A method for preparing biodegradable PBAT foam material
Functionalized polyacrylonitrile fibers prepared by blending extrusion and specific treatment have good compatibility with PBAT, solving the problem of low mechanical strength of PBAT foam materials and significantly improving their mechanical properties.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DONGGUAN HAILEX HIGH POLYMER MATERIAL SCI & TECH CO LTD
- Filing Date
- 2026-04-22
- Publication Date
- 2026-05-26
AI Technical Summary
In the existing technology, the compatibility between polyacrylonitrile fiber and PBAT is poor, resulting in low mechanical strength of PBAT foam material, making it difficult to effectively exert the reinforcing effect of the fiber.
Biodegradable PBAT foam material was prepared by co-extruding polybutylene terephthalate (PET), antioxidants, and functionalized polyacrylonitrile fibers in a twin-screw extruder, followed by injection molding and foaming under specific conditions. The cross-linked structure of the functionalized polyacrylonitrile fibers and the similar main chain structure of PBAT were used to improve compatibility.
It significantly improves the mechanical properties of PBAT foam materials, such as tensile strength, elongation at break, and tear strength, and achieves an effective reinforcing effect of fibers in PBAT.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of PBAT technology, specifically to a method for preparing a biodegradable PBAT foam material. Background Technology
[0002] Polybutylene terephthalate (PBAT) is a polyester copolymer with good tensile properties, heat resistance, and impact resistance. It is also biodegradable and has wide applications in biodegradable plastics, foam materials, and film materials. Improving the strength, tear resistance, and compression resistance of PBAT and its foam materials will facilitate its expansion in practical applications such as footwear materials, insulation boards, and thermal insulation materials.
[0003] Currently, the main methods for modifying PBAT include irradiation modification, grafting modification, and blending modification. Blending PBAT with high-performance fibers is also an effective way to improve its mechanical properties. Polyacrylonitrile fibers are inexpensive, have good tensile properties, and high modulus, making them well-suited for toughening and modifying polymer materials. However, the compatibility between polyacrylonitrile fibers and PBAT is poor, making it difficult to effectively utilize the reinforcing effect of the fibers. Summary of the Invention
[0004] The technical problem solved by this invention is to provide a method for preparing biodegradable PBAT foam material, which solves the problem of low mechanical strength of PBAT foam material.
[0005] The technical solution provided by this invention is: a method for preparing a biodegradable PBAT foam material. Step (1): Polybutylene terephthalate (PET), antioxidant, and functionalized polyacrylonitrile fiber are added to a twin-screw extruder, co-extruded, and then injection molded to obtain PBAT injection molded parts. The melt flow index of PET can be 2-8 g / 10min (190℃, 2.16kg).
[0006] Step (2): Place the PBAT injection molded part in an atmosphere furnace, introduce treatment gas, control the pressure to 40-50MPa, treat at 120-130℃ for 3-6h, and then depressurize within 20-25s; then place the PBAT in an oven and foam at 130-140℃ for 25-35min; finally, place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 115-125℃ for 8-10min, and water cool for 8-12min to shape, to obtain biodegradable PBAT foam material.
[0007] Preferably, in step (1), the extrusion temperature is 170-180℃, the screw speed is 30-50r / min, and the temperature of the four sections of the injection molding machine is 140-157℃.
[0008] Preferably, in step (2), the processing gas is nitrogen or a mixture of nitrogen and carbon dioxide in a volume ratio of (7.5-8.5):(1.5-2.5).
[0009] Preferably, the antioxidant is 0.2-0.4% of the mass of polybutylene terephthalate; the antioxidant is antioxidant 168 or antioxidant 1010.
[0010] Preferably, the mass of the functionalized polyacrylonitrile fiber is 1-6% of the mass of polybutylene terephthalate.
