A fully degradable PLA composite material with ceramic properties and a preparation method thereof

Abstract

The application relates to a fully-degradable PLA composite material with ceramic characteristics and a preparation method thereof, which is composed of the following raw materials in percentage by weight: PLA 25-45%, PBS 5-13%, a filler 48-60%, and the balance of processing aids; the filler is obtained by modifying an inorganic filler by a modifier; the modifier comprises methyl hydrogen polysilazane and a bio-based maleic anhydride graft; the bio-based maleic anhydride graft is composed of one or more of the following: maleic anhydride grafted polybutylene adipate terephthalate, maleic anhydride grafted polyvinyl alcohol and octenyl succinic anhydride modified starch; through the synergistic effect of the inorganic components of the filler, the ratio of PLA / PBS and the modifier, the material matches the use requirements of ceramic flying discs in key indicators, and all components have bio-based or degradable characteristics, realizing the dual goals of "ceramic performance bionics" and "environmental protection controllable degradation".

Description

Technical Field

[0001] This application relates to the field of composite materials, and more specifically, to a fully degradable PLA composite material with ceramic properties and a method for preparing the same. Background Technology

[0002] In shooting sports, skeet targets are the core objective, and their material properties directly affect the shooting experience and environmental friendliness. Currently, the mainstream ceramic skeet targets are mainly made from a mixture of asphalt, stone powder, and gypsum, pressed together. Due to their excellent brittleness, these ceramic skeet targets quickly shatter into small fragments upon impact with a bullet. This facilitates clear judgment of the hit by referees and avoids large fragments causing physical injury to the venue and personnel, thus maintaining their dominant position in the shooting field for a long time.

[0003] However, the materials used in ceramic flying saucers pose significant environmental risks: the asphalt they contain is a non-degradable polymer compound that is difficult for microorganisms to break down in the natural environment and will remain in the soil or water for a long time, gradually accumulating and causing persistent pollution; at the same time, although inorganic components such as stone powder and gypsum are harmless in themselves, the fragment structure formed when combined with asphalt is stable and easily creates "white pollution" around the shooting range, disrupting the natural cycle of the ecological environment and seriously conflicting with the global advocacy of green development.

[0004] In response to environmental protection needs, modern skeet shooting competitions have begun to promote skeet shooting made of biodegradable and environmentally friendly materials, aiming to reduce the negative environmental impact of target use from the source. However, existing biodegradable materials face multiple performance bottlenecks in practical applications: On the one hand, their hardness, density, brittleness, and mass uniformity cannot meet the standards of ceramic skeet shooting—insufficient hardness leads to excessively large fragments, affecting hit judgment; density deviation causes unstable flight trajectories, interfering with shooting accuracy; and imbalance in brittleness may result in excessive fragmentation (generating dust) or incomplete fragmentation (forming large pieces of debris). On the other hand, existing environmentally friendly materials have poor chemical stability, and the degradation process is difficult to control: during storage, they are easily affected by temperature and humidity, leading to premature degradation, deformation, and reduced strength, rendering the skeet unusable; after use, if the degradation rate is too slow, it will still cause a short-term environmental burden, while if the degradation is too fast, it may be damaged by natural aging before being hit, seriously affecting the normal development of the sport.

[0005] Therefore, developing a composite material that can accurately mimic the key performance characteristics of a ceramic flying saucer, while also possessing fully degradable properties and a controllable degradation process, has become a core technological requirement for resolving the contradiction between the environmental friendliness and practicality of current shooting targets. Summary of the Invention

[0006] In order to achieve the key performance characteristics of a precise biomimetic ceramic flying saucer, and to have the characteristics of full degradation and controllable degradation process, this application provides a fully degradable PLA composite material with ceramic properties and its preparation method.

[0007] Firstly, a fully degradable PLA composite material with ceramic properties is composed of the following raw materials by weight percentage:

[0008] PLA: 25-45%

[0009] PBS: 5-13%

[0010] Filler: 48-60%

[0011] The remainder is processing aids;

[0012] The filler is obtained by modifying inorganic fillers with a modifier;

[0013] The modifier comprises methyl hydrogen polysilazane and bio-based maleic anhydride grafts;

[0014] The bio-based maleic anhydride graft is composed of one or more of the following: maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch.

