Hydrolysis-resistant degradable material and preparation method thereof
By introducing water-absorbing materials and modified inorganic fillers into biodegradable materials to form a cross-linked network structure, the hydrolytic stability problem of aliphatic polyester materials is solved, and the hydrolytic resistance and lifespan of materials are improved under high temperature and high humidity environments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- YUANJIA BIOTECHNOLOGY (QUZHOU) CO LTD
- Filing Date
- 2026-05-13
- Publication Date
- 2026-06-16
AI Technical Summary
Existing aliphatic polyester biodegradable materials have defects in hydrolytic stability, especially in high temperature and high humidity environments where the hydrolysis reaction is intensified, leading to a decline in material performance and limiting their application range.
By introducing water-absorbing materials such as aluminosilicates and calcium oxide into the biodegradable matrix polymer, water molecules are competitively adsorbed using their microporous structure and chemical adsorption capacity. Furthermore, the surface of the inorganic water-absorbing filler is modified by grafting carboxyl-terminated polybutadiene to improve dispersibility and form a cross-linked network structure. Combined with an epoxy chain extender, autocatalytic hydrolysis is blocked, thereby enhancing the hydrolysis resistance of the material.
It effectively reduces the rate of hydrolysis reaction in biodegradable materials, improves thermal stability and mechanical properties, and extends the service life of materials, especially maintaining good hydrolysis resistance in high temperature and high humidity environments.
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Abstract
Description
Technical Field
[0001] This invention relates to the field of biodegradable materials technology, and in particular to a hydrolysis-resistant biodegradable material and its preparation method. Background Technology
[0002] With increasing emphasis on environmental protection and sustainable development, the "white pollution" problem caused by traditional petroleum-based plastics has become increasingly prominent. Developing and using biodegradable materials has become one of the important ways to solve the problem of petroleum-based plastic waste disposal. Among biodegradable materials, polylactic acid (PLA) and polyhydroxyalkanoates (PHA) are biodegradable polyester materials. They have advantages such as renewable raw materials, low carbon emissions, and good biodegradability, making them highly representative of biodegradable materials. They have been widely used in disposable tableware, packaging films, agricultural mulch films, 3D printing, and biomedical engineering.
[0003] However, these types of polyester biodegradable materials generally suffer from poor hydrolytic stability during storage, processing, and use in practical applications. These biodegradable materials belong to aliphatic polyesters, and their molecular backbone contains a large number of ester bonds. Ester bonds have a certain degree of hydrophilicity. In the presence of water molecules, especially when the content of free water molecules in the environment is high, water molecules easily attack ester bonds, causing ester bonds to break, triggering hydrolysis, degrading the main chain, and consequently causing a sharp decrease in the molecular weight of the polymer.
[0004] Especially in the hot and humid environment of summer, the hydrolysis reaction will be further catalyzed, the hydrolysis rate will increase, the mechanical properties will drop sharply, resulting in a significant reduction in the service life of the products and limiting the application scenarios of this type of biodegradable material.
[0005] Therefore, in order to expand the application range of this type of high-performance biodegradable material, enable it to better adapt to more stringent storage and use environments, and improve the service life of products, it is of great significance to obtain a biodegradable material with stable performance and excellent hydrolysis resistance. Summary of the Invention
[0006] The purpose of this invention is to provide a hydrolysis-resistant biodegradable material and its preparation method, so as to solve the technical problem of poor hydrolysis resistance of aliphatic polyester biodegradable materials in the prior art.
[0007] The technical problem to be solved by this invention can be achieved through the following technical solution: In a first aspect, the present invention provides a hydrolysis-resistant biodegradable material comprising the following raw materials in parts by weight: 10–90 parts of biodegradable matrix polymer; 1-50 parts of absorbent material; Other adjuvants: 0-50 parts; Water-absorbing materials include any one of inorganic water-absorbing fillers and their masterbatches.
[0008] Preferably, the biodegradable matrix polymer includes either polylactic acid or polyhydroxyalkanoate; Inorganic absorbent fillers include aluminosilicates and calcium oxide.
