Modified polylactic acid oligomer, preparation method therefor, and use thereof

Abstract

The present invention relates to a modified polylactic acid oligomer, a preparation method therefor, and a use thereof. The modified polylactic acid oligomer has a structure as shown in the following formula (I). The modified polylactic acid oligomer obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid in the present invention exhibits more excellent, stable, and long-lasting antibacterial activity, significantly improved antibacterial efficiency, an increased sterilization rate, and shortened sterilization time; when the modified polylactic acid oligomer is applied to various antibacterial coatings and textile finishing processes, the surface no longer exhibits a wet and sticky feel, thereby further facilitating the commercialization and widespread application of the material; in addition, the modified polylactic acid oligomer exhibits higher affinity for a target substrate, thereby improving the durability, stability, and washing resistance of a surface coating.

Description

A modified polylactic acid oligomer, its preparation method and uses

[0001] This invention claims priority to two Chinese patent applications filed on January 6, 2025, with application number 2025100177616, entitled "A modified polylactic acid oligomer and its preparation method and use", and filed on June 3, 2025, with application number 2025107314084, also entitled "A modified polylactic acid oligomer and its preparation method and use", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention belongs to the field of antibacterial materials technology, specifically relating to a modified polylactic acid oligomer, its preparation method and uses, and its applications in the fields of medicine, medical materials, textiles, hygiene products, environment, food, food packaging, dyeing and finishing auxiliaries, paints, surface coatings, plastics and agricultural products. Background Technology

[0003] As people's demands for medical and health standards increase, the social demand for antibacterial materials is growing daily. Current antibacterial materials mainly include inorganic, organic, and natural antibacterial materials. Inorganic materials have high antibacterial efficiency, such as nano-silver antibacterial agents, but their biosafety is low, and they accumulate in the body and cannot be degraded. Organic antibacterial materials, such as biguanides, have high toxicity and potential carcinogenicity. Natural antibacterial materials have relatively good safety, but the sources of raw materials are complex, their antibacterial effects are unstable, and their antibacterial efficiency is relatively low. Biodegradable materials based on polyhydroxyalkyl esters, such as polylactic acid oligomers, have high biosafety and can balance safety, antibacterial efficiency, and environmental friendliness, making them a better type of antibacterial material that aligns with the trend of sustainable development.

[0004] However, polylactic acid oligomers still have some problems as an antibacterial material. For example, to achieve a high antibacterial rate and faster sterilization effect, a relatively high dosage or concentration is required; if used in antibacterial coatings or finishing agents, they may feel sticky to the touch; due to their small molecular weight, their van der Waals forces with the substrate are weak, resulting in poor wash resistance and stability; and due to their inherent biochemical properties, their antibacterial effect against some bacterial species is relatively weak. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a modified polylactic acid oligomer to improve the antibacterial efficiency, practicality and stability of polylactic acid oligomers, thereby enabling them to be used more widely.

[0006] The technical solutions for achieving the above objectives include the following.

[0007] In a first aspect, the present invention provides a modified polylactic acid oligomer having the structure shown in formula (I),

[0008] Where n and m are independently selected from integers from 1 to 100.

[0009] The modified polylactic acid oligomer of the present invention is obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid, and the number average molecular weight of the modified polylactic acid oligomer is 100 to 10,000.

[0010] Secondly, the present invention provides a method for preparing the modified polylactic acid oligomer, comprising the following steps:

[0011] Under inert gas protection, 5-hydroxy-2-hexenoic acid and lactic acid undergo a copolymerization reaction at a temperature of 100℃~300℃ and a pressure of 5Pa~5MPa to obtain the modified polylactic acid oligomer.

[0012] Furthermore, the method also includes the preparation of 5-hydroxy-2-hexenoic acid, wherein the preparation method of 5-hydroxy-2-hexenoic acid includes the following steps:

[0013] Under acidic conditions, 2,4-hexadienoic acid reacts with water to yield 5-hydroxy-2-hexadienoic acid.

[0014] Thirdly, the present invention also provides the application of the modified polylactic acid oligomer in the preparation of antibacterial agents.

[0015] Fourthly, the present invention also provides the application of the modified polylactic acid oligomer in the preparation of preservatives.

[0016] Fifthly, the present invention also provides the application of the modified polylactic acid oligomer in the preparation of acaricides.