[0015] By employing the above technical solutions, the proportions of PLA, PBS, fillers, and processing aids are precisely controlled, and combined with a specific modification system, synergistic effects among the components are achieved. Furthermore, the addition of PBS effectively improves the material's toughness and the temperature of PLA, preventing product deformation during packaging and transportation. Methyl hydrogen-containing polysilazane forms a dense siloxane layer on the surface of the inorganic filler, enhancing the interfacial compatibility between the filler and the resin matrix and reducing stress concentration. The polar groups of the bio-based maleic anhydride graft form hydrogen bonds or covalent bonds with the hydroxyl / ester groups of PLA and PBS, strengthening interfacial bonding and ensuring uniform dispersion of the inorganic filler in the matrix. This improves the material's hardness and density, optimizes impact strength, and precisely mimics the hard and brittle characteristics of bioceramics.

[0016] Meanwhile, the natural components in the bio-based maleic anhydride grafts accelerate the degradation process of the material in the natural environment, while the siloxane layer formed by methyl hydrogen-containing polysilazane delays premature degradation in the unused state, achieving controllability of the degradation process and balancing structural stability during the target's use phase with rapid degradation after disposal. Furthermore, the synergistic effect of the inorganic components of the filler, the PLA / PBS ratio, and the modifiers enables the material to meet the usage requirements of ceramic flying saucers in key indicators. Through the bio-based or biodegradable characteristics of all components, the dual goals of "bionic ceramic performance" and "environmentally friendly and controllable degradation" are achieved.

[0017] Preferably, the processing aid is one or more of antioxidants, lubricants, and fluorescent powders.

[0018] By adopting the above technical solution, one or more of antioxidants, lubricants, and phosphors can be added to fully degradable PLA composite materials with ceramic properties as processing aids to further improve the material's antioxidant properties and processing fluidity. In addition, the material can also have fluorescent properties and can work synergistically with other components to achieve precise biomimicry of ceramic flying saucers in terms of mechanical properties, while taking into account both fully degradable characteristics and controllable degradation.

[0019] Preferably, the antioxidant is antioxidant 1010 and / or antioxidant 168.

[0020] By adopting the above technical solution, in the fully degradable PLA composite material with ceramic properties composed of PLA, PBS, fillers modified by specific modifiers, and processing aids, antioxidant 1010 and / or antioxidant 168 are selected as antioxidants. As part of the processing aids, they help to improve the antioxidant performance of the material, making the material more stable in use and storage. Combined with other components, they precisely mimic the key performance of the ceramic flying saucer, achieving fully degradable characteristics and controllable degradation process.

[0021] Preferably, the lubricant is EBS and / or silicone oil.

[0022] By adopting the above technical solution, in the fully degradable PLA composite material with ceramic properties composed of PLA, PBS, modified filler and processing aid, when the processing aid contains a lubricant and the lubricant is EBS and / or silicone oil, it can play a lubricating role in the material preparation process, which is conducive to the uniform mixing and melting of each raw material, ensuring the smooth preparation of the composite material. At the same time, in conjunction with other components, the composite material achieves the comprehensive advantages of precise biomimetic ceramic flying saucer key performance, fully degradable characteristics and controllable degradation.

[0023] Preferably, the inorganic filler is barium sulfate and / or talc.

[0024] By adopting the above technical solution, using barium sulfate and / or talc as inorganic fillers, and modifying them with a modifier before adding them as fillers to a blend matrix composed of PLA and PBS, the rigidity and density of the material can be improved, resulting in a Shore hardness of >81D and a density controlled between 1.93-2.31 g / cm³. 3 This design matches the rigidity and mass characteristics of ceramic flying saucers; it can also be combined with the matrix toughness of PLA / PBS to allow the material's impact strength to be controlled between 2-4 kJ / m. 2The hard and brittle range meets the target assessment requirement of "breaking into small pieces" during shooting, achieving precise biomimicry of ceramic mechanical properties; at the same time, the bio-based or biodegradable characteristics of all components realize the dual goals of "ceramic performance biomimicry" and "environmentally friendly and controllable degradation", providing a solution for shooting targets that takes into account both practicality and sustainability.

