Potato starch residue reinforced PBAT degradable injection molding material and preparation method and application thereof

Abstract

The application relates to the technical field of plastic production, in particular to a potato starch residue reinforced PBAT degradable injection molding material and a preparation method and application thereof. After a silane coupling agent is used to modify potato starch residue, the modified potato starch residue and thermoplastic biodegradable plastic (PBAT) are uniformly mixed according to a weight ratio of (1:9) to (6:4), and then melt blending is carried out, and the potato starch residue reinforced PBAT degradable injection molding material is obtained after cooling. When the weight ratio of the pretreated potato starch residue and the PBAT is 6:4, the tensile strength of the prepared sample can reach 14.9 MPa, a large amount of potato starch residue is added to obtain high-performance injection molding material, and resource recycling is realized; through differential scanning calorimetry (DSC) analysis, the glass transition temperature and the melting temperature of the degradable injection molding material are higher than those of pure PBAT, which indicates that the material has good thermal stability.

Description

Technical Field

[0001] This invention relates to the field of plastic production technology, specifically to a potato starch residue-reinforced PBAT biodegradable injection molding material, its preparation method, and its application. Background Technology

[0002] Biodegradable plastics are materials with excellent performance characteristics that can be completely decomposed by environmental microorganisms after disposal. With the increasing severity of plastic pollution, the research and application of biodegradable plastic materials are receiving more and more attention. Thermoplastic biodegradable plastic PBAT, as a type of biodegradable plastic, has been widely studied due to its good processing properties and biodegradability. Meanwhile, natural polymers such as cellulose and starch are abundant in nature, inexpensive, and renewable. Biopolymer materials prepared from these materials have good biocompatibility, can be completely degraded, and are safe and non-toxic. They have gained attention from various countries due to their dual significance of fully utilizing natural renewable resources and environmental governance. However, most of them lack thermoplasticity, are difficult to mold and process, and have poor water resistance, which limits their application.

[0003] In the prior art, Chinese invention patent application number 202110561417.5 discloses a method for producing biodegradable plastics from sugarcane bagasse, including the following steps: S1 Take the following raw materials in parts by weight: 60-100 parts modified sugarcane bagasse, 20-30 parts filler, 0.5-1 part C5 petroleum resin, 2-6 parts polyacrylate, 3-6 parts plasticizer, 2-4 parts coupling agent, and 0.1-0.3 parts dispersant; S2 Raw material pretreatment: Put the above raw materials into a high-speed mixer and mix evenly, stirring at a speed of 850-1500 r / min for 15-25 min; S3 Melt-blend the mixture to obtain a uniformly mixed blend; S4 Add the blend obtained in the previous step to a twin-screw extruder, extrude and granulate to obtain the biodegradable plastic product. The tensile strength of the obtained biodegradable plastic product is 11.53-12.93 MPa.

[0004] Potato starch residue is a byproduct of potato processing, mainly composed of starch, cellulose, hemicellulose, pectin, protein, free amino acids, minerals, and fats. It has potential reinforcing properties; however, fresh potato residue can have a moisture content exceeding 90%, giving it a slurry-like consistency. Furthermore, the moisture binds to the fiber and pectin, making moisture removal difficult and drying costs high. Additionally, due to the presence of various microorganisms, potato residue is prone to spoilage and is difficult to store and transport, increasing the challenges of development and reuse. Given my country's large potato production and the correspondingly large amount of potato starch residue generated during processing, utilizing this residue in the production of biodegradable plastics to create biodegradable plastics with excellent mechanical properties and thermal stability, while simultaneously achieving resource recycling, is of great significance. Summary of the Invention

[0005] Based on this, the present invention provides a potato starch residue-reinforced PBAT biodegradable injection molding material and its preparation method, so as to apply this part of the potato starch residue to the production of biodegradable plastics, to prepare biodegradable plastics with excellent mechanical properties and thermal stability, while realizing the recycling of resources.