[0017] In a sixth aspect, the present invention also provides an antibacterial agent whose active ingredient contains the modified polylactic acid oligomer described in the present invention.

[0018] In a seventh aspect, the present invention also provides a preservative, the active ingredient of which contains the modified polylactic acid oligomer described in the present invention.

[0019] In an eighth aspect, the present invention also provides an acaricide whose active ingredient contains the modified polylactic acid oligomer described in the present invention.

[0020] In a ninth aspect, the present invention also provides the use of the modified polylactic acid oligomer or the antimicrobial agent in the preparation of antimicrobial products.

[0021] In a tenth aspect, the present invention also provides the application of the modified polylactic acid oligomer or the preservative in the preparation of preservative products.

[0022] In an eleventh aspect, the present invention also provides the application of the modified polylactic acid oligomer or the acaricide in the preparation of acaricide products.

[0023] The bacteria can be bacteria (such as Staphylococcus aureus, Escherichia coli, etc.) or fungi (such as Candida albicans, etc.).

[0024] The antibacterial products include antibacterial pharmaceutical preparations (such as microneedles), textiles, paper towels, laundry detergent, food additives, food packaging materials, dyes, dyeing and finishing agents, paints, coatings, surface coating materials, agricultural products, or livestock products, etc.; the preservative products include preservative pharmaceutical preparations, textiles, paper towels, laundry detergent, food additives, or food packaging materials, etc.; the mite-removing products are mite-removing textiles or paper towels, etc.

[0025] In a twelfth aspect, the present invention also provides an antibacterial method, comprising: treating a product requiring antibacterial treatment with the modified polylactic acid oligomer or the antibacterial agent described in the present invention.

[0026] In a thirteenth aspect, the present invention also provides a method for corrosion prevention, comprising: treating the product requiring corrosion prevention with the modified polylactic acid oligomer or the preservative described in the present invention.

[0027] In a fourteenth aspect, the present invention also provides a method for removing mites, comprising: treating the product requiring mite removal with the modified polylactic acid oligomer or the mite-removing agent described in the present invention.

[0028] This invention provides a modified polylactic acid oligomer obtained by copolymerizing 5-hydroxy-2-hexenoic acid and lactic acid. This modified polylactic acid oligomer has the following advantages compared to regular polylactic acid oligomers:

[0029] (1) It has superior and stable antibacterial activity, and has significant inhibitory effects on a variety of bacteria, fungi, viruses, mites, bed bugs, bed bugs, etc. After modification, the materials produce a synergistic antibacterial effect, which greatly improves the antibacterial efficiency, increases the sterilization rate, and shortens the sterilization time. It can achieve better antibacterial effects with lower dosage or concentration and in a shorter time.

[0030] (2) When the modified polylactic acid oligomer is applied to various antibacterial coatings and textile finishing, the surface no longer feels wet and sticky, which is more conducive to the commercialization and widespread application of the material.

[0031] (3) The modified polylactic acid oligomer has a higher affinity for the target substrate, which can improve the durability, stability and washability of the surface coating. The antibacterial textiles obtained after treatment with the modified polylactic acid oligomer can still maintain good antibacterial effect after many washes.

[0032] In addition to its excellent antibacterial activity, the modified polylactic acid oligomer of this invention also possesses excellent biodegradability and biocompatibility. Furthermore, its preparation process is simple, low-cost, safe, and environmentally friendly, making it suitable for industrial production and large-scale use. It can be formulated into various forms or types of antibacterial materials, used in combination with other antibacterial materials, or used to modify other materials to obtain antibacterial agents and materials with superior performance, greatly enriching the types and applications of antibacterial materials. Attached Figure Description

[0033] Figure 1 shows the infrared spectrum of 5-hydroxy-2-hexenoic acid.

[0034] Figure 2 shows the mass spectrum of 5-hydroxy-2-hexenoic acid.

[0035] Figure 3 shows the mass spectrum of the poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1.

[0036] Figure 4 shows the mass spectrum of the poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 5.

[0037] Figure 5 shows the infrared spectrum of the poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 5.

[0038] Figure 6 is an HPLC-MS chromatogram of the polylactic acid oligomer prepared in Comparative Example 1.