[0011] The preferred method for preparing functionalized polyacrylonitrile fibers is as follows: Step S1: At 0-5℃, terephthaloyl chloride, hydroxyethyl acrylate, and pyridine are added to toluene. After stirring, the mixture is reacted at 15-30℃ for 5-8 hours. The mixture is concentrated under reduced pressure, the product is washed with water, and then recrystallized in ethanol to obtain the diacrylate intermediate. The reaction formula is:
[0012] Step S2: Add acrylonitrile, diacrylate intermediate and sodium dodecyl sulfate to water, stir, add potassium persulfate under nitrogen atmosphere, heat to 60-70℃, react for 6-8 hours, filter, wash with water and ethanol, and dry to obtain functionalized polyacrylonitrile.
[0013] Step S3: Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 10-15%. Then spin the solution using an electrospinning machine, controlling the voltage at 25-30kV and the spinning solution flow rate at 0.3-0.8mL / h. Collect the fibers to obtain functionalized polyacrylonitrile fibers.
[0014] Preferably, in step S1, the mass of hydroxyethyl acrylate and pyridine is 114-130% and 80-90% of the mass of terephthaloyl chloride, respectively.
[0015] Preferably, in step S2, the mass of the diacrylate intermediate, sodium dodecyl sulfate, and potassium persulfate is 2-6%, 1.5-2.2%, and 0.6-0.8% of the mass of acrylonitrile, respectively.
[0016] The present invention has the following technical effects: The present invention utilizes acrylonitrile and diacrylate intermediates for cross-linking polymerization reaction, followed by electrospinning to obtain functionalized polyacrylonitrile fibers that fill and modify PBAT. After cross-linking, the resulting fibers have better mechanical properties and contain terephthalate structures in their main chain, while PBAT contains butylene terephthalate monomers. The similarity in their structures results in good interfacial compatibility between the functionalized polyacrylonitrile fibers and PBAT. Adding them to PBAT can effectively improve the tensile strength, elongation at break, tear strength, and other properties of PBAT foam materials, exhibiting better mechanical properties. Detailed Implementation
[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0018] The following polybutylene terephthalate (PET) is designated as Ecoflex® F Blend C1200 by BASF, Germany.
[0019] Example 1 (1) At 0℃, 0.5g of terephthaloyl chloride, 0.57g of hydroxyethyl acrylate, and 0.45g of pyridine were added to 8mL of toluene. After stirring, the mixture was reacted at 20℃ for 8h. The mixture was concentrated under reduced pressure, the product was washed with water, and then recrystallized in ethanol to obtain the diacrylate intermediate. The structural formula is as follows: .
[0020] (2) Add 10g acrylonitrile, 0.4g diacrylate intermediate and 0.2g sodium dodecyl sulfate to 80mL of water, stir and add 72mg potassium persulfate under nitrogen atmosphere, heat to 70℃, react for 6h, filter, wash with water and ethanol, dry to obtain functionalized polyacrylonitrile.
[0021] (3) Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 12%, and then spin it through an electrospinning machine with a voltage of 30kV and a spinning solution flow rate of 0.5mL / h. Collect the fiber to obtain functionalized polyacrylonitrile fiber.
[0022] (4) Add 1 kg of dry polybutylene terephthalate, 2.6 g of antioxidant 168, and 10 g of functionalized polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 30 r / min and the extrusion temperature is 175℃. After blending and extrusion, the mixture is then injection molded. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0023] (5) Place the PBAT injection molded part in an atmosphere furnace, introduce nitrogen gas, control the pressure to 45MPa, treat at 125℃ for 6h, and then depressurize within 20s; then place the PBAT in an oven and foam at 135℃ for 30min; finally place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 120℃ for 8min, and water cool for 8min to shape, to obtain biodegradable PBAT foam material.
[0024] Example 2 (1) At 0℃, 0.5g terephthaloyl chloride, 0.65g hydroxyethyl acrylate and 0.45g pyridine were added to 10mL toluene. After stirring, the mixture was reacted at 15℃ for 8h. The mixture was concentrated under reduced pressure, the product was washed with water, and then recrystallized in ethanol to obtain the diacrylate intermediate.
[0025] (2) Add 10g acrylonitrile, 0.6g diacrylate intermediate and 0.22g sodium dodecyl sulfate to 100mL of water, stir and add 80mg potassium persulfate in a nitrogen atmosphere, heat to 60℃ and react for 8h, filter, wash with water and ethanol, and dry to obtain functionalized polyacrylonitrile.
