Reed short fiber / PBAT biodegradable film blowing material and preparation method thereof
By preparing reed staple fibers with controllable aspect ratio and composited with PBAT resin, the problems of high production cost of PBAT biodegradable materials and poor interfacial tangling effect are solved, and the preparation of high-performance biodegradable membranes is achieved.
Patent Information
- Application Number
- CN202510531477.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2025-08-01
AI Technical Summary
The existing PBAT biodegradable materials have high production costs, low tensile strength and rigidity, and have low fiber content and severe powdering during the reed powder modification process, resulting in poor interfacial tangle enhancement effect.
Reed staple fibers are prepared by mechanical processing and caustic soda cooking. Combined with high mixing machine and twin-screw extrusion technology, reed staple fibers with controllable aspect ratio are prepared and PBAT resin are combined to avoid powdering and strengthen interface entanglement, and biodegradable blown film materials are prepared.
It effectively improves the mechanical properties of PBAT resin, reduces production costs, and improves the comprehensive performance of biodegradable membranes, meeting the production requirements of film products such as disposable shopping bags and garbage bags.
Smart Images
Figure CN120399415A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of biodegradable polymer materials, and relates to a reed short fiber / poly(butylene adipate-co-terephthalate) (PBAT) biodegradable blown film material and a preparation method thereof. Background Art
[0002] PBAT can be completely degraded into carbon dioxide and water through the action of microorganisms in the natural environment (such as soil, composting conditions). It is the mainstream material in the current field of biodegradable plastics, with both the flexibility of aliphatic polyesters and the strength, ductility and heat resistance (melting point about 130 °C) of aromatic polyesters, and good impact resistance, suitable for processing products such as films and packaging. However, compared with traditional plastics such as polyethylene, its production cost is higher, and its tensile strength and rigidity are lower. To overcome the above deficiencies, researchers usually introduce cheap materials such as calcium carbonate, starch, reed powder, straw powder, cellulose, lignin, etc. for blending modification, and use coupling agents (such as silanes), plasticizers or compatibilizers to improve the interface between components. Its disadvantages are that not only the cost increases, but also the degradation performance will be affected.
[0003] Among various modified materials, reed powder is a natural biodegradable material with a high cellulose content and is a high-quality raw material for papermaking, man-made fibers and woven handicrafts. Using it as a filler to modify PBAT can effectively improve its strength and modulus. However, commercially available mechanically pulverized reed powder is usually used for polymer modification, which not only has a complex composition (including different components such as the stems, stalks and leaves of reeds, and the components with less fiber content reduce its reinforcement effect), but also has serious pulverization, and its microscopic morphology is mostly irregular pellets rather than one-dimensional linear morphology, resulting in poor fiber characteristics and entanglement reinforcement effect, so various additives are needed to improve the interfacial action.
[0004] In summary, there is an urgent need to find a degraded reed powder / PBAT blown film composite material and a preparation method thereof to meet the production requirements of thin film products such as disposable degradable shopping bags and garbage bags. Summary of the Invention
[0005] The purpose of the present invention is to provide a reed short fiber-PBAT biodegradable blown film material and a preparation method thereof by strengthening the interfacial action between components by physical methods in view of the above deficiencies of the prior art.
[0006] To solve the above problems, the technical solution of the present invention is as follows: A reed short fiber / PBAT resin biodegradable blown film material, and its preparation raw materials include the following components in parts by weight:
[0007] Reed short fibers 10 - 30 parts, preferably 20 parts;
[0008] PBAT resin 60 - 80 parts, preferably 70 parts;
[0009] 5 to 10 parts of degradation aid, preferably 7 parts;
[0010] 1 to 2 parts of antioxidant, preferably 1.5 parts;
[0011] 1 to 3 parts of antibacterial agent, preferably 2 parts.
[0012] Furthermore, the diameter of the short reed fibers is 5 to 50 microns, and the aspect ratio is (5 to 100):1.
[0013] Furthermore, the melt index (190 °C / 2.16 kg) of the PBAT resin is 2 to 15 g / 10 min.