[0006] The technical solution to the above-mentioned technical problems in this application is as follows:

[0007] A method for preparing a biodegradable PBAT injection molding material reinforced with potato starch residue includes the following steps:

[0008] S10. Dry, crush and sieve the potato starch residue to obtain pretreated potato starch residue;

[0009] S20. Add a silane coupling agent solution to the pretreated potato starch residue, stir evenly, and then dry to obtain the modified potato starch residue.

[0010] S30. The modified potato starch residue and PBAT are mixed evenly at a weight ratio of (1:9) to (6:4) to obtain a mixture;

[0011] S40. The mixture is melt-blended at a temperature of 100 to 135°C for 10 to 20 minutes and then cooled to obtain potato starch residue-reinforced PBAT biodegradable injection molding material.

[0012] Preferably, in the above preparation method, in step S10, the potato starch residue is sieved through a mesh size of 50 to 150.

[0013] Preferably, in the above preparation method, the preparation method of the silane coupling agent solution in step S20 is as follows:

[0014] A silane coupling agent is added to a mixed solution of anhydrous ethanol and distilled water to obtain the silane coupling agent solution; wherein the volume ratio of anhydrous ethanol to distilled water in the mixed solution of anhydrous ethanol and distilled water is (8 to 10):1.

[0015] Preferably, in the above preparation method, in step S20, the weight ratio of the pretreated potato starch residue to the silane coupling agent in the silane coupling agent solution is (15 to 20):1.

[0016] Preferably, in the above preparation method, the silane coupling agent is 3-aminopropyltriethoxysilane.

[0017] Preferably, in the above preparation method, in step S30, the weight ratio of the pretreated potato starch residue to the PBAT is (5:5) to (6:4).

[0018] A biodegradable injection molding material reinforced with potato starch residue (PBAT) is prepared by the above-mentioned method for preparing biodegradable injection molding material reinforced with potato starch residue (PBAT).

[0019] Application of a potato starch residue-reinforced PBAT biodegradable injection molding material as described above in the preparation of biodegradable plastic products.

[0020] The above-described solution adopted in this application has at least the following beneficial effects:

[0021] The method for preparing potato starch residue-reinforced PBAT biodegradable injection molding material (hereinafter referred to as biodegradable injection molding material) provided in this application involves first drying, pulverizing, and sieving potato starch residue to obtain pretreated potato starch residue; then adding a silane coupling agent solution to the pretreated potato starch residue, stirring evenly, and drying to obtain modified potato starch residue; then mixing the modified potato starch residue with thermoplastic biodegradable plastic (PBAT) at a weight ratio of (1:9) to (6:4) evenly to obtain a mixture; finally, melt-blending the mixture at a blending temperature controlled at 100 to 135°C for 10 to 20 minutes and then cooling to obtain potato starch residue-reinforced PBAT biodegradable injection molding material. When the weight ratio of pretreated potato starch residue to PBAT is 6:4, the tensile strength of the prepared biodegradable injection molding material sample can reach 14.9 MPa, exhibiting good mechanical properties. While obtaining a high-performance injection molding material, a large amount of potato starch residue is added, realizing the recycling of resources. Differential scanning calorimetry (DSC) analysis shows that the glass transition temperature and melting temperature of the biodegradable injection molding material of this application are higher than those of pure PBAT, indicating that the material has good thermal stability. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a bar chart showing the tensile strength of biodegradable injection molded materials.

[0024] Figure 2 This is a graph showing the cooling process of a biodegradable injection molding material after its first heating.

[0025] Figure 3 This is a graph showing the second temperature rise of a biodegradable injection molded material after heating and cooling. Detailed Implementation

[0026] It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. The technical solutions of the present invention will be further described below with reference to the accompanying drawings of the embodiments of the present invention. The present invention is not limited to the following specific embodiments.