[0026] (3) Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 10%, and then spin it through an electrospinning machine with a voltage of 30kV and a spinning solution flow rate of 0.3mL / h. Collect the fiber to obtain functionalized polyacrylonitrile fiber.
[0027] (4) Add 1 kg of dry polybutylene terephthalate, 4 g of antioxidant 1010, and 35 g of functionalized polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 50 r / min and the extrusion temperature is 170℃. After blending and extrusion, the mixture is then injected into an injection molding machine. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0028] (5) Place the PBAT injection molded part in an atmosphere furnace, introduce a mixture of nitrogen and carbon dioxide with a volume ratio of 8:2, control the pressure at 50MPa, treat at 120℃ for 6h, and then depressurize within 20s; then place the PBAT in an oven and foam at 140℃ for 25min; finally place the foamed material in a mold, place it in a hot pressing and cooling shaping equipment, hot press at 115℃ for 10min, and water cool for 12min to shape, and obtain biodegradable PBAT foam material.
[0029] Example 3 (1) At 5°C, 0.5 g terephthaloyl chloride, 0.62 g hydroxyethyl acrylate, and 0.4 g pyridine were added to 6 mL of toluene. After stirring, the mixture was reacted at 30°C for 5 h. The mixture was concentrated under reduced pressure, the product was washed with water, and then recrystallized in ethanol to obtain the diacrylate intermediate.
[0030] (2) Add 10g acrylonitrile, 0.2g diacrylate intermediate and 0.15g sodium dodecyl sulfate to 80mL of water, stir and add 60mg potassium persulfate in a nitrogen atmosphere, heat to 60℃ and react for 8h, filter, wash with water and ethanol, and dry to obtain functionalized polyacrylonitrile.
[0031] (3) Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 15%, and then spin it through an electrospinning machine with a voltage of 25kV and a spinning solution flow rate of 0.8mL / h. Collect the fiber to obtain functionalized polyacrylonitrile fiber.
[0032] (4) Add 1 kg of dry polybutylene terephthalate, 2 g of antioxidant 168, and 60 g of functionalized polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 50 r / min and the extrusion temperature is 180℃. After blending and extrusion, the mixture is then injected into an injection molding machine. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0033] (5) Place the PBAT injection molded part in an atmosphere furnace, introduce nitrogen gas, control the pressure to 40MPa, treat at 130℃ for 3h, and then depressurize within 20s; then place the PBAT in an oven and foam at 130℃ for 35min; finally place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 125℃ for 8min, and water cool for 10min to shape, and obtain biodegradable PBAT foam material.
[0034] Comparative Example 1 (1) Add 10g acrylonitrile and 0.2g sodium dodecyl sulfate to 80mL of water, stir, add 72mg potassium persulfate under a nitrogen atmosphere, heat to 70℃, react for 6h, filter, wash with water and ethanol, and dry to obtain polyacrylonitrile.
[0035] (2) Add polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 12%. Then spin the solution using an electrospinning machine, control the voltage at 30kV and the spinning solution flow rate at 0.5mL / h, collect the fibers and obtain polyacrylonitrile fibers.
[0036] (3) Add 1 kg of dry polybutylene terephthalate, 2.6 g of antioxidant 168, and 10 g of polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 30 r / min and the extrusion temperature is 175℃. After blending and extrusion, the mixture is then injected into an injection molding machine. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0037] (4) Place the PBAT injection molded part in an atmosphere furnace, introduce nitrogen gas, control the pressure to 45MPa, treat at 125℃ for 6h, and then depressurize within 20s; then place the PBAT in an oven and foam at 135℃ for 30min; finally place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 120℃ for 8min, and water cool for 8min to shape, to obtain biodegradable PBAT foam material.
[0038] Comparative Example 2 (1) Add 10g acrylonitrile and 0.4g ethylene glycol diacrylate (CAS No. 2274-11-5, structural formula: ) to 80mL of water. 0.2 g of sodium dodecyl sulfate was added under a nitrogen atmosphere and stirred. 72 mg of potassium persulfate was added and heated to 70 °C. The mixture was reacted for 6 h, filtered, washed with water and ethanol, and dried to obtain functionalized polyacrylonitrile.