[0009] Preferably, the masterbatch of inorganic water-absorbing filler is obtained by twin-screw melt extrusion and granulation of a biodegradable matrix polymer, inorganic water-absorbing filler and antioxidant in a mass ratio of 100:(12-18):(0.5-1).
[0010] Preferably, other additives include one or more combinations of reinforcing agents, antioxidants, and anti-hydrolysis agents.
[0011] Preferably, the reinforcing agent includes one or more combinations of PBAT, TPU, MBS, starch, calcium carbonate and talc.
[0012] More preferably, the antioxidant includes one or more combinations of antioxidant 1010, antioxidant 1076, antioxidant 1330, antioxidant 168, antioxidant 626 and antioxidant DLTP.
[0013] More preferably, the hydrolysis resistant agent includes one or more combinations of Stabaxol™ P100, hydrolysis resistant agent UN-150, hydrolysis resistant agent AH-3000L, hydrolysis resistant agent AW700 and hydrolysis resistant agent BTWR-100.
[0014] By adopting the above technical solution, the present invention introduces a water-absorbing material into a biodegradable matrix polymer. The water-absorbing material can reduce the effective water concentration around the biodegradable matrix polymer molecules by competitively and preferentially adsorbing and chemically fixing water molecules, thereby alleviating the hydrolysis reaction of ester bonds.
[0015] Specifically, this invention selects aluminosilicates, calcium oxide, or their masterbatches as water-absorbing materials. Aluminosilicates have a regular microporous structure, and their three-dimensional channels have a strong capillary coagulation and physical adsorption capacity for water molecules. Water molecules will preferentially enter the channels of aluminosilicates and be captured. Calcium oxide can convert water molecules into bound water and fix them. Through competitive adsorption and capture, the number of water molecules that freely diffuse to the vicinity of the degradable matrix polymer is reduced, the concentration of water molecules reaching the vicinity of the polymer ester bonds is reduced, and thus the hydrolysis reaction rate is slowed down.
[0016] Because the reaction rate between water molecules and the biodegradable matrix polymer is much lower than the rate at which water molecules are captured by the inorganic filler, water molecules attempting to penetrate the matrix polymer are intercepted and solidified by the absorbent material. This keeps the water molecule concentration in the biodegradable material at an extremely low level, thereby inhibiting the hydrolysis reaction. Furthermore, the inorganic absorbent filler can be pre-treated to prepare masterbatches, which improves its dispersibility and absorption efficiency.
[0017] Meanwhile, both polylactic acid (PLA) and polyhydroxyalkanoates (PHA) are semi-crystalline polymers, resulting in poor thermal stability and temperature resistance, and more intense hydrolysis at high temperatures. The addition of absorbent materials can act as heterogeneous nucleating agents, increasing the crystallization rate and crystallinity of the biodegradable matrix polymer, thereby raising the heat distortion temperature and enhancing the thermal stability of the biodegradable material. This allows the product to effectively resist hydrolysis and maintain dimensional stability even in high-temperature and high-humidity environments. Furthermore, the rigidity of the absorbent material itself can compensate for the performance limitations of the biodegradable matrix polymer, improving the mechanical properties of the biodegradable material and contributing to the development of a hydrolysis-resistant biodegradable material with excellent overall performance.
[0018] Preferably, the inorganic absorbent filler is further modified; the surface of the modified inorganic absorbent filler is grafted with terminal carboxyl polybutadiene.
[0019] Preferably, the inorganic water-absorbing filler is modified according to the following method: Pretreatment: Add epoxy silane coupling agent to anhydrous ethanol, stir to dissolve, then add inorganic water-absorbing filler, stir and react at room temperature for 30-60 minutes, then filter, dry and grind to obtain pretreated inorganic water-absorbing filler; Modification treatment: Dissolve carboxyl-terminated polybutadiene in xylene, then add pretreated inorganic water-absorbing filler, stir and disperse, and reflux at 125-135℃ for 4-5 hours. Finally, filter, wash and dry to obtain the product.
[0020] Preferably, the mass-to-volume ratio of inorganic water-absorbing filler, epoxy silane coupling agent and carboxyl-terminated polybutadiene is 1 g: (0.02-0.1) mL: (0.7-0.85) mL.