[0014] Furthermore, the degradation aid is one or a mixture of two or more of calcium carbonate, citric acid, and benzophenone–3.
[0015] Furthermore, the antioxidant is one or a mixture of two or more of vitamin E, epoxy cardanol, and antioxidant 1010.
[0016] Furthermore, the antibacterial agent is one or a mixture of two or more of chitosan, nano zinc oxide, and polyhexamethylene guanidine hydrochloride.
[0017] A preparation method of a short reed fiber / PBAT resin biodegradable blown film material, comprising the following steps:
[0018] Step (1), screening, extruding, and short-cutting reeds using mechanical equipment, removing reed leaves, reed flowers, and the outer skin of the reed stalks, and preparing short reed slices mainly composed of the reed stalks. The length of the reed slices is 0.5 to 2 cm, and the water content is 10% to 15%.
[0019] Step (2), steaming the reed slices in an alkali solution. After steaming, collecting the residue, washing it with clear water until neutral, centrifuging to remove impurities and fiber bundles that are not completely separated, and filtering and drying.
[0020] Furthermore, the feeding mass concentration of the reed slices in the alkali solution is 20% to 40%; the mass concentration of the alkali solution is 10 - 25%; the steaming temperature is 140 - 160 °C, the heating rate of the alkali solution is 5 - 10 °C / min, the heat preservation time is 2 to 3 hours, and the pressure during the steaming process is 0.8 to 1.2 MPa.
[0021] Step (3), uniformly mixing all the components obtained by drying in step (2) in a high-speed mixer at a mixing speed of 300 to 500 rpm for 6 to 10 minutes; after mixing, melting and extruding the mixture through a twin-screw extruder to prepare a biodegradable blown film composite material. Finally, using a blown film machine to blow-mold the biodegradable blown film composite pellet material to obtain the product.
[0022] Furthermore, the rotational speed of the twin-screw extruder is 50 - 250 revolutions per minute, the feeding speed is 3Hz - 20Hz, and the temperatures of each heating block of the twin-screw are as follows: the feeding section is 100 - 120°C, the compression section is 120 - 140°C, the homogenization section is 140 - 150°C, the exhaust section is 150 - 160°C, and the head is 160 - 170°C.
[0023] Furthermore, the extrusion temperature of the blown film machine is: the feeding section is 120 - 130°C, the compression section is 130 - 140°C, the metering section is 150 - 160°C, and the head is 160 - 170°C; the blow-up ratio is 2 - 4, the traction speed is 10 - 30m / min, and the air volume of the cooling air ring is 20 - 50m 3 / h, and the cooling air temperature is controlled at 15 - 30°C.
[0024] The beneficial effects of the present invention are as follows:
[0025] 1) The present invention combines mechanical processing methods with caustic soda cooking methods to prepare reed short fibers, which can not only avoid excessive pulverization of reeds, obtain short fibers with a controllable aspect ratio, but also remove impurities and increase the cellulose content in the reed short fibers.
[0026] 2) The present invention does not require additional interfacial modifiers. By virtue of the suitable aspect ratio of the reed short fibers, the entanglement and riveting effects with the PBAT resin are strengthened, that is, the interaction between the two is strengthened only by increasing the shear of the mixed melt and the physical entanglement between the reed short fibers and the PBAT resin. While effectively improving the performance of the composite material, the production cost of biodegradable film bag products is reduced. Description of the Drawings
[0027] Figure 1 It is a scanning electron microscope image of mechanically pulverized reed powder in the control experiment.
[0028] Figure 2 It is a scanning electron microscope image of the reed short fibers in Example 1. Detailed Embodiments
[0029] The technical solutions of the present invention are further described and illustrated below through specific embodiments in conjunction with the drawings.