[0025] Preferably, the amount of the modifier is 8-20 wt% of the filler.

[0026] By adopting the above technical solutions, the amount of modifier is precisely controlled at 8-20 wt% of the filler. Combined with the proportions of PLA, PBS, fillers, and processing aids, and a specific modification system, synergistic effects among the components are achieved. This enables interfacial synergy between the matrix resin and the modified filler, improving the material's hardness, density, impact strength, and other properties, and precisely mimicking the hard and brittle characteristics of ceramics. It also achieves controllable synergy in degradation performance, solving the pain point of traditional environmentally friendly materials where "stability and degradability are difficult to balance." Finally, it achieves a balanced performance of multiple components, realizing the dual goals of "bionic ceramic performance" and "environmentally friendly and controllable degradation."

[0027] Preferably, the weight ratio of the methyl hydrogen-containing polysilazane to the bio-based maleic anhydride graft is 1:(1-3).

[0028] By employing the above technical solution, and combining specific proportions of PLA, PBS, fillers, and processing aids with a specific weight ratio of methyl hydrogen-containing polysilazane and bio-based maleic anhydride grafts, a synergistic effect can be achieved among the components. Methyl hydrogen-containing polysilazane forms a dense siloxane layer on the surface of the inorganic filler, enhancing the interfacial compatibility between the filler and the resin matrix and reducing stress concentration. The polar groups of the bio-based maleic anhydride grafts can form hydrogen bonds or covalent bonds with the hydroxyl / ester groups of PLA and PBS, further strengthening the interfacial bonding force. This dual modification mechanism ensures that the inorganic filler is uniformly dispersed in the matrix, improving the material's hardness and density, optimizing impact strength, and precisely mimicking the hard and brittle characteristics of ceramics. Simultaneously, the natural components in the bio-based maleic anhydride grafts can accelerate the material's degradation process in the natural environment, while the siloxane layer formed by methyl hydrogen-containing polysilazane can delay premature degradation in the unused state, achieving controllable degradation and balancing the dual goals of material performance and environmentally friendly degradation.

[0029] Preferably, the bio-based maleic anhydride graft is composed of one or more of maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch in a weight ratio of 1:(0.5-1):(1-3).

[0030] By adopting the above technical solution, the weight ratio of each component in the bio-based maleic anhydride graft is precisely controlled. Combined with the dosage ratio of PLA, PBS, filler, and processing aids in claim 1, as well as the modifying effect of the modifier on the filler, the polar groups of the bio-based maleic anhydride graft form hydrogen bonds or covalent bonds with the hydroxyl / ester groups of PLA and PBS, strengthening the interfacial bonding force, allowing the inorganic filler to be uniformly dispersed in the matrix, improving the material's hardness and density, optimizing impact strength, and precisely mimicking the hard and brittle characteristics of ceramics. At the same time, the natural components in the bio-based maleic anhydride graft can act as degradation promoters, forming synergistic hydrolysis sites with the ester bonds of PLA / PBS, accelerating the degradation process of the material in the natural environment. Combined with the "barrier effect" of the siloxane layer formed by methyl hydrogen-containing polysilazane, the degradation process is controllable, solving the pain point of "difficulty in balancing stability and degradability" in traditional environmentally friendly materials. This allows the material to match the usage requirements of ceramic flying saucers in key indicators, achieving the dual goals of "bionic ceramic performance" and "environmentally friendly and controllable degradation".

[0031] Preferably, the filler is prepared by the following method:

[0032] Methyl hydrogen-containing polysilazane was dispersed in ethyl acetate to obtain a methyl hydrogen-containing polysilazane solution;

[0033] Inorganic filler was mixed evenly with methyl hydrogen polysilazane solution, dried, and ethyl acetate was removed to obtain mixture A; bio-based maleic anhydride graft was heated and melted into a fluid state, then added to mixture A, stirred evenly, cooled, and pulverized to obtain filler.