[0021] More preferably, the epoxy silane coupling agent includes one or more combinations of γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane.
[0022] By adopting the above technical solution, the epoxy silane coupling agent is hydrolyzed in anhydrous ethanol to generate active silanol groups, which then undergo a condensation reaction with the free hydroxyl groups on the surface of the inorganic water-absorbing filler. The epoxy silane coupling agent is first attached to the surface of the inorganic water-absorbing filler. Then, the pretreated inorganic water-absorbing filler is added to the carboxyl-terminated polybutadiene solution. The carboxyl groups contained in the filler can react with the epoxy groups on the surface of the pretreated inorganic water-absorbing filler. The epoxy silane coupling agent acts as a reaction bridge to graft the carboxyl-terminated polybutadiene onto the surface of the inorganic water-absorbing filler.
[0023] Because inorganic water-absorbing fillers have a large specific surface area, they are prone to agglomeration during the blending modification process. This not only becomes a stress concentration point in the biodegradable material, affecting the material's performance, but also affects the water absorption efficiency. The filler particles inside the agglomerate are buried, resulting in a reduction in the effective water absorption area. Furthermore, after prolonged use, the agglomerates absorb excessive water, which can cause hydrolysis of the surrounding polymer molecular chains, thus worsening the improvement effect on hydrolysis resistance.
[0024] This invention uses carboxyl-terminated polybutadiene to modify inorganic absorbent fillers. On the one hand, the carboxyl-terminated groups form hydrogen bonds with the biodegradable matrix polymer, and the synergistic spatial effect of the polymer chain segments can help improve the dispersibility and compatibility of the inorganic absorbent filler in the biodegradable matrix polymer, and reduce agglomeration.
[0025] On the other hand, after modification, even if polymer segments are grafted onto the surface of the absorbent material, a continuous dense film will not be formed, affecting the competitive water absorption capacity of the inorganic absorbent filler. Moreover, through the barrier layer of carboxyl-terminated polybutadiene, the one-time rapid water absorption effect of the original inorganic absorbent filler can be transformed into a controllable slow release, thereby greatly extending the duration of the hydrolysis resistance of the biodegradable material and improving its service life. Furthermore, when the biodegradable matrix polymer begins to hydrolyze, the generated carboxyl groups will promote the water absorption efficiency of the modified inorganic absorbent filler, accelerate the transfer of water molecules to the inorganic absorbent filler, and allow the inorganic absorbent filler to respond more efficiently, thereby slowing down the hydrolysis process.
[0026] Furthermore, improving the dispersibility of inorganic water-absorbing fillers allows the fillers to be fully exposed to the water molecule environment, greatly increasing the effective water absorption area and improving the overall water absorption capacity.
[0027] Preferably, the raw materials for biodegradable materials also include 0.5 to 1 part of epoxy chain extender.
[0028] More preferably, the epoxy chain extender includes one or more of the following: chain extender ADR-4468, chain extender ADR-4370, chain extender ADR4370S, chain extender 3700, and chain extender KL-E4370.
[0029] By adopting the above technical solution, the biodegradable matrix polymer will generate terminal carboxyl groups after hydrolysis. The formed terminal carboxyl groups will further catalyze the hydrolysis of the remaining ester bonds, thereby forming a self-accelerated hydrolysis process. The addition of epoxy chain extender can react with the formed terminal carboxyl groups to open the ring and block the process of self-catalytic hydrolysis.
[0030] Furthermore, the epoxy chain extender can react with the carboxyl groups on the terminally carboxyl polybutadiene grafted onto the modified inorganic absorbent filler, thereby establishing a chemical cross-linking bridge between the inorganic absorbent filler and the biodegradable matrix polymer. This not only further improves dispersibility but also, by connecting multiple polymer chains with the inorganic absorbent filler, forms a flexible three-dimensional interpenetrating or micro-crosslinked network within the biodegradable material. This allows the material to maintain good mechanical properties even after hydrolysis, reducing the rate of performance degradation. Simultaneously, the formed network structure effectively hinders the diffusion and penetration of water molecules within the biodegradable material, indirectly improving its hydrolysis resistance.