[0030] Comparative Example 1
[0031] Compared with Example 1, reed powder was prepared by a simple mechanical pulverization method, and its particle aspect ratio was very small (see the attached Figure 1)。Mix 10 parts of reed powder with 60 parts of PBAT resin (melt index 2 g / 10 min), 5 parts of calcium carbonate, 1 part of antioxidant 1010 and 1 part of chitosan evenly in a high-speed mixer for 10 minutes at a mixing speed of 300 rpm; then, extrude and pelletize the mixture through a twin-screw extruder at a rotational speed of 50 rpm and a feeding speed of 3 Hz. The temperatures of each heating zone of the twin-screw are as follows: feeding section 100 °C, compression section 120 °C, homogenization section 140 °C, exhaust section 150 °C, and die head 160 °C. Blow film using the above pellets. The extrusion temperatures of the blow film machine are set as follows: feeding section 120 °C, compression section 130 °C, metering section 150 °C, and die head 160 °C; the blow-up ratio is 2, the traction speed is 10 m / min, and the air volume of the cooling air ring is 20 m 3 / h, and the cooling air temperature is 15 °C. The properties of the composite material and the blow film performance are shown in Table 1 in the appendix.
[0032] Example 1
[0033] Use mechanical equipment to screen, extrude and cut reeds short to prepare clean reed chips with a length of 0.5 cm and a water content of 10 wt%. In a 10-liter reaction kettle, prepare 5 liters of alkali solution with a concentration of 10 wt%, add reed chips according to a ratio of 20 wt%, heat to 140 °C at a heating rate of 5 °C / min, keep the temperature for 2 hours, and the pressure during the cooking process is 0.8 MPa. After the cooking is completed, collect the residue, wash it with clear water until neutral, centrifuge to remove impurities and fiber bundles that are not completely separated, filter and dry to obtain reed short fibers, see the appendix Figure 2 , analysis Figure 2 It can be seen that: The reed short fibers prepared by the present invention have a higher aspect ratio than the reed powder processed by mechanical pulverization in Example 1, which is beneficial to enhancing the modified PBAT resin.
[0034] Mix 10 parts of reed short fibers (diameter 5 microns, aspect ratio 5:1) with 60 parts of PBAT resin (melt index 2 g / 10 min), 5 parts of calcium carbonate, 1 part of antioxidant 1010 and 1 part of chitosan evenly in a high-speed mixer for 10 minutes at a mixing speed of 300 rpm; then, extrude and pelletize the mixture through a twin-screw extruder at a rotational speed of 50 rpm and a feeding speed of 3 Hz. The temperatures of each heating zone of the twin-screw are as follows: feeding section 100 °C, compression section 120 °C, homogenization section 140 °C, exhaust section 150 °C, and die head 160 °C. Blow film using the above pellets. The extrusion temperatures of the blow film machine are set as follows: feeding section 120 °C, compression section 130 °C, metering section 150 °C, and die head 160 °C; the blow-up ratio is 2, the traction speed is 10 m / min, and the air volume of the cooling air ring is 20 m 3 / h, and the cooling air temperature is 15 °C. The properties of the composite material and the blow film performance are shown in Table 1 in the appendix.
[0035] Example 2
[0036] Use mechanical equipment to screen, extrude and cut reeds short to prepare clean reed slices with a length of 2 cm and a water content of 15%. In a 10-liter reactor, prepare 5 liters of alkali solution with a concentration of 25%, add reed slices according to a 40% ratio, heat to 160 °C at a heating rate of 10 °C / min, keep warm for 3 hours, the pressure during the cooking process is 1.2 MPa. After the cooking is completed, collect the residue, wash it with clear water until neutral, centrifuge to remove impurities and incompletely separated fiber bundles, filter and dry to obtain reed short fibers.
[0037] Mix 30 parts of reed short fibers (diameter 50 microns, aspect ratio 100:1) with 80 parts of PBAT resin (melt index 15 g / 10 min), 10 parts of citric acid, 2 parts of vitamin E and 3 parts of nano-zinc oxide evenly in a high-speed mixer for 10 minutes, and the mixing speed is 500 rpm; then, extrude and granulate the mixture through a twin-screw extruder, the rotation speed is 250 rpm, the feeding speed is 20 Hz, and the temperatures of each heating block of the twin-screw are: feeding section 120 °C, compression section 140 °C, homogenization section 150 °C, exhaust section 160 °C, head 170 °C. Blow film with the above pellets, and the extrusion temperatures of the blown film machine are set as follows: feeding section 130 °C, compression section 140 °C, metering section 160 °C, head 170 °C; the blow-up ratio is 4, the traction speed is 30 m / min, and the air volume of the cooling air ring is 50 m 3 / h, and the cooling air temperature is 30 °C. The properties of the composite material and the blown film performance are shown in Table 1 in the appendix.