[0034] By employing the above technical solutions, the gradient modification of the filler preparation method constructs a compatible interface, enhancing the interaction with PLA / PBS. The dense siloxane transition layer formed in the first step retains the rigidity of the inorganic filler, adjusts the compatibility with PLA, and provides reaction sites. The polar-nonpolar gradient interface layer formed in the second step achieves "two-phase anchoring" between the filler and the PLA / PBS blend matrix, improving the uniformity of the material's mechanical properties. The synergistic process endows the material with the core properties of biomimetic ceramics, ensuring uniform dispersion of the inorganic filler in the matrix, stabilizing the Shore hardness of the composite material at >81D, and controlling the density at 1.93-2.31 g / cm³. 3 Impact strength is controlled between 2-4 kJ / m 2 The hard and brittle range; the structured design achieves controllable synergy in degradation performance. The siloxane layer formed by methyl hydrogen-containing polysilazane delays the initial erosion of the matrix by moisture and microorganisms, so that the stability rate of the unused target remains above 90% in the natural environment. The natural components in the bio-based maleic anhydride graft accelerate the hydrolysis and biodegradation of PLA / PBS ester bonds after the material is discarded, realizing a controllable process of "stability during use - rapid degradation after disposal".

[0035] Secondly, a method for preparing a fully degradable PLA composite material with ceramic properties includes the following steps:

[0036] Weigh PLA, PBS, filler, and processing aids according to their weight, mix them evenly, melt and mix them evenly, and then cool them to obtain a fully degradable PLA composite material.

[0037] By employing the above-mentioned technical solution, PLA, PBS, fillers, and processing aids are weighed, mixed in proportion to weight, melted, and cooled to prepare a fully degradable PLA composite material with ceramic properties. Specifically, the filler is modified with methyl hydrogen-containing polysilazane and bio-based maleic anhydride grafts, enabling interfacial synergy between the matrix resin and the modified filler. This improves the material's hardness, density, and impact strength, precisely mimicking the hard and brittle characteristics of ceramics. Controllable synergy in degradation performance is achieved, ensuring structural stability during the target's use phase while enabling rapid degradation after disposal. Furthermore, multi-component synergistic performance balance is achieved, ensuring the material matches the key performance requirements of ceramic flying saucers, thus achieving the dual goals of "ceramic performance biomimicry" and "environmentally friendly and controllable degradation." If the filler is prepared using a specific method, a compatible interface can be constructed through gradient modification, strengthening its interaction with PLA / PBS; process synergy endows the material with the core properties of biomimetic ceramics; and structural design achieves controllable synergy in degradation performance.

[0038] In summary, this application includes at least one of the following beneficial technical effects:

[0039] 1. By precisely controlling the proportions of PLA, PBS, fillers, and processing aids, and combining them with a specific modification system, synergistic effects among the components are achieved, enhancing the interfacial compatibility between the components, reducing stress concentration, and improving the material's hardness, density, impact strength, and other properties, thus precisely mimicking the hard and brittle characteristics of bioceramics.

[0040] 2. The natural components in bio-based maleic anhydride grafts can accelerate the material degradation process, and the siloxane layer formed by methyl hydrogen-containing polysilazane can delay premature degradation in the unused state, realize the controllability of the degradation process, and solve the problem of "difficulty in balancing stability and degradability" in traditional environmentally friendly materials.

[0041] 3. The inorganic components of the filler, the ratio of PLA / PBS, and the synergistic effect of the modifier enable the material to meet the usage requirements of ceramic flying saucers in terms of key indicators, and all components have bio-based or biodegradable characteristics, achieving the dual goals of "bionic ceramic performance" and "environmentally friendly and controllable degradation". Detailed Implementation

[0042] The present application will be further described in detail below with reference to the embodiments.

[0043] Introduction to some raw materials:

[0044] PLA has a number-average molecular weight of 30,000-50,000.

[0045] The molecular weight of PBS is 50,000-100,000 g / mol;

[0046] The hydrogen content of methyl hydrogen-containing polysilazane is 0.51-1.12%, and the molecular weight is approximately 1500-3160 g / mol;

[0047] The weight-average molecular weight (Mw) of maleic anhydride-grafted poly(butylene adipate-terephthalate) is 80,000-200,000 g / mol, and the maleic anhydride grafting rate is 0.8-1.5%.