[0031] Secondly, the present invention provides a method for preparing a hydrolysis-resistant biodegradable material, comprising the following process steps: S1. After weighing each raw material, stir it evenly in a mixing tank to obtain a premix; S2. The premixed material is melt-extruded at 150-220℃, cooled and granulated to obtain a hydrolysis-resistant biodegradable material.
[0032] The beneficial effects of this invention are: 1. The hydrolysis-resistant biodegradable material provided by the present invention introduces a water-absorbing material. The water-absorbing material reduces the number of water molecules that freely diffuse to the surroundings of the biodegradable matrix polymer through competitive adsorption and capture, and reduces the concentration of water molecules near the polymer ester bonds, thereby keeping the concentration of water molecules inside the material at an extremely low level, thereby inhibiting the hydrolysis reaction. In addition, the addition of the water-absorbing material can also improve thermal stability, and can maintain good hydrolysis resistance even in high temperature and high humidity environments.
[0033] 2. In the hydrolysis-resistant biodegradable material provided by the present invention, the inorganic water-absorbing filler can be modified. The surface of the modified inorganic water-absorbing filler is grafted with carboxyl-terminated polybutadiene, which can improve the dispersibility of the inorganic water-absorbing filler in the matrix polymer through hydrogen bonding and steric hindrance effect, thereby further improving the hydrolysis resistance of the material.
[0034] 3. The hydrolysis-resistant biodegradable material provided by this invention can also be supplemented with epoxy chain extenders, which can not only effectively block the autocatalytic process after hydrolysis of the biodegradable matrix polymer, but also combine with the modified inorganic water-absorbing filler, so that the inorganic water-absorbing filler and the matrix polymer can also be effectively connected. The network structure formed can reduce the rate of performance degradation and indirectly improve the hydrolysis resistance of the material. Detailed Implementation
[0035] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.
[0036] Preparation Example Preparation Example 1: An inorganic water-absorbing filler was modified according to the following method: Pretreatment: Add 0.4 mL of γ-glycidoxypropyltrimethoxysilane to 150 mL of anhydrous ethanol, stir to dissolve, then add 10 g of aluminosilicate (particle size 200-300 mesh), stir and react at room temperature for 40 min, then filter, dry and grind to obtain the pretreated inorganic water-absorbing filler. Modification treatment: Dissolve 8 mL of carboxyl-terminated polybutadiene in xylene to prepare a 2% (w / w) carboxyl-terminated polybutadiene solution. Then add the pretreated inorganic water-absorbing filler obtained above, stir and disperse, and reflux at 130℃ for 4 h. Finally, filter, wash and dry to obtain the final product.
[0037] Preparation Example 2, an inorganic water-absorbing filler, differs from Preparation Example 1 only in that an equal amount of calcium oxide (average particle size of 3 μm) is used to replace aluminosilicate.
[0038] Preparation Example 3, an inorganic water-absorbing filler, differs from Preparation Example 1 only in that the amount of carboxyl-terminated polybutadiene added is 5 mL.
[0039] Preparation Example 4, an inorganic water-absorbing filler, differs from Preparation Example 1 only in that the amount of carboxyl-terminated polybutadiene added is 10 mL.
[0040] Example Example 1: A hydrolysis-resistant biodegradable material was prepared according to the following method: S1. Weigh out 85 parts of polylactic acid (average molecular weight 2.0 × 10⁻⁶). 4 ), 5 parts aluminosilicate (particle size of 200-300 mesh) and 2 parts antioxidant, the antioxidant including antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, are stirred evenly in a mixing tank to obtain a premix; S2. The premixed material is melt-extruded at 150-220℃, cooled and granulated to obtain a hydrolysis-resistant biodegradable material.
[0041] Example 2, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that it uses an equal amount of polyhydroxyalkanoate (average molecular weight 2.3 × 10⁻⁶). 4 Replace polylactic acid.
[0042] Example 3, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that an equal amount of calcium oxide (average particle size of 3 μm) is used to replace aluminosilicate.