[0038] Example 3
[0039] Use mechanical equipment to screen, extrude and cut reeds short to prepare clean reed slices with a length of 1 cm and a water content of 12 wt%. In a 10-liter reactor, prepare 5 liters of alkali solution with a concentration of 15 wt%, add reed slices according to a 30 wt% ratio, heat to 150 °C at a heating rate of 8 °C / min, keep warm for 2.5 hours, the pressure during the cooking process is 1.0 MPa. After the cooking is completed, collect the residue, wash it with clear water until neutral, centrifuge to remove impurities and incompletely separated fiber bundles, filter and dry to obtain reed short fibers.
[0040] Mix 20 parts of reed short fibers (diameter 25 microns, aspect ratio 50:1), 70 parts of PBAT resin (melt index 10 g / 10 min), 8 parts of benzophenone–3, 1.5 parts of antioxidant epoxy cashew phenol, and 2 parts of antibacterial agent polyhexamethylene guanidine hydrochloride evenly in a high-speed mixer for 8 minutes at a mixing speed of 400 rpm. Then, extrude and pelletize the mixture through a twin-screw extruder at a rotation speed of 150 rpm, a feeding speed of 10 Hz. The temperatures of each heating zone of the twin-screw are as follows: feeding section 110 °C, compression section 130 °C, homogenization section 140 °C, exhaust section 160 °C, and die head 170 °C. Use the above pellets for blown film. The extrusion temperatures of the blown film machine are set as follows: feeding section 120 °C, compression section 130 °C, metering section 150 °C, and die head 160 °C; the blow-up ratio is 3, the traction speed is 20 m / min, the air volume of the cooling air ring is 25 m 3 / h, and the cooling air temperature is 20 °C. The properties of the composite material and the blown film are shown in Table 1 in the appendix.
[0041] Example 4
[0042] Use mechanical equipment to screen, extrude, and cut reeds to prepare clean reed chips with a length of 1.5 cm and a water content of 10 wt%. In a 10-liter reaction kettle, prepare 5 liters of lye with a concentration of 20 wt%, add reed chips according to a ratio of 25 wt%, heat to 145 °C at a heating rate of 6 °C / min, and hold for 2.5 hours. The pressure during the cooking process is 0.9 MPa. After the cooking is completed, collect the residue, wash it with clean water until neutral, centrifuge to remove impurities and fiber bundles that are not completely separated, filter and dry to obtain reed short fibers.
[0043] Mix 15 parts of reed short fibers (diameter 15 microns, aspect ratio 25:1), 65 parts of PBAT resin (melt index 5 g / 10 min), 7 parts of calcium carbonate, a mixture of 0.6 parts of antioxidant 1010 and 0.6 parts of antioxidant vitamin E, and 1.5 parts of antibacterial agent chitosan evenly in a high-speed mixer for 9 minutes at a mixing speed of 350 rpm. Then, extrude and pelletize the mixture through a twin-screw extruder at a rotation speed of 200 rpm, a feeding speed of 15 Hz. The temperatures of each heating zone of the twin-screw are as follows: feeding section 100 °C, compression section 120 °C, homogenization section 140 °C, exhaust section 150 °C, and die head 160 °C. Use the above pellets for blown film. The extrusion temperatures of the blown film machine are set as follows: feeding section 120 °C, compression section 130 °C, metering section 150 °C, and die head 160 °C; the blow-up ratio is 2.5, the traction speed is 25 m / min, the air volume of the cooling air ring is 35 m 3 / h, and the cooling air temperature is 20 °C. The properties of the composite material and the blown film are shown in Table 1 in the appendix.