[0039] Figure 7 shows the mass spectrum of the poly(5-hydroxy-2-hexenoic acid) oligomer prepared in Comparative Example 2.

[0040] Figure 8 shows the infrared spectrum of the poly(5-hydroxy-2-hexenoic acid) oligomer prepared in Comparative Example 2.

[0041] Figure 9 shows tissue-engineered microneedles based on poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer (A) and polylactic acid oligomer (B).

[0042] Figure 10 shows the mass spectrum of the solid polylactic acid oligomer prepared in Example 7.

[0043] Figure 11 is a comparison of the microneedles prepared in Example 7 before and after their effect on the bacterial wounds of SD rats.

[0044] Figure 12 shows the wound healing effect of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer on bacterial wounds in SD rats. Detailed Implementation

[0045] To facilitate understanding of the present invention, a more complete description will be provided below. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the present invention.

[0046] Unless otherwise specified, experimental methods in the following examples are generally performed under standard conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the examples are commercially available products.

[0047] Unless otherwise defined, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this invention includes any and all combinations of one or more of the associated listed items.

[0048] Furthermore, as used herein, the term "or" is an inclusive "or" sign and is equivalent to the term "and / or" unless the context clearly specifies otherwise. The term "based on" is not exclusive and allows for basing on other factors not described unless the context clearly specifies otherwise. Additionally, throughout the specification, the meanings of "an," "a," and "the" include plural indicators. The meaning of "in" includes both "in" and "on."

[0049] Currently, polylactic acid oligomers, as an antibacterial material, still have some problems. For example, to achieve a high antibacterial rate and faster bactericidal effect, a relatively high dosage or concentration is required; if used in antibacterial coatings or finishing agents, they may have a sticky feel; due to their small molecular weight, the van der Waals forces with the substrate are weak, resulting in insufficient wash resistance and stability; and due to their inherent biochemical properties, their antibacterial effect against some bacterial species is weak. To overcome these problems and enable polylactic acid oligomers to be used more widely, this invention has developed a modified polylactic acid oligomer that effectively improves the antibacterial efficiency, practicality, and stability of polylactic acid oligomers.

[0050] In one embodiment of the present invention, a modified polylactic acid oligomer having the structure shown in formula (I) is provided.

[0051] Where n and m are independently selected from integers from 1 to 100.

[0052] In some embodiments, n is selected from an integer from 1 to 50; m is selected from an integer from 1 to 50.

[0053] In some embodiments, n is selected from an integer from 1 to 20; m is selected from an integer from 1 to 20.

[0054] In some embodiments, n is selected from an integer from 1 to 12; m is selected from an integer from 1 to 12.

[0055] In some embodiments, n is selected from an integer from 2 to 8; m is selected from an integer from 2 to 8.

[0056] In some embodiments, n is selected from an integer from 1 to 6; m is selected from an integer from 1 to 6.

[0057] In some embodiments, n is selected from an integer of 4 to 5; m is selected from an integer of 3 to 4.

[0058] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 2 to 100.

[0059] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 2 to 50.

[0060] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 2 to 12.

[0061] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 3 to 11.

[0062] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 4 to 9.

[0063] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 5 to 8.

[0064] In some embodiments, the modified polylactic acid oligomer has an average degree of polymerization of 7 to 8.

[0065] The modified polylactic acid oligomer of the present invention can be obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid, wherein the number average molecular weight of the modified polylactic acid oligomer is 100 to 10,000.

[0066] In some embodiments, the mass ratio of 5-hydroxy-2-hexenoic acid to lactic acid is 1:0.5 to 3, preferably 1:0.8 to 2, more preferably 1:0.9 to 1.5, and even more preferably 1:0.9 to 1.2.

[0067] In some embodiments, the number average molecular weight of the modified polylactic acid oligomer is 200-3000, preferably 200-1100, more preferably 200-800, more preferably 300-800, more preferably 400-800, and even more preferably 600-700.

[0068] The modified polylactic acid oligomer of the present invention can be obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid through conventional copolymerization reactions in the art.

[0069] In one embodiment of the present invention, the method for preparing the modified polylactic acid oligomer provided by the present invention includes the following steps:

[0070] Under inert gas protection, 5-hydroxy-2-hexenoic acid and lactic acid undergo a copolymerization reaction at a temperature of 100℃~300℃ and a pressure of 5Pa~5MPa to obtain the modified polylactic acid oligomer.