[0043] Example 4: A hydrolysis-resistant biodegradable material was prepared according to the following method: S1. Weigh out 50 parts of polylactic acid (average molecular weight 2.0 × 10⁻⁶). 4 ), 40 parts aluminosilicate polylactic acid masterbatch and 2 parts antioxidant, the aluminosilicate polylactic acid masterbatch is composed of polylactic acid (average molecular weight 2.0×10) in a mass ratio of 100:14:1. 4 Aluminosilicate (particle size 200-300 mesh) and antioxidant are obtained by melt extrusion and granulation of twin screw extruder at a temperature of 165-230℃. The antioxidant includes antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1. The mixture is stirred evenly in a mixing tank to obtain a premix. S2. The premixed material is melt-extruded at 150-220℃, cooled and granulated to obtain a hydrolysis-resistant biodegradable material.
[0044] Example 5, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that the aluminosilicate is replaced with the inorganic water-absorbing filler prepared in Example 1.
[0045] Example 6, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that the aluminosilicate is replaced with the inorganic water-absorbing filler prepared in Preparation Example 2.
[0046] Example 7, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that the aluminosilicate is replaced with the inorganic water-absorbing filler prepared in Preparation Example 3.
[0047] Example 8, a hydrolysis-resistant biodegradable material, differs from Example 1 only in that the aluminosilicate is replaced with the inorganic water-absorbing filler prepared in Preparation Example 4.
[0048] Example 9, a hydrolysis-resistant biodegradable material, differs from Example 5 only in that 0.6 parts of epoxy chain extender ADR-4468 are added to the premix.
[0049] Comparative Example Comparative Example 1 is a hydrolysis-resistant biodegradable material, which differs from Example 1 only in that an equal amount of anti-hydrolysis agent UN-150 is used to replace the aluminosilicate.
[0050] Comparative Example 2, a hydrolysis-resistant biodegradable material, was prepared according to the following method: S1. Weigh out 85 parts of polylactic acid (average molecular weight 2.0 × 10⁻⁶). 4 ) and 2 parts antioxidants, the antioxidants being antioxidant 1010 and antioxidant 168 in a mass ratio of 1:1, are stirred evenly in a mixing tank to obtain a premix; S2. The premixed material is melt-extruded at 150-220℃, cooled and granulated to obtain a hydrolysis-resistant biodegradable material.
[0051] Performance testing methods 1. Mechanical property testing: (1) Tensile property test: The tensile strength of the biodegradable materials obtained in the examples and comparative examples was tested according to the relevant records in GB / T 1040.1-2025 "Determination of tensile properties of plastics - Part 1: General". (2) Impact performance test: The impact strength of the cantilever beams of the biodegradable materials obtained in the examples and comparative examples was tested according to the relevant records in GB / T 1843-2008 "Determination of impact strength of plastic cantilever beams".
[0052] 2. Hydrolysis resistance test: (1) The test specimens for mechanical property testing were placed in a constant temperature and humidity chamber at 50℃ and 40% relative humidity for 30 days. After 30 days, they were taken out, dried, and tested for tensile strength and cantilever beam impact strength. The retention rates of tensile strength and cantilever beam impact strength before and after treatment were compared. (2) The water content of the biodegradable materials obtained in the test examples and comparative examples was tested, and the materials were left to stand for 24 hours under environmental conditions of 32°C and 25% relative humidity. The water content was then tested again.
[0053] The results of the above experiments are shown in Table 1: Table 1 Performance test results
[0054] According to Table 1, and in conjunction with Examples 1 and 5, it can be seen that the initial mechanical properties of Example 5 are better and the hydrolysis resistance is more superior than that of Example 1. The reason may be that the inorganic water-absorbing filler was grafted and modified in Example 5. The grafting of carboxyl-terminated polybutadiene can improve the dispersibility of the inorganic water-absorbing filler in the matrix polymer, which is not only beneficial to the improvement of mechanical strength, but also to the improvement of hydrolysis resistance.
