-water separator. 20 mL of cyclohexane and p-toluenesulfonic acid (0.6 g, 0.003 mol) were added, and the mixture was reacted at 65 °C for 30 min. The reaction temperature was then raised to 125 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with 10% sodium bicarbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution, and the organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain heptanyl vanillyl lactate.
[0032] Heptyl vanillyl lactate (34 g, 0.1 mol), isobutyric anhydride (19 g, 0.12 mol), and 150 mL of ethyl acetate were added to a reaction vessel, and the mixture was heated under reflux for 2 h. The reaction was then stopped. The reaction solution was washed with saturated sodium carbonate solution until alkaline, and the supernatant was washed with deionized water until neutral. Finally, the solution was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain the bio-based plasticizer.
[0033] Compare with Example 1 The method is the same as in Example 1, except that lactic acid is not added.
[0034] Vanillic acid (16.8 g, 0.1 mol) and n-heptanol (14 g, 0.12 mol) were added to a round-bottom flask equipped with a condenser and an oil-water separator. 20 mL of cyclohexane and p-toluenesulfonic acid (0.6 g, 0.003 mol) were added, and the mixture was reacted at 65 °C for 30 min. The reaction temperature was then raised to 125 °C and refluxed until the acid value no longer decreased, at which point the reaction was stopped. The reaction solution was filtered, and the filtrate was collected, cooled to room temperature, washed with saturated sodium carbonate solution until alkaline, and then washed with deionized water until neutral. Finally, the mixture was washed with saturated sodium chloride solution, and the organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain heptyl vanillate.
[0035] Heptyl vanillate (26.6 g, 0.1 mol), isobutyric anhydride (15.8 g, 0.1 mol), and 150 mL of ethyl acetate were added to a reaction vessel, and the mixture was heated under reflux for 2 h. The reaction was then stopped. The reaction solution was washed with saturated sodium carbonate solution until alkaline, and the supernatant was washed with deionized water until neutral. Finally, the solution was washed with saturated sodium chloride solution. The organic phase was collected, dried over anhydrous sodium sulfate, and distilled under reduced pressure to obtain the bio-based plasticizer.
[0036] Preparation of polyvinyl chloride products The plasticizer, dioctyl phthalate (DOP), dioctyl terephthalate (DOTP), and tributyl acetyl citrate (ATBC) prepared in Example 1 and Comparative Example 1 were mixed with 100 parts by weight of polyvinyl chloride resin (K=71~72) according to the proportions in Table 1. Polyvinyl chloride film was prepared by tetrahydrofuran casting method, and its elongation at break, optical properties and glass transition temperature were tested. The results are shown in Table 2.
[0037] Table 1. Formulation of polyvinyl chloride products (parts by weight) Table 2 Performance test results of polyvinyl chloride products As shown in Table 2, compared to unplasticized PVC products, the glass transition temperature of PVC products plasticized with plasticizers is significantly lower, especially the PVC samples plasticized with the bio-based plasticizer described in this invention, which exhibit the lowest glass transition temperature. Furthermore, the PVC products plasticized with the bio-based plasticizer described in this invention exhibit better flexibility, with an elongation at break that is 12.7 times higher than that of pure PVC products. This indicates that the plasticizing effect of the bio-based plasticizer described in this invention is superior to commonly used plasticizers in the art, such as dioctyl phthalate, dioctyl terephthalate, and tributyl acetylacetonate. In addition, the PVC products plasticized with the bio-based plasticizer described in this invention show a trend towards high transmittance and low haze in optical properties, indicating its great potential in the application of flexible transparent plastics.
[0038] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A bio-based plasticizer, characterized in that, The structural formula of the bio-based plasticizer is as follows: 。 2. The method for preparing the bio-based plasticizer according to claim 1, characterized in that, The preparation method includes the following steps: (1) Vanillic acid is reacted with lactic acid to obtain vanillic acid lactate; (2) Vanillyl lactate was reacted with n-heptanol to obtain heptyl vanillyl lactate; (3) Heptyl vanillic acid lactate was reacted with isobutyric anhydride to obtain a bio-based plasticizer; The reaction equation is as follows: 。 3. The method for preparing the bio-based plasticizer according to claim 2, characterized in that: The molar ratio of vanillic acid to lactic acid is 1:(3~4).
4. The method for preparing the bio-based plasticizer according to claim 2, characterized in that: The molar ratio of vanillyl lactate to n-heptanol is 1:(1~1.2).
5. The method for preparing the bio-based plasticizer according to claim 2, characterized in that: The molar ratio of vanillic acid heptyl lactate to isobutyric anhydride is 1:(1~1.2).
6. A composite plasticizer comprising the bio-based plasticizer of claim 1.
7. The composite plasticizer according to claim 6, characterized in that: The composite plasticizer also includes one or more of the following: phthalate plasticizers, aliphatic diester plasticizers, epoxy plasticizers, phosphate plasticizers, citrate plasticizers, polyol ester plasticizers, polyester plasticizers, and chlorine-containing plasticizers.
8. The application of the bio-based plasticizer of claim 1 or the composite plasticizer of any one of claims 6 to 7 in polyvinyl chloride.
9. A polyvinyl chloride composite material, comprising polyvinyl chloride resin and the bio-based plasticizer of claim 1 or the composite plasticizer of any one of claims 6 to 7.
10. The polyvinyl chloride composite material according to claim 9, characterized in that: The polyvinyl chloride composite material also includes one or more of the following: fillers, dispersants, flame retardants, lubricants, stabilizers, antioxidants, and antibacterial agents.