[0039] (2) Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 12%, and then spin it through an electrospinning machine with a voltage of 30kV and a spinning solution flow rate of 0.5mL / h. Collect the fiber to obtain functionalized polyacrylonitrile fiber.
[0040] (3) Add 1 kg of dry polybutylene terephthalate, 2.6 g of antioxidant 168, and 10 g of functionalized polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 30 r / min and the extrusion temperature is 175℃. After blending and extrusion, the mixture is then injected into an injection molding machine. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0041] (4) Place the PBAT injection molded part in an atmosphere furnace, introduce nitrogen gas, control the pressure to 45MPa, treat at 125℃ for 6h, and then depressurize within 20s; then place the PBAT in an oven and foam at 135℃ for 30min; finally place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 120℃ for 8min, and water cool for 8min to shape, to obtain biodegradable PBAT foam material.
[0042] Comparative Example 3 (1) At 0℃, 0.346g benzoyl chloride, 0.57g hydroxyethyl acrylate, and 0.45g pyridine were added to 8mL of toluene. After stirring, the mixture was reacted at 20℃ for 8h. The mixture was concentrated under reduced pressure, the product was washed with water, and then recrystallized in ethanol to obtain the acrylate intermediate. The structural formula is as follows: .
[0043] (2) Add 10g acrylonitrile, 0.4g acrylate intermediate and 0.2g sodium dodecyl sulfate to 80mL of water, stir and add 72mg potassium persulfate in a nitrogen atmosphere, heat to 70℃, react for 6h, filter, wash with water and ethanol, dry to obtain functionalized polyacrylonitrile.
[0044] (3) Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain a spinning solution with a mass fraction of 12%, and then spin it through an electrospinning machine with a voltage of 30kV and a spinning solution flow rate of 0.5mL / h. Collect the fiber to obtain functionalized polyacrylonitrile fiber.
[0045] (4) Add 1 kg of dry polybutylene terephthalate, 2.6 g of antioxidant 168, and 10 g of functionalized polyacrylonitrile fiber to a twin-screw extruder. The screw speed is 30 r / min and the extrusion temperature is 175℃. After blending and extrusion, the mixture is then injection molded. The four temperature sections of the injection molding machine are 140℃, 145℃, 148℃, and 157℃ to obtain PBAT injection molded parts.
[0046] (5) Place the PBAT injection molded part in an atmosphere furnace, introduce nitrogen gas, control the pressure to 45MPa, treat at 125℃ for 6h, and then depressurize within 20s; then place the PBAT in an oven and foam at 135℃ for 30min; finally place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 120℃ for 8min, and water cool for 8min to shape, to obtain biodegradable PBAT foam material.
[0047] Tensile strength and elongation at break were tested according to ASTM-D412.
[0048] Tear strength was tested according to ASTM-D3574.
[0049] Test the compression set properties according to ASTM-D395.
[0050] Test the hardness according to the ASTM-D2240 method.
[0051] The test results of the PBAT foam material performance test are shown in Table 1.
[0052] Table 1 Performance Tests of PBAT Foaming Materials
[0053] In Examples 1-3, functionalized polyacrylonitrile fibers were filled with PBAT for modification. After crosslinking, the mechanical properties of the polyacrylonitrile fibers were improved, and the main chain contained terephthalate structures. PBAT contains butylene terephthalate monomers, and the two have similar structures, which makes functionalized polyacrylonitrile fibers and PBAT have good interfacial compatibility. Polyacrylonitrile fibers have advantages such as good tensile properties, high strength, and high tear strength. Adding them to PBAT can effectively improve the tensile strength, elongation at break, tear strength and other properties of PBAT foam materials.
[0054] In Comparative Example 1, no diacrylate intermediate was added during the preparation of polyacrylonitrile. As a result, the polyacrylonitrile fiber did not contain terephthalate structure, had poor compatibility with PBAT, poor reinforcement effect, and only a small increase in mechanical properties such as tensile strength and elongation at break.