[0048] The weight-average molecular weight (Mw) of maleic anhydride-grafted polyvinyl alcohol is 80,000-150,000 g / mol, and the maleic anhydride grafting rate is 3.5-4.8%; the weight-average molecular weight (Mw) of octenyl succinic anhydride-modified starch is 1,000,000-2,000,000 g / mol, and the maleic anhydride grafting rate is 0.10-0.48%.

[0049] Both barium sulfate and talc have a particle size of 500-1000 mesh.

[0050] Example of filler preparation

[0051] Preparation Example 1

[0052] A filler is prepared by dispersing 1 part by weight of methyl hydrogen-containing polysilazane in 10 parts by weight of ethyl acetate to obtain a methyl hydrogen-containing polysilazane solution;

[0053] The inorganic filler and the methyl hydrogen-containing polysilazane solution were placed in a planetary mixer and stirred at 80 r / min for 10 min to ensure thorough mixing. The mixture was then placed in a vacuum drying device at 60 °C and dried until the ethyl acetate was completely removed to obtain mixture A.

[0054] The bio-based maleic anhydride graft in the heating and stirring device is heated to 180°C at 5°C / min until it melts and becomes fluid, while maintaining the stirring speed at 60 r / min. Then, mixture A is added and stirring is continued for 30 min to ensure thorough mixing. After cooling to room temperature, it is then placed in a pulverizer for pulverization and sieved through a 100-mesh sieve to obtain the filler.

[0055] The modifier is used at 10 wt% of the filler; the weight ratio of methyl hydrogen-containing polysilazane and bio-based maleic anhydride graft is 1:2; the bio-based maleic anhydride graft is maleic anhydride-grafted poly(butylene adipate-terephthalate); and the inorganic filler is barium sulfate.

[0056] Preparation Example 2

[0057] The difference between Preparation Example 2 and Preparation Example 1 is that: the amount of modifier is 16 wt% of the filler; the weight ratio of methyl hydrogen-containing polysilazane and bio-based maleic anhydride graft is 1:3; and the inorganic filler is composed of barium sulfate and talc in a weight ratio of 4:1.

[0058] Preparation Example 3

[0059] The difference between Preparation Example 3 and Preparation Example 1 is that the amount of modifier used is 8 wt% of the filler; and the weight ratio of methyl hydrogen-containing polysilazane and bio-based maleic anhydride graft is 1:1.

[0060] Preparation Example 4

[0061] The difference between Preparation Example 4 and Preparation Example 1 is that the bio-based maleic anhydride graft is maleic anhydride grafted with polyvinyl alcohol.

[0062] Preparation Example 5

[0063] The difference between Preparation Example 5 and Preparation Example 1 is that the bio-based maleic anhydride graft is octenyl succinic anhydride modified starch.

[0064] Preparation Example 6

[0065] The difference between Preparation Example 6 and Preparation Example 1 is that the bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate) and maleic anhydride-grafted polyvinyl alcohol in a weight ratio of 1:1.

[0066] Preparation Example 7

[0067] The difference between Preparation Example 7 and Preparation Example 1 is that the bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate) and octenyl succinic anhydride-modified starch in a weight ratio of 1:1.

[0068] Preparation Example 8

[0069] The difference between Preparation Example 8 and Preparation Example 1 is that the bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch in a weight ratio of 1:0.5:1.

[0070] Preparation Example 9

[0071] The difference between Preparation Example 9 and Preparation Example 1 is that the bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch in a weight ratio of 1:1:2.

[0072] Preparation Example 10

[0073] The difference between Preparation Example 10 and Preparation Example 1 is that the bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch in a weight ratio of 1:1:3.

[0074] Preparation of comparative examples

[0075] Preparation of Comparative Example 1

[0076] The difference between Comparative Example 1 and Preparation Example 1 is that methyl hydrogen-containing polysilazane was replaced with a bio-based maleic anhydride graft.