[0071] In one embodiment of the present invention, the preparation method of the modified polylactic acid oligomer provided by the present invention includes the following steps: mixing the 5-hydroxy-2-hexenoic acid and lactic acid, adding water, heating under reflux for 1-3 hours, and then carrying out a copolymerization reaction under inert gas protection at a temperature of 100℃~300℃ and a pressure of 5Pa~5MPa to obtain the modified polylactic acid oligomer.

[0072] In some embodiments, the amount of water added is 4 to 8 times the total weight of 5-hydroxy-2-hexenoic acid and lactic acid, for example, 4, 5, 6, 7, or 8 times.

[0073] In some embodiments, the temperature is 150°C to 250°C, preferably 180°C to 220°C.

[0074] In some embodiments, the pressure is 1000 Pa to 3000 Pa, preferably 1500 Pa to 2500 Pa.

[0075] In some embodiments, the copolymerization reaction time is 0.01 hours to 72 hours, preferably 0.5 hours to 20 hours, preferably 0.5 hours to 16 hours, preferably 0.8 hours to 8 hours, more preferably 1 hour to 7 hours, more preferably 2 hours to 6 hours, and even more preferably 3 hours to 5 hours.

[0076] In some embodiments, the method for preparing the modified polylactic acid oligomer further includes the preparation of 5-hydroxy-2-hexenoic acid, wherein the method for preparing 5-hydroxy-2-hexenoic acid includes the following steps:

[0077] Under acidic conditions, 2,4-hexadienoic acid reacts with water to yield 5-hydroxy-2-hexadienoic acid.

[0078] In some embodiments, the pH of the acidic conditions is 1.0 to 4.0, preferably 2.0 to 3.5.

[0079] In some embodiments, the ratio of 2,4-hexadienoic acid to water is 1:10 to 20.

[0080] In some of these embodiments, 2,4-hexadienoic acid and water are reacted under reflux conditions.

[0081] In some embodiments, the reaction time of 2,4-hexadienoic acid and water is 0.5 hours to 5 hours, preferably 1 hour to 3 hours.

[0082] In some embodiments of the present invention, the application of the modified polylactic acid oligomer is also provided in the preparation of antibacterial agents.

[0083] In some embodiments of the present invention, the application of the modified polylactic acid oligomers in the preparation of preservatives is also provided.

[0084] In some embodiments of the present invention, the application of the modified polylactic acid oligomers in the preparation of acaricides is also provided.

[0085] In some embodiments of the present invention, an antibacterial agent is also provided, the active ingredient of which contains the modified polylactic acid oligomer described in the present invention.

[0086] In some embodiments of the present invention, an anti-preservative is also provided, the active ingredient of which contains the modified polylactic acid oligomer described in the present invention.

[0087] In some embodiments of the present invention, an acaricide is also provided, the active ingredient of which contains the modified polylactic acid oligomer described in the present invention.

[0088] In some embodiments of the present invention, the use of the modified polylactic acid oligomer or the antibacterial agent in the preparation of antibacterial products is also provided.

[0089] In some embodiments of the present invention, the present invention also provides the application of the modified polylactic acid oligomer or the preservative in the preparation of preservative products.

[0090] In some embodiments of the present invention, the present invention also provides the application of the modified polylactic acid oligomer or the acaricide in the preparation of acaricide products.

[0091] The bacteria can be bacteria (such as Staphylococcus aureus, Escherichia coli, etc.) or fungi (such as Candida albicans, etc.).

[0092] The antibacterial products include antibacterial pharmaceutical preparations (such as microneedles), textiles, paper towels, laundry detergent, food additives, food packaging materials, dyes, dyeing and finishing agents, paints, coatings, surface coating materials, agricultural products, or livestock products, etc.; the preservative products include preservative pharmaceutical preparations, textiles, paper towels, laundry detergent, food additives, or food packaging materials, etc.; the mite-removing products are textiles or paper towels that can remove mites, etc.

[0093] In some embodiments of the present invention, the present invention also provides an antibacterial method, comprising: treating the product requiring antibacterial treatment with the modified polylactic acid oligomer or the antibacterial agent described in the present invention.