[0027] It should be understood that the same or similar reference numerals in the accompanying drawings of the embodiments correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "front," "rear," "left," "right," "top," and "bottom" indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, they are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms describing positional relationships in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0028] In one specific embodiment, a method for preparing a biodegradable PBAT injection molding material reinforced with potato starch residue includes the following steps:

[0029] S10. Dry, crush and sieve the potato starch residue to obtain pretreated potato starch residue;

[0030] Potato starch residue is a byproduct of potato processing, mainly composed of starch, cellulose, hemicellulose, pectin, protein, free amino acids, minerals, and fats. It has potential enhancing properties; however, fresh potato residue can have a moisture content exceeding 90%, so it needs to be dried before use. Furthermore, because potato starch residue particles vary in size, direct use can affect the morphology and properties of the resulting biodegradable injection molding materials. Therefore, the dried potato starch residue should be pulverized and then sieved, preferably with a sieve mesh size of 50 to 150 mesh.

[0031] S20. A silane coupling agent solution is added to the pretreated potato starch residue, stirred evenly, and then dried to obtain modified potato starch residue. The silane coupling agent solution is prepared by adding the silane coupling agent to a mixed solution of anhydrous ethanol and distilled water. The volume ratio of the anhydrous ethanol to the distilled water in the mixed solution is (8 to 10):1. In this step, the mixed solution of anhydrous ethanol and distilled water mainly acts as a solvent, that is, it is used to dissolve the silane coupling agent. The amount of silane coupling agent solution added should be such that the pretreated potato starch residue can be evenly mixed with the silane coupling agent, and the weight ratio of the pretreated potato starch residue to the silane coupling agent in the silane coupling agent solution is (15 to 20):1. By using silane coupling agents, a "molecular bridge" can be built between the interface of inorganic and organic substances, connecting two materials with vastly different properties to improve the performance of composite materials and increase adhesive strength. The preferred silane coupling agent in this application is 3-aminopropyltriethoxysilane (KH550), also known as γ-aminopropyltriethoxysilane, 3-aminopropyltriethoxysilane, or 3-APTS. Its chemical formula is NH2CH2CH2CH2Si(OC2H5)3, and it is an amino-functionalized silane, exhibiting alkalinity. It is a colorless or slightly yellow transparent liquid with high versatility. KH550 contains two different active groups—amino and oxygen—used to couple organic polymers and inorganic fillers, enhancing their adhesion and improving the mechanical, electrical, water-resistant, and anti-aging properties of the product.

[0032] S30. The modified potato starch residue and PBAT are mixed evenly at a weight ratio of (1:9) to (6:4) to obtain a mixture; preferably, the weight ratio of the pretreated potato starch residue to PBAT is (5:5) to (6:4). Experiments show that as the amount of pretreated potato starch residue added increases, the tensile strength of the sample first decreases and then increases, with an average value of 13.33 MPa, which is still higher than the tensile strength of biodegradable plastics produced from sugarcane bagasse in the background technology. However, when the mass ratio of pretreated potato starch residue to PBAT is 7:3, the two cannot be mixed and melted together, which cannot meet the preparation process requirements. When the weight ratio of pretreated potato starch residue to PBAT is 6:4, the tensile strength of the biodegradable injection molding material obtained after injection molding can reach 14.9 MPa, which has good mechanical properties. While obtaining a high-performance injection molding material, a large amount of potato starch residue is added, realizing the recycling of resources.

[0033] S40. The mixture is melt-blended at a temperature controlled between 100 and 135°C for 10 to 20 minutes, and then cooled to obtain a potato starch residue-reinforced PBAT biodegradable injection molding material. Specifically, the mixture is melt-blended in an internal mixer for 10 to 20 minutes, with the blending temperature controlled at 135°C in zone one and 100°C in zone two. The blended material is then cooled to obtain the potato starch residue-reinforced PBAT biodegradable injection molding material.

[0034] In another specific embodiment of this application, a potato starch residue-reinforced PBAT biodegradable injection molding material is prepared by the above-mentioned method for preparing potato starch residue-reinforced PBAT biodegradable injection molding material.

[0035] In another specific embodiment of this application, a potato starch residue-reinforced PBAT biodegradable injection molding material is used in the preparation of biodegradable plastic products.

[0036] It is worth noting that the process temperature and process time designed in the above embodiments are all temperatures or times used in the experiment. Any reasonable adjustments made by those skilled in the art based on the process temperature and process time provided by this invention, within the error range, should be included within the protection scope of this invention.

[0037] The following specific experimental examples further illustrate the technical solution and technical effects of the present invention.