[0077] Preparation of Comparative Example 2

[0078] The difference between Comparative Example 2 and Example 1 is that the bio-based maleic anhydride graft was replaced with an equal amount of methyl hydrogen-containing polysilazane.

[0079] Preparation of Comparative Example 3

[0080] The difference between Comparative Example 3 and Preparation Example 1 is that the modifier used in Comparative Example 3 is KH550; the specific preparation process is as follows:

[0081] KH550 is mixed evenly with the filler to obtain the filler.

[0082] Example

[0083] Example 1

[0084] A fully degradable PLA composite material with ceramic properties is prepared by the following method:

[0085] According to the weight parts, 35 parts PLA, 8 parts PBS, 55 parts filler obtained in Preparation Example 1, and 2 parts processing aid were weighed and placed into a high-speed mixer for uniform mixing. The resulting mixture was then placed into a twin-screw extruder for melt extrusion. The extruder temperatures were 150℃, 160℃, 170℃, 175℃, 180℃, 185℃, and 180℃ respectively. After extrusion, the mixture was cooled by a cooling mechanism and then pelletized in a pelletizer to obtain a fully degradable PLA composite material.

[0086] The processing aids consist of antioxidants and lubricants in a 1:1 weight ratio; the antioxidants are antioxidant 1010 and antioxidant 168 in a 1:1 weight ratio. The lubricant is EBS and silicone oil in a 1:1 weight ratio.

[0087] Example 2-3

[0088] The difference between Examples 2-3 and Example 1 lies in the amount of raw materials used, as shown in Table 1 below:

[0089] Table 1. Raw material usage in Examples 1-3

[0090] raw material Example 1 Example 2 Example 3 PLA 35 25 45 PBS 8 13 5 filler 55 60 48 Processing aids 2 2 2

[0091] Example 4-12

[0092] The difference between Examples 4-12 and Example 1 is that the source of the filler is different, as shown in Table 2.

[0093] Table 2. Sources of fillers in Examples 1 and 4-12

[0094] Example Source of filler Example 1 Preparation Example 1 Example 4 Preparation Example 2 Example 5 Preparation Example 3 Example 6 Preparation Example 4 Example 7 Preparation Example 5 Example 8 Preparation Example 6 Example 9 Preparation Example 7 Example 10 Preparation Example 8 Example 11 Preparation Example 9 Example 12 Preparation Example 10

[0095] Comparative Example

[0096] Comparative Example 1

[0097] The difference between Comparative Example 1 and Example 1 is that the filler is barium sulfate.

[0098] Comparative Example 2

[0099] The difference between Comparative Example 2 and Example 1 is that the filler is the same as that prepared in Comparative Example 1.

[0100] Comparative Example 3

[0101] The difference between Comparative Example 3 and Example 1 is that the filler is the filler prepared in Comparative Example 2.

[0102] Comparative Example 4

[0103] The difference between Comparative Example 4 and Example 1 is that the filler is the filler prepared in Comparative Example 3.

[0104] Performance testing

[0105] Detection methods / test methods

[0106] Test (1)

[0107] The fully degradable PLA composite materials obtained in Examples 1-12 and Comparative Examples 1-3 were transferred to an injection molding machine for melt injection molding. The temperature of the injection molding machine was 150°C at the rear of the barrel, 170°C at the middle of the barrel, 175°C at the front of the barrel, and 185°C at the nozzle. After cooling and solidification, the samples were demolded and used for the following experiments.

[0108] Physical properties

[0109] Shore hardness: Tested using a Shore hardness tester, with reference to ASTM D2240.

[0110] Impact strength: Refer to the notched impact strength of a cantilever beam (ISO 179 standard), test conditions 23℃.

[0111] Density: Measured using a hydrostatic balance.

[0112] When simultaneously achieving a smooth, unblemished surface, Shore hardness >81D, and impact strength of 2-4 kJ / m 2 Density 1.93-2.31 g / cm³ 3 If any one of the above criteria is not met, it is considered qualified; otherwise, if only one criterion is not met, it is considered unqualified.