[0094] In some embodiments of the present invention, the present invention also provides a method for corrosion prevention, comprising: treating the product requiring corrosion prevention with the modified polylactic acid oligomer or the preservative described in the present invention.

[0095] In some embodiments of the present invention, the present invention also provides a method for removing mites, comprising: treating the product requiring mite removal with the modified polylactic acid oligomer or the mite-removing agent described in the present invention.

[0096] The bacteria can be bacteria (such as Staphylococcus aureus, Escherichia coli, etc.) or fungi (such as Candida albicans, etc.).

[0097] The products requiring antibacterial properties include pharmaceutical preparations (such as microneedles), textiles, paper towels, laundry detergent, food additives, food packaging materials, dyes, dyeing and finishing agents, paints, coatings, surface coating materials, agricultural supplies, or livestock supplies, etc.; the products requiring preservation include pharmaceutical preparations, textiles, paper towels, laundry detergent, food additives, or food packaging materials, etc.; the products requiring mite removal include textiles or paper towels, etc.

[0098] The modified polylactic acid oligomer of the present invention can be used alone or in combination with other antibacterial agents, preservatives or acaricides. It can also be used to modify or transform other antibacterial materials. It can also be used as an active ingredient and combined with other additives, additives, auxiliary substances, etc. to make antibacterial materials of various forms or types for use in the fields of medicine, medical materials, textiles, hygiene products, environment, food, food packaging, dyeing and finishing auxiliaries, paints, surface coatings, plastics and agricultural products.

[0099] The present invention will be further described in detail below with reference to specific embodiments.

[0100] Example 1: Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0101] (1) Preparation of 5-hydroxy-2-hexenoic acid

[0102] 20 g of 2,4-hexadienoic acid and 200 g of water were added to a 500 ml round-bottom flask. While stirring, concentrated sulfuric acid was added to adjust the pH of the solution to 2.0–2.5. The mixture was heated under reflux at atmospheric pressure for 2 hours. After cooling to room temperature, a small amount of sodium hydroxide was added to adjust the pH to 3–3.5. The solution was filtered to obtain 19.8 g of crystalline hydroxylated product (i.e., 5-hydroxy-2-hexadienoic acid), with a yield of 85%. Its infrared and mass spectrometry data are shown in Figures 1 and 2.

[0103] (2) Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0104] The 5-hydroxy-2-hexenoic acid prepared in step (1) was mixed with lactic acid monomer at a molar ratio of 1:1, and 5 times the weight of water (5 times the total weight of 5-hydroxy-2-hexenoic acid and lactic acid) was added. The mixture was heated under reflux for 2 hours, and then stirred and heated under nitrogen protection at a temperature of 200°C and a pressure of 2000Pa for 4 hours for polymerization reaction. The mixture was then cooled to room temperature to obtain the poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer.

[0105] After the reaction was completed, the temperature was lowered to room temperature, and all reaction products were collected. The liquid chromatography-mass spectrum was obtained by mass spectrometry, as shown in Figure 3. This 2,4-hexadienoic acid copolymer-modified polylactic acid oligomer (poly(lactic acid-5-hydroxy-2-hexadienoic acid) copolymer oligomer) has both repeating units of lactic acid monomers with a molecular weight of 72 (641, 713, 785, 857) and repeating units of 2,4-hexadienoic acid monomers with a molecular weight of 112 (417, 529, 641). Its structural formula is shown in formula (I) below, with an average degree of polymerization of 7-8, n = 4-5, and m = 3-4.

[0106] Example 2: Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0107] The preparation method of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer provided in this embodiment differs from that in Example 1 in that the molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid monomer is 1:2, while all other aspects are the same as in Example 1.

[0108] Example 3: Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0109] The preparation method of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer provided in this embodiment differs from that in Example 1 in that the molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid monomer is 1:3, while all other aspects are the same as in Example 1.

[0110] Example 4: Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0111] The preparation method of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer provided in this embodiment differs from that in Example 1 in that the polymerization time in step (2) is 1 hour, while the rest is the same as in Example 1.

[0112] Example 5: Preparation of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers

[0113] The preparation method of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer provided in this embodiment differs from that in Example 1 in that the polymerization time in step (2) is 16 hours, while the rest is the same as in Example 1. Its mass spectrum and infrared spectrum are shown in Figure 4 and