Synergistic plasticizing / compatibilizing aid for composite material as well as preparation method and application of synergistic plasticizing / compatibilizing aid
By preparing levulinic acid-malic acid-glycidyl ester additives, the interfacial compatibility and processing flowability problems of bamboo powder composites were solved, thereby improving the material properties and stability and broadening the application scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-02
- Publication Date
- 2026-04-03
AI Technical Summary
Bamboo powder composites suffer from poor interfacial compatibility and insufficient processing fluidity, leading to decreased mechanical properties and high processing energy consumption. Traditional single additives are difficult to simultaneously reduce processing resistance and strengthen interfacial bonding, and the combination of multiple additives can easily cause phase separation and additive migration, reducing the long-term stability of the material.
A levulinic acid-malic acid-glycidyl ester additive was prepared by a two-step esterification reaction using levulinic acid, DL-malic acid and glycidyl as the main raw materials. This additive has both polar groups that have plasticizing properties and epoxy groups that promote compatibility, and is used to improve the interfacial adhesion of bamboo powder composites.
It improves the elongation at break of bamboo powder composites, broadens the application scenarios, improves the plasticizing ability and compatibility of materials, enhances the long-term stability and surface smoothness of materials, and the additives have good biocompatibility and biodegradability.
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Abstract
Description
Technical Field
[0001] This invention relates to an additive for composite materials, its preparation method and application, and more particularly to a synergistic plasticizer / compensator for composite materials, its preparation method and application. Background Technology
[0002] Bamboo-based composite materials (BFRCs) are environmentally friendly materials using bamboo powder as the reinforcing phase and thermoplastic polymers (such as PLA, PBAT, PP, etc.) as the matrix. They combine the renewability and low density of natural fibers with the processability of polymers, showing great promise in packaging, construction, and automotive interiors. However, their industrialization faces two major bottlenecks: 1) Poor interfacial compatibility: Bamboo powder is rich in hydroxyl groups (-OH), making it hydrophilic; while the polymer matrix is hydrophobic, resulting in weak interfacial bonding, low stress transfer efficiency, and decreased material mechanical properties. 2) Insufficient processing fluidity: High filler content (>30%) of bamboo powder significantly increases melt viscosity, leading to high processing energy consumption, rough product surfaces, and bamboo powder is prone to thermal degradation during high-temperature processing.
[0003] Traditional solutions typically involve adding plasticizers and compatibilizers. However, a single additive can hardly achieve both "reducing processing resistance" and "strengthening interfacial bonding" simultaneously. Furthermore, the combination of multiple additives can easily lead to phase separation and additive migration, reducing the long-term stability of the material and even causing safety issues.
[0004] Therefore, developing an integrated additive that combines plasticizing and compatibilizing functions is key to breaking through the performance bottleneck of bamboo powder composites. Summary of the Invention
[0005] Purpose of the invention: The purpose of this invention is to provide a synergistic plasticizer / compensator for composite materials that can simultaneously achieve "reduced processing resistance" and "strengthened interfacial bonding";
[0006] A second objective of this invention is to provide a method for preparing the aforementioned synergistic plasticizer / compatibilizer for composite materials;
[0007] A third objective of this invention is to provide the application of the aforementioned synergistic plasticizer / compostor for composite materials in the preparation of bamboo powder composite materials.
[0008] Technical solution: The synergistic plasticizer / compressor for composite materials described in this invention has the following structural formula:
[0009] .
[0010] The preparation method of the above-mentioned synergistic plasticizer / compatibilizer for composite materials includes the following steps:
[0011] (1) Mix DL-malic acid, levulinic acid and catalyst and heat. After the reaction is complete, extract the crude product, wash until neutral, remove the solvent by rotary evaporation to obtain levulinic acid-malic acid ester.
[0012] (2) Mix levulinic acid-malate, glycidyl and catalyst and heat. After the reaction is complete, extract the crude product, wash until neutral, and then remove the solvent by rotary evaporation to obtain levulinic acid-malate-glycidyl ester.
[0013] In step (1), the catalyst is p-toluenesulfonic acid, and the mass of the catalyst is 0.4% to 0.8% of the total mass of the raw materials.
[0014] In step (1), the molar ratio of DL-malic acid and levulinic acid is 1:1.2 to 1.5.
[0015] In step (1), the temperature is heated to 140–180 °C and the reaction is carried out for 3–6 h. If the temperature is too low, the optimal activity temperature of the catalyst cannot be reached, and if the temperature is too high, the color of the reactants will darken.
[0016] In step (1), the vacuum degree of rotary evaporation is -0.1 MPa, and the distillation is carried out at 75-95 °C for 1-3 h. Under these conditions, the residue can be reduced and the distillation can be ensured as thoroughly as possible.