[0055] Combining Examples 5 and 9, it can be seen that the performance of Example 9 is improved compared to Example 5. The reason may be that, in addition to adding the modified inorganic water-absorbing filler, Example 9 also adds an epoxy chain extender, which can not only improve the binding density inside the biodegradable material, but also further inhibit the occurrence and development of hydrolysis. After hydrolysis, it can form a stable hydrolysis-resistant network, thereby improving the overall hydrolysis resistance performance.
[0056] Combining Examples 1, 1, and 2, it can be seen that the performance of Comparative Example 1 is lower than that of Example 1, and the decrease is more significant in Comparative Example 2. This may be because Comparative Example 2 did not add any additives to improve hydrolysis, resulting in a lack of protection for the biodegradable matrix polymer under high temperature and humidity conditions, leading to rapid hydrolysis and a significant decrease in overall molecular weight, thus reducing performance. In contrast, Comparative Example 1 used conventional anti-hydrolysis agents, which cannot effectively prevent hydrolysis reactions and have a slow response to hydrolysis, thus demonstrating superior hydrolysis resistance in this application.
[0057] The above-disclosed embodiments are merely a few specific examples of the present invention. However, the embodiments of the present invention are not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.
Claims
1. A hydrolysis-resistant biodegradable material, characterized in that, The raw materials include the following parts by weight: 10–90 parts of biodegradable matrix polymer; 1-50 parts of absorbent material; Other adjuvants: 0-50 parts; The absorbent material includes any one of inorganic absorbent fillers and their masterbatches.
2. The hydrolysis-resistant biodegradable material according to claim 1, characterized in that, The biodegradable matrix polymer includes either polylactic acid or polyhydroxyalkanoate; The inorganic water-absorbing filler includes aluminosilicate and calcium oxide.
3. The hydrolysis-resistant biodegradable material according to claim 1, characterized in that, The masterbatch of the inorganic water-absorbing filler is obtained by twin-screw melt extrusion and granulation of a biodegradable matrix polymer, inorganic water-absorbing filler and antioxidant in a mass ratio of 100:(12-18):(0.5-1).
4. The hydrolysis-resistant biodegradable material according to claim 1, characterized in that, The inorganic absorbent filler has also undergone modification treatment; the surface of the modified inorganic absorbent filler is grafted with carboxyl-terminated polybutadiene.
5. The hydrolysis-resistant biodegradable material according to claim 1, characterized in that, The inorganic water-absorbing filler is modified according to the following method: Pretreatment: Add epoxy silane coupling agent to anhydrous ethanol, stir to dissolve, then add inorganic water-absorbing filler, stir and react at room temperature for 30-60 minutes, then filter, dry and grind to obtain pretreated inorganic water-absorbing filler; Modification treatment: Dissolve carboxyl-terminated polybutadiene in xylene, then add pretreated inorganic water-absorbing filler, stir and disperse, and reflux at 125-135℃ for 4-5 hours. Finally, filter, wash and dry to obtain the product.
6. The hydrolysis-resistant biodegradable material according to claim 5, characterized in that, The mass-to-volume ratio of the inorganic water-absorbing filler, epoxy silane coupling agent, and carboxyl-terminated polybutadiene is 1 g: (0.02–0.1) mL: (0.7–0.85) mL.
7. The hydrolysis-resistant biodegradable material according to claim 4, characterized in that, The raw materials for the biodegradable material also include 0.5 to 1 part of epoxy chain extender.
8. The hydrolysis-resistant biodegradable material according to claim 1, characterized in that, The other additives include one or more combinations of reinforcing agents, antioxidants, and anti-hydrolysis agents.
9. The hydrolysis-resistant biodegradable material according to claim 8, characterized in that, The reinforcing agent includes one or more of PBAT, TPU, MBS, starch, calcium carbonate, and talc.
10. A method for preparing a hydrolysis-resistant biodegradable material, used to prepare the hydrolysis-resistant biodegradable material according to any one of claims 1 to 9, characterized in that, The process includes the following steps: S1. After weighing each raw material, stir it evenly in a mixing tank to obtain a premix; S2. The premixed material is melt-extruded at 150-220℃, cooled and granulated to obtain a hydrolysis-resistant biodegradable material.