[0044] Example 5
[0045] Use mechanical equipment to screen, extrude and cut reeds short to prepare clean reed chips with a length of 1.5 cm and a water content of 14 wt%. In a 10-liter reactor, prepare 5 liters of an alkali solution with a concentration of 20 wt%, add reed chips according to a ratio of 25 wt%, heat to 155 °C at a heating rate of 9 °C / min, hold for 2 hours, the pressure during the cooking process is 1.0 MPa. After the cooking is completed, collect the residue and wash it with clean water until neutral, centrifuge to remove impurities and fiber bundles that are not completely separated, filter and dry to obtain reed short fibers.
[0046] Mix 20 parts of reed short fibers (diameter 45 μm, aspect ratio 60:1), 65 parts of PBAT resin (melt index 10 g / 10 min), 10 parts of citric acid, 1 part of vitamin E and 1 part of an equimolar mixture of nano-zinc oxide and chitosan evenly in a high-speed mixer for 8 minutes at a mixing speed of 450 rpm; then, extrude and granulate the mixture through a twin-screw extruder at a rotational speed of 200 rpm and a feeding speed of 15 Hz. The temperatures of each heating zone of the twin-screw are as follows: feeding section 120 °C, compression section 130 °C, homogenization section 140 °C, exhaust section 150 °C, die head 160 °C. Blow film using the above pellets. The extrusion temperatures of the blow film machine are set as follows: feeding section: / 125 °C, compression section: 135 °C, metering section: 155 °C, die head: 165 °C; feeding section 130 °C, compression section 140 °C, metering section 150 °C, die head 160 °C; blow-up ratio is 4, draw speed is 20 m / min, the air volume of the cooling air ring is 40 m 3 / h, and the cooling air temperature is 25 °C. The properties of the composite material and the blow film performance are shown in Table 1 in the appendix.
[0047] Example 6
[0048] Use mechanical equipment to screen, extrude and cut reeds short to prepare clean reed chips with a length of 1.5 cm and a water content of 15 wt%. In a 10-liter reactor, prepare 5 liters of an alkali solution with a concentration of 15 wt%, add reed chips according to a ratio of 25 wt%, heat to 145 °C at a heating rate of 8 °C / min, hold for 1.5 hours, the pressure during the cooking process is 1.0 MPa. After the cooking is completed, collect the residue and wash it with clean water until neutral, centrifuge to remove impurities and fiber bundles that are not completely separated, filter and dry to obtain reed short fibers.
[0049] Mix 30 parts of reed short fibers (diameter 35 microns, aspect ratio 80:1), 70 parts of PBAT resin (melt index 12 g / 10 min), 10 parts of an equal proportion mixture of benzophenone–3 and calcium carbonate, 1 part of epoxy cashew phenol, and 1 part of polyhexamethylene guanidine hydrochloride in a high-speed mixer for 10 minutes at a mixing speed of 350 rpm. Then, granulate the mixture through a twin-screw melt extrusion process with a screw speed of 250 rpm, a feeding speed of 18 Hz, and the temperatures of each heating zone of the twin-screw being: feeding section 100 °C, compression section 120 °C, homogenization section 140 °C, degassing section 160 °C, and die head 170 °C. Use the above pellets for blown film extrusion, and set the extrusion temperatures of the blown film machine as follows: feeding section 130 °C, compression section 150 °C, metering section 160 °C, and die head 170 °C; the blow-up ratio is 3, the drawing speed is 25 m / min, the air volume of the cooling air ring is 45 m 3 / h, and the cooling air temperature is 20 °C. The properties of the composite material and the blown film are shown in Table 1 in the appendix. Table 1 shows the properties of the composite materials in the control experiment and Examples 1 to 6.
[0050] Table 1. Tensile property test table of PBAT resin and composite materials
[0051]
[0052] It can be seen from the analysis of Table 1 that by increasing the aspect ratio of the reed powder particles, the mechanical properties of the PBAT resin can be effectively improved. The reason is that the relatively high aspect ratio of the reed powder can improve the interaction mode and interaction force between the two phases through the interfacial entanglement and riveting with the resin molecules, playing a role in strengthening the interface.
[0053] The above embodiments only represent the implementation modes of the present invention, but should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention.