[0055] In Comparative Example 2, conventional ethylene glycol diacrylate was added during the preparation of functionalized polyacrylonitrile. The main chain of the resulting polyacrylonitrile fiber did not contain terephthalate structure, resulting in poor compatibility with PBAT and poor reinforcement effect. Consequently, the increase in mechanical properties such as tensile strength and elongation at break was smaller than that in Example 1.
[0056] The acrylate intermediate in Comparative Example 3 contains only one alkenyl group. The functionalized polyacrylonitrile has not undergone cross-linking polymerization, and its mechanical properties are lower than those of the functionalized polyacrylonitrile in Example 1. As a result, the increase in mechanical properties such as tensile strength and elongation at break of PBAT is smaller than that in Example 1.
[0057] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for preparing a biodegradable PBAT foam material, characterized in that, The preparation method is as follows: Step (1): Add polybutylene terephthalate (PET) and additives to a twin-screw extruder, co-extrude, and then perform injection molding to obtain PBAT injection molded parts; Step (2): Place the PBAT injection molded part in an atmosphere furnace, introduce treatment gas, control the pressure to 40-50MPa, treat at 120-130℃ for 3-6h, and then depressurize within 20-25s; then place the PBAT in an oven and foam at 130-140℃ for 25-35min; finally, place the foamed material in a mold, place it in a hot press cooling and shaping equipment, hot press at 115-125℃ for 8-10min, and water cool for 8-12min to shape, to obtain biodegradable PBAT foam material.
2. The method for preparing biodegradable PBAT foam material according to claim 1, characterized in that, In step (1), the extrusion temperature is 170-180℃, the screw speed is 30-50r / min, and the temperature of the four sections of the injection molding machine is 140-157℃.
3. The method for preparing biodegradable PBAT foam material according to claim 1, characterized in that, In step (2), the processing gas is nitrogen or a mixture of nitrogen and carbon dioxide in a volume ratio of (7.5-8.5):(1.5-2.5).
4. The method for preparing biodegradable PBAT foam material according to claim 1, characterized in that, The additives include antioxidants, the mass of which is 0.2-0.4% of the mass of polybutylene terephthalate; the antioxidants are antioxidant 168 and antioxidant 1010.
5. The method for preparing biodegradable PBAT foam material according to claim 1, characterized in that, The additives also include functionalized polyacrylonitrile fibers, the mass of which is 1-6% of the mass of polybutylene terephthalate.
6. The method for preparing biodegradable PBAT foam material according to claim 5, characterized in that, The preparation method of the functionalized polyacrylonitrile fiber is as follows: Step S1: At 0-5℃, terephthaloyl chloride, hydroxyethyl acrylate and pyridine are added to toluene. After stirring, the mixture is reacted at 15-30℃ for 5-8 hours. The mixture is concentrated under reduced pressure, washed and recrystallized to obtain the diacrylate intermediate. Step S2: Add acrylonitrile, diacrylate intermediate and sodium dodecyl sulfate to water, stir, add potassium persulfate under nitrogen atmosphere, heat to 60-70℃, react for 6-8 hours, filter, wash and dry to obtain functionalized polyacrylonitrile. Step S3: Add functionalized polyacrylonitrile to N,N-dimethylformamide, stir and let stand to remove bubbles to obtain spinning solution, then spin it through an electrospinning machine, collect the fibers, and obtain functionalized polyacrylonitrile fibers.
7. The method for preparing biodegradable PBAT foam material according to claim 6, characterized in that, In step S1, the mass of hydroxyethyl acrylate and pyridine is 114-130% and 80-90% of the mass of terephthaloyl chloride, respectively.
8. The method for preparing biodegradable PBAT foam material according to claim 6, characterized in that, In step S2, the mass of the diacrylate intermediate, sodium dodecyl sulfate, and potassium persulfate is 2-6%, 1.5-2.2%, and 0.6-0.8% of the mass of acrylonitrile, respectively.
9. The method for preparing the biodegradable PBAT foam material according to claim 6, characterized in that, In step S3, the mass fraction of the spinning solution is 10-15%; the voltage during spinning is 25-30kV; and the flow rate of the spinning solution is 0.3-0.8mL / h.