[0038] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art.

[0039] 1. Main reagents

[0040] It should be noted that in the embodiments of the present invention, all reagents and solvents are commercially available and can be used without further purification.

[0041] 2. Blank example

[0042] The PBAT material was directly injection molded at a heating temperature of 225℃, a pressure of 0.5MPa, and a holding time of 15s to prepare the required sample.

[0043] 3. Comparative Example

[0044] Take 10.56 parts of potato starch residue, dry and pulverize it, sieve it through a 100-mesh sieve, and then mix it with 100 parts of PBAT. Melt-blend the mixture in an internal mixer for 15 minutes, with the blending temperature controlled at 135℃ in zone one and 100℃ in zone two. Cool the blended material to obtain PBAT biodegradable injection molding material. Inject the PBAT biodegradable injection molding material into samples with an injection heating temperature of 225℃, a pressure of 0.5MPa, and a holding time of 15s.

[0045] 4. Example 1: Exploring the effect of modified potato starch residue on the properties of biodegradable injection molding materials

[0046] 10.56 parts of potato starch residue were dried and pulverized, and then sieved through a 100-mesh sieve to obtain pretreated potato starch residue. A silane coupling agent solution was added to the pretreated potato starch residue, stirred evenly, and then dried. The silane coupling agent solution contained 0.56 parts of silane coupling agent KH550, 17.3 ml of anhydrous ethanol, and 1.9 ml of distilled water. The pretreated potato starch residue was then mixed with 100 parts of PBAT. The mixture was melt-blended in an internal mixer for 15 minutes, with the blending temperature controlled at 135℃ in zone one and 100℃ in zone two. The blended material was cooled to obtain PBAT biodegradable injection molding material. The PBAT biodegradable injection molding material was injection molded at an injection heating temperature of 225℃, a pressure of 0.5 MPa, and a holding time of 15 seconds to prepare the required sample, labeled as Sample 1.

[0047] Mechanical properties were tested on the samples from the blank example, comparative example, and Example 1, and the test results are as follows:

[0048] Table 1 Tensile strength of blank example, comparative example and Example 1

[0049] Blank example 22.5 Comparative Example 12.1 Sample 1 17.5

[0050] As shown in Table 1, when unmodified potato starch residue is directly added to PBAT material, the tensile strength and impact strength of the resulting biodegradable injection molded sample (i.e., the comparative sample) are significantly reduced. This indicates that potato starch residue cannot be directly used in the preparation of biodegradable injection molded materials. In Example 1, potato starch residue was modified with a silane coupling agent solution. The modified potato starch residue and PBAT were used to prepare a biodegradable injection molded material. Mechanical property tests show that the tensile strength of Sample 1 is 17.5 MPa, significantly higher than the comparative sample. It is also 4.57 to 5.97 MPa higher than the tensile strength of biodegradable plastics produced from sugarcane bagasse in the background technology, representing an improvement rate of 35.34% to 51.78%.

[0051] 5. Example 2: Exploring the effect of modified potato starch residue addition amount on the properties of biodegradable injection molding materials

[0052] The weight proportions of potato starch residue shown in Table 2 are taken, dried, pulverized, and sieved through a 100-mesh sieve to obtain pretreated potato starch residue. A silane coupling agent solution is added to the pretreated potato starch residue, stirred evenly, and then dried. The contents of the silane coupling agent solution containing silane coupling agent KH550, anhydrous ethanol, and distilled water are shown in Table 2. Then, it is mixed with the weight proportions of PBAT shown in Table 2. The mixture is melt-blended in a mixer for 15 minutes, with the blending temperature controlled at 135℃ in zone one and 100℃ in zone two. The blended material is cooled to obtain PBAT biodegradable injection molding material. The PBAT biodegradable injection molding material is injection molded at an injection heating temperature of 225℃, a pressure of 0.5MPa, and a holding time of 15s to prepare the required samples, labeled as Sample 2 to Sample 7.

[0053]

[0054] Table 2. Amounts of each raw material used in the sample of Example 2

[0055] Note: Pretreated potato starch residue content = weight of pretreated potato starch residue / (weight of pretreated potato starch residue + weight of PBAT) × 100%.