Claims
1. A reed short fiber / PBAT biodegradable blown film material, characterized in that, The raw materials for preparing the biodegradable blown film material include the following components in parts by weight: 10-30 parts of reed short fibers; 60-80 parts of PBAT resin; 5-10 parts of degradation aid; 1-2 parts of antioxidant; 1-3 parts of antibacterial agent.
2. The biodegradable blown film material made of reed short fibers / PBAT according to claim 1, characterized in that The components in parts by weight of the raw materials for preparing the biodegradable blown film material are preferably: 20 parts of reed short fibers; 70 parts of PBAT resin; 7 parts of degradation aid; 1.5 parts of antioxidant; 2 parts of antibacterial agent.
3. The biodegradable blown film material of reed short fiber / PBAT according to claim 1, characterized in that, The diameter of the reed short fibers is 5-50 microns, and the aspect ratio is (5-100):1; the melt index of the PBAT resin is 2-15 g / 10min.
4. The biodegradable blown film material of reed short fiber / PBAT according to claim 1, characterized in that The degradation aid is one or a mixture of two or more of calcium carbonate, citric acid, and benzophenone-3; the antioxidant is one or a mixture of two or more of vitamin E, epoxy cashew phenol, and antioxidant 1010; the antibacterial agent is one or a mixture of two or more of chitosan, nano-zinc oxide, and polyhexamethylene guanidine hydrochloride.
5. A preparation method of the reed short fiber / PBAT resin biodegradable blown film material according to any one of claims 1-4, characterized in that, It includes the following steps: Step (1), screening, extruding, and short-cutting reeds using mechanical equipment to remove reed leaves, reed flowers, and the outer skin of reed stalks, and preparing short reed slices mainly composed of reed stalks; Step (2), cooking the reed slices in an alkali solution. After cooking, collecting the residue, washing it with clear water until neutral, centrifuging to remove impurities and incompletely separated fiber bundles, and filtering and drying; Step (3), uniformly mixing all the components obtained by drying in step (2) in a high-speed mixer. After mixing, melting and extruding the mixture through a twin-screw extruder to granulate, preparing a biodegradable blown film composite material. Finally, using a blown film machine to blow-mold the biodegradable blown film composite pellets to obtain the product.
6. The preparation method of a reed short fiber / PBAT resin biodegradable blown film material according to claim 5, characterized in that, In step (1), the length of the reed slices is 0.5-2 cm, and the water content is 10%-15%.
7. The preparation method of a reed short fiber / PBAT resin biodegradable blown film material according to claim 5, characterized in that, In step (2), the feeding mass concentration of the reed slices in the alkali solution is 20%-40%; the mass concentration of the alkali solution is 10-25%; the cooking temperature is 140-160°C, the heating rate of the alkali solution is 5-10°C / min, the heat preservation time is 2-3 hours, and the pressure during the cooking process is 0.8-1.2 MPa.
8. The preparation method of a reed short fiber / PBAT resin biodegradable blown film material according to claim 5, characterized in that In step (3), the rotation speed of the twin-screw extruder is 50-250 revolutions per minute, the feeding speed is 3 Hz-20 Hz, and the temperatures of each heating block of the twin-screw are respectively: the feeding section is 100-120°C, the compression section is 120-140°C, the homogenization section is 140-150°C, the exhaust section is 150-160°C, and the head is 160-170°C.
9. The preparation method of a reed short fiber / PBAT resin biodegradable blown film material according to claim 5, characterized in that, In the step (3), the extrusion temperature of the blown film machine is as follows: the feeding section is 120 - 130 °C, the compression section is 130 - 140 °C, the metering section is 150 - 160 °C, and the die head is 160 - 170 °C; the blow-up ratio is 2 - 4, the traction speed is 10 - 30 m / min, and the air volume of the cooling air ring is 20 - 50 m 3 / h, and the cooling air temperature is controlled at 15 - 30 °C.
10. The preparation method of a reed short fiber / PBAT resin biodegradable blown film material according to claim 5, characterized in that, In step (3), the mixing speed of the high-speed mixer is 300-500 rpm, and the mixing time is 6-10 minutes.