[0017] In step (2), the catalyst is stannous chloride, and the mass of the catalyst is 10-20% of the molar mass of levulinic acid-malate.
[0018] In step (2), the molar ratio of levulinic acid-malate and glycidyl is 1:2.5 to 3.5.
[0019] In step (2), the temperature is heated to 150–200 °C and the reaction is carried out for 5–8 h; the vacuum degree of rotary evaporation is -0.1 MPa, and the distillation is carried out at 75–95 °C for 1–3 h.
[0020] This invention provides the application of the above-mentioned synergistic plasticizer / compostor in the preparation of bamboo powder composite materials.
[0021] Invention Principle: This invention utilizes structural design of bio-based raw materials to obtain a synergistic plasticizer / compensator for composite materials rich in multiple functional groups. This additive possesses both polar groups for plasticizing properties and epoxy groups for promoting compatibility. When used in the preparation of bamboo powder composite materials, it can both embed itself into polymer molecules through flexible molecular chains, weakening interchain forces, reducing melt viscosity, and improving processing performance; and it can also form a stable "bamboo powder-additive-polymer" structure through chemical reactions or hydrogen bonding between the active epoxy groups and the hydroxyl groups on the bamboo powder surface, strengthening interfacial adhesion. Therefore, the additive of this invention can improve the plasticizing ability and compatibility of materials, and alleviate problems such as poor interfacial compatibility between bamboo powder and other polymer materials, and rough product surfaces.
[0022] Beneficial effects: Compared with the prior art, the present invention achieves the following significant effects: (1) The present invention uses levulinic acid, DL-malic acid and glycidyl ester as the main raw materials, and obtains the final product that meets the requirements through a two-step esterification reaction. The levulinic acid-malic acid-glycidyl ester additive prepared by this method has low viscosity, is a light yellow transparent liquid, and has good compatibility with polymers such as PLA and PVC. Because its molecular structure contains more polar groups and special epoxy structure, the additive has both plasticizing effect and can promote the compatibility of the two phases in the "polymer-filler" system, thereby improving the long-term stability of the material. (2) The addition of the additive of the present invention can improve the elongation at break of bamboo powder composite materials and broaden the application scenarios. (3) The levulinic acid-malic acid-glycidyl ester additive of the present invention uses biomass raw materials, and has good biocompatibility and biodegradability. Attached Figure Description
[0023] Figure 1 Scanning electron microscope images of the three bamboo powder composite materials and the comparative sample in Application Example 1. Detailed Implementation
[0024] The present invention will now be described in further detail.
[0025] Example 1
[0026] (1) First step of esterification reaction: DL-malic acid, levulinic acid and catalyst p-toluenesulfonic acid are added to the reactor and heated to react; the molar ratio of DL-malic acid and levulinic acid is 1:1.2, the mass of catalyst is 0.5% of the total mass of raw materials, heated to 140°C and reacted for 4h; after the reaction, the crude product is first extracted with ethyl acetate, then washed with deionized water until neutral, and then vacuum distilled for 2h at -0.1MPa and 80°C to remove residual water and ethyl acetate to obtain levulinic acid-malic acid ester;
[0027] (2) Second step esterification reaction: The levulinic acid-malate obtained in step (1) and glycidyl chloride and the catalyst stannous chloride are added to the reactor and heated for reaction. The molar ratio of levulinic acid-malate and glycidyl chloride is 1:2.5, and the mass of the catalyst is 10-20% of the molar mass of levulinic acid-malate. The heating temperature is 160°C and the reaction time is 6h. After the reaction is completed, the crude product is extracted with ethyl acetate and washed with deionized water until neutral. Then, the residual water and ethyl acetate are removed by vacuum distillation at -0.1MPa and 80°C for 2h to obtain levulinic acid-malate-glycidyl ester, which is the plasticizer / compressor dual-effect additive.
[0028] Example 2
[0029] (1) First step of esterification reaction: DL-malic acid, levulinic acid and catalyst p-toluenesulfonic acid are added to the reactor and heated to react; the molar ratio of DL-malic acid and levulinic acid is 1:1.5, the mass of catalyst is 0.5% of the total mass of raw materials, heated to 160°C and reacted for 5h; after the reaction, the crude product is first extracted with ethyl acetate, then washed with deionized water until neutral, and then vacuum distilled for 2h at -0.1MPa and 85°C to remove residual water and ethyl acetate to obtain levulinic acid-malic acid ester;
[0030] (2) Second step esterification reaction: The levulinic acid-malate obtained in step (1) and glycidyl chloride and the catalyst stannous chloride are added to the reactor and heated for reaction. The molar ratio of levulinic acid-malate to glycidyl chloride is 1:3, and the mass of the catalyst is 10-20% of the molar mass of levulinic acid-malate. The heating temperature is 170°C and the reaction is carried out for 7 hours. After the reaction is completed, the crude product is first extracted with ethyl acetate, washed with deionized water until neutral, and then vacuum distilled for 2 hours at -0.1 MPa and 85°C to remove residual water and ethyl acetate, so as to obtain levulinic acid-malate-glycidyl ester.