[0056] The mechanical properties of the sample from Example 2 above were tested, and the results are as follows:

[0057] Table 3 Tensile strength of Example 2

[0058]

[0059]

[0060] Please refer to Table 3 and combine it with... Figure 1With increasing amounts of pretreated potato starch residue, the tensile strength of the samples initially decreased and then increased, with an average value of 13.33 MPa, still higher than the tensile strength of biodegradable plastics produced from sugarcane bagasse in the background technology. Sample 6 had a tensile strength of 14.9 MPa, significantly higher than the control sample, and also 1.97 to 3.37 MPa higher than the tensile strength of biodegradable plastics produced from sugarcane bagasse in the background technology, representing an improvement rate of 15.23% to 29.22%. It should be noted that when the mass ratio of pretreated potato starch residue to PBAT is 7:3, the two cannot be mixed and melted together, failing to meet the requirements of the preparation process.

[0061] 6. Thermal stability test

[0062] The thermal stability of the samples was evaluated using differential scanning calorimetry (DSC). The test method for DSC in ISO 11357 was followed, and the experimental data were obtained using the DSC Q1000 from TA Instruments.

[0063] Please see Figure 2 and Figure 3 The glass transition temperature (Tg) of pure PBAT is 42.48℃. After adding potato starch residue, its Tg increases significantly, reaching a maximum of 47.53℃. The glass transition temperature of a material is related to the temperature resistance of the product; the higher the Tg, the better the temperature resistance of the processed product. The increase in Tg is mainly due to the incorporation of modified potato starch residue into the flexible PBAT molecular chains. The two undergo cross-linking, and the resulting network structure increases the rigidity of the composite material's molecular chains, thereby increasing the glass transition temperature.

[0064] The melting temperature of pure PBAT material is 120.83℃, while the addition of potato starch residue directly increases the melting temperature of the sample to 126.17℃. This is mainly due to the hydrogen bonds formed by the interaction of free -OH groups in the modified potato starch residue with the PBAT molecular chains, which increases the enthalpy and thus raises the melting temperature.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a biodegradable injection molding material reinforced with potato starch residue (PBAT), characterized in that, Includes the following steps: S10. Dry, crush and sieve the potato starch residue to obtain pretreated potato starch residue; S20. Add a silane coupling agent solution to the pretreated potato starch residue, stir evenly, and then dry to obtain the modified potato starch residue. The weight ratio of the pretreated potato starch residue to the silane coupling agent in the silane coupling agent solution is (15 to 20):

1. S30. The modified potato starch residue and PBAT are mixed evenly at a weight ratio of 6:4 to obtain a mixture; S40. The mixture is melt-blended at a temperature of 100 to 135 °C for 10 to 20 min and then cooled to obtain potato starch residue reinforced PBAT biodegradable injection molding material.

2. The preparation method according to claim 1, characterized in that, In step S10, the potato starch residue is sieved through a mesh size of 50 to 150.

3. The preparation method according to claim 1, characterized in that, In step S20, the silane coupling agent solution is prepared as follows: A silane coupling agent is added to a mixed solution of anhydrous ethanol and distilled water to obtain the silane coupling agent solution; wherein the volume ratio of anhydrous ethanol to distilled water in the mixed solution of anhydrous ethanol and distilled water is (8 to 10):

1.

4. The preparation method according to claim 3, characterized in that, The amount of the silane coupling agent added per liter of the mixture of anhydrous ethanol and distilled water is 25 to 35 parts.

5. The preparation method according to claim 3, characterized in that, The silane coupling agent is 3-aminopropyltriethoxysilane.

6. A biodegradable injection molding material of PBAT reinforced with potato starch residue, characterized in that, The material is prepared by the method for preparing potato starch residue-reinforced PBAT biodegradable injection molding material according to any one of claims 1 to 5.

7. An application of a potato starch residue-reinforced PBAT biodegradable injection molding material, characterized in that, The application of the biodegradable injection molding material as described in claim 6 in plastic production.

Images