[0113] Controllable degradation

[0114] 1) Stability

[0115] Time: Stability over 3 months (calculate the rate of quality change before and after; the lower the rate of change, the better the quality and the better the durability).

[0116] Conditions: After 3 months of storage at 85% humidity and 40℃, weigh the product again, divide the weight after storage by the weight before storage, and then multiply by 100% to obtain the corresponding stability rate.

[0117] 2) Degradation efficiency: The sample is buried in soil for degradation. If it is completely degraded within 10 months, it is considered qualified; otherwise, it is unqualified.

[0118] The above experimental data are specific;

[0119] Table 3. Experimental data of Examples 1-12 and Comparative Examples 1-4

[0120]

[0121]

[0122] The following analysis was performed using Examples 1-12 and Comparative Examples 1-4 in conjunction with Table 3:

[0123] The physical properties of Comparative Examples 1-4 all failed to meet standards, and their stability was also lower than that of Example 1. This indicates that the filler used was obtained by modifying inorganic fillers with a modifier. The modifier contained methyl hydrogen-containing polysilazane and bio-based maleic anhydride grafts. The resulting filler, when used in a PLA and PBS compound system, could achieve a smooth, defect-free surface, Shore hardness >81D, and impact strength of 2-4 kJ / m. 2 High density 1.93-2.31 g / cm³ 3 It meets the standards, possesses biomimetic ceramic characteristics, can replace ceramic flying saucers, and maintains stable quality in natural environments. Furthermore, it can rapidly degrade after being buried in soil, achieving controlled degradation and improving its practicality.

[0124] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A fully degradable PLA composite material with ceramic properties, characterized in that, It consists of the following raw materials by weight percentage: PLA: 25-45% PBS: 5-13% Filler: 48-60% The remainder is processing aids; The filler is obtained by modifying inorganic fillers with a modifier; The modifier comprises methyl hydrogen polysilazane and bio-based maleic anhydride grafts; The bio-based maleic anhydride graft is composed of one or more of the following: maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch.

2. The fully degradable PLA composite material with ceramic properties according to claim 1, characterized in that: The processing aid is one or more of antioxidants, lubricants, and fluorescent powders.

3. The fully degradable PLA composite material with ceramic properties according to claim 2, characterized in that: The antioxidant is antioxidant 1010 and / or antioxidant 168.

4. The fully degradable PLA composite material with ceramic properties according to claim 2, characterized in that: The lubricant is EBS and / or silicone oil.

5. The fully degradable PLA composite material with ceramic properties according to claim 1, characterized in that: The inorganic filler is barium sulfate and / or talc.

6. The fully degradable PLA composite material with ceramic properties according to claim 1, characterized in that: The amount of the modifier is 8-20 wt% of the filler.

7. The fully degradable PLA composite material with ceramic properties according to claim 1, characterized in that: The weight ratio of the methyl hydrogen-containing polysilazane to the bio-based maleic anhydride graft is 1:(1-3).

8. The fully degradable PLA composite material with ceramic properties according to claim 1, characterized in that: The bio-based maleic anhydride graft is composed of maleic anhydride-grafted poly(butylene adipate-terephthalate), maleic anhydride-grafted polyvinyl alcohol, and octenyl succinic anhydride-modified starch in a weight ratio of 1:(0.5-1):(1-3).

9. The fully degradable PLA composite material with ceramic properties according to any one of claims 1-8, characterized in that, The filler is prepared by the following method: Methyl hydrogen-containing polysilazane was dispersed in ethyl acetate to obtain a methyl hydrogen-containing polysilazane solution; The inorganic filler was mixed evenly with a methyl hydrogen-containing polysilazane solution, dried, and the ethyl acetate was removed to obtain mixture A. The bio-based maleic anhydride graft is heated and melted into a fluid state, then mixed with mixture A, stirred evenly, cooled, and pulverized to obtain the filler.

10. A method for preparing a fully degradable PLA composite material with ceramic properties as described in any one of claims 1-9, characterized in that, Includes the following steps: Weigh PLA, PBS, filler, and processing aids according to their weight, mix them evenly, melt and mix them evenly, and then cool them to obtain a fully degradable PLA composite material.

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