[0031] Comparative Example 1
[0032] (1) First step of esterification reaction: DL-malic acid, levulinic acid and the catalyst p-toluenesulfonic acid were added to the reactor and heated for reaction; the molar ratio of DL-malic acid to levulinic acid was 1:2, the mass of the catalyst was 0.5% of the total mass of the raw materials, and the temperature was raised to 140°C for 4 hours; after the reaction, the crude product was first extracted with ethyl acetate and then washed with deionized water. However, due to the excess of levulinic acid during feeding, a large amount of acid residue was caused, which required washing with a large amount of deionized water to reach neutrality, resulting in a large loss and yielding a small amount of levulinic acid-malic acid ester. 02
[0033] (2) Second step esterification reaction: The levulinic acid-malate obtained in step (1) and glycidyl chloride and the catalyst stannous chloride are added to the reactor and heated for reaction. The molar ratio of levulinic acid-malate and glycidyl chloride is 1:2.5, and the mass of the catalyst is 10-20% of the molar mass of levulinic acid-malate. The heating temperature is 160°C and the reaction time is 6h. After the reaction is completed, the crude product is extracted with ethyl acetate and washed with deionized water until neutral. Then, the residual water and ethyl acetate are removed by vacuum distillation at -0.1MPa and 80°C for 2h to obtain levulinic acid-malate-glycidyl ester, which is the plasticizer / compressor dual-effect additive.
[0034] Comparative Example 2
[0035] Step 1: Esterification reaction: DL-malic acid, levulinic acid and the catalyst p-toluenesulfonic acid were added to the reactor and heated to react. The molar ratio of DL-malic acid to levulinic acid was 1:1.2, and the mass of the catalyst was 0.5% of the total mass of the raw materials. The mixture was heated to 190°C and reacted for 5 hours. After the reaction was completed, the crude product was first extracted with ethyl acetate, then washed with deionized water until neutral. After that, the product was vacuum distilled at -0.1 MPa and 85°C for 2 hours to remove residual water and ethyl acetate, yielding levulinic acid-malic acid ester.
[0036] However, due to the excessively high reaction temperature, the product, levulinic acid-malate, was too yellow and could not meet the application requirements, so the second step of the reaction was not carried out.
[0037] Comparative Example 3
[0038] Step 1: Esterification reaction: DL-malic acid, levulinic acid and the catalyst p-toluenesulfonic acid were added to the reactor and heated to react. The molar ratio of DL-malic acid to levulinic acid was 1:1.2, and the mass of the catalyst was 0.5% of the total mass of the raw materials. The mixture was heated to 140°C and reacted for 8 hours. After the reaction was completed, the crude product was first extracted with ethyl acetate, then washed with deionized water until neutral, and then vacuum distilled at -0.1 MPa and 85°C for 2 hours to remove residual water and ethyl acetate, to obtain levulinic acid-malic acid ester.
[0039] However, due to the excessively long reaction time and the failure to stop and process the product in time, the product, levulinic acid-malate, was yellow in color and could not meet the application requirements. Therefore, the second step of the reaction was not carried out.
[0040] Related tests:
[0041] Thermogravimetric tests were respectively carried out on levulinic acid - malic acid - glycidyl ester in Example 1, commercial plasticizer tributyl acetylcitrate (ATBC) and dioctyl terephthalate (DOTP). The specific thermogravimetric results are shown in Table 1; the data in Table 1 are respectively the initial decomposition temperature T i of plasticizer DOTP, ATBC and levulinic acid - malic acid - glycidyl ester in Example 1, the corresponding temperature T 10 when decomposed by 10%, the corresponding temperature T 50 when decomposed by 50%, and the fastest decomposition temperature T p .
[0042] Table 1 Thermogravimetric test results of bamboo powder composite samples
[0043]
[0044] From the data in Table 1, it can be seen that compared with plasticizers DOTP and ATBC, the initial decomposition temperature T i of levulinic acid - malic acid - glycidyl ester in Example 1 is the highest, about 257.89 °C, indicating that there are basically no small - molecule impurities in the levulinic acid - malic acid - glycidyl ester prepared in Example 1 and its thermal stability is excellent.
[0045] Since the thermal stability of the additive is largely related to its molecular structure, therefore, the levulinic acid - malic acid - glycidyl ester prepared in Example 1 of the present invention has a relatively stable glycidyl structure and can exhibit better thermal stability than DOTP and ATBC.
[0046] Application Example 1
[0047] Polylactic acid, poly(butylene adipate - co - terephthalate), bamboo powder, and the plasticizing / encompatibilizing dual - effect additive in Example 1 were mixed, melt - extruded, and granulated according to a mass ratio of 20 - 40:20 - 40:15 - 40:5 - 25; among them, the conditions for melt - extrusion were: the screw speed was 200 - 300 rpm, the feeding speed was 3 - 6 Hz, and the extrusion temperature zone was set at 140 - 200 °C. After granulation and drying, standard samples were obtained by an injection molding machine. Tensile tests and scanning electron microscope tests were carried out on the obtained bamboo powder composite samples.
[0048] The DOTP plasticizer and ATBC plasticizer in the prior art were respectively used to prepare comparative samples by the same steps as in Application Example 1.
[0049] Tensile property tests were respectively carried out on the bamboo powder composite sample prepared in Application Example 1 using the additive prepared in Example 1 of the present invention and three comparative bamboo powder composite samples, and the tests were carried out at a speed of 50 mm / min. The specific test results are shown in Table 2.
[0050] Table 2 Tensile test results of bamboo powder composite samples
[0051]
[0052] The data in Table 2 show that the levulinic acid-malic acid-glycidyl ester prepared by the method of the present invention can improve the fracture productivity and flexibility of bamboo powder composite materials.
[0053] The bamboo powder composite material sample prepared using the product of this invention in Application Example 1 and three comparative bamboo powder composite material samples were subjected to scanning electron microscopy tests. Specific test results are as follows: Figure 1 As shown in the figure. Among them, (a), (b), (e), and (f) are samples of levulinic acid-malic acid-glycidyl ester bamboo powder composite material, bamboo powder composite material without additives, DOTP-modified bamboo powder composite material, and ATBC-modified bamboo powder composite material, respectively. Figure 1 It can be seen that the surface of the bamboo powder composite sample without additives is relatively rough, with obvious black pores, exhibiting poor compatibility and uniformity. When levulinic acid-malic acid-glycidyl ester, which has both plasticizing and compatibilizing effects, is added, the sample surface becomes smooth, the pores basically disappear, and it shows better compatibility, and the effect is better than the comparative additives acetylated tributyl citrate (ATBC) and dioctyl terephthalate (DOTP).
[0054] This invention uses levulinic acid, DL-malic acid, and glycidyl ester as main raw materials. By optimizing factors such as temperature, feed ratio, and reaction time, suitable reaction conditions for synthesizing the additive were finally explored, resulting in the final product, levulinic acid-malic acid-glycidyl ester additive. This additive is highly compatible with polymers such as PLA and PVC and plays a plasticizing role. Due to the presence of numerous polar groups and a unique epoxy structure in its molecular structure, this additive not only plasticizes the polymer-filler system but also promotes the compatibility of the two phases, improving the long-term stability of the material.
Claims
1. A synergistic plasticizer / compatibilizer for composite materials, characterized in that, Its structural formula is shown below: 。 2. A method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 1, characterized in that, Includes the following steps: (1) Mix DL-malic acid, levulinic acid and catalyst and heat. After the reaction is complete, extract the crude product, wash until neutral, remove the solvent by rotary evaporation to obtain levulinic acid-malic acid ester. (2) Mix levulinic acid-malate, glycidyl and catalyst and heat. After the reaction is complete, extract the crude product, wash until neutral, and then remove the solvent by rotary evaporation to obtain levulinic acid-malate-glycidyl ester.
3. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, In step (1), the catalyst is p-toluenesulfonic acid, and the mass of the catalyst is 0.4% to 0.8% of the total mass of the raw materials.
4. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, In step (1), the molar ratio of DL-malic acid and levulinic acid is 1:1.2 to 1.
5.
5. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, In step (2), the catalyst is stannous chloride, and the mass of the catalyst is 10-20% of the molar mass of levulinic acid-malate.
6. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, In step (2), the molar ratio of levulinic acid-malate and glycidyl is 1:2.5 to 3.
5.
7. The preparation method for synergistic plasticizing / compressing of composite materials according to claim 2, characterized in that, In step (1), the temperature is heated to 140–180 °C and the reaction is carried out for 3–6 h.
8. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, In step (2), the temperature is heated to 150–200 °C and the reaction is carried out for 5–8 h.
9. The method for preparing the synergistic plasticizer / compatibilizer for composite materials according to claim 2, characterized in that, The vacuum degree of rotary evaporation in step (1) is -0.1 MPa, and the distillation is carried out at 75-95 °C for 1-3 h; the vacuum degree of rotary evaporation in step (2) is -0.1 MPa, and the distillation is carried out at 75-95 °C for 1-3 h.
10. The application of the synergistic plasticizer / composting agent for composite materials according to claim 1 in the preparation of bamboo powder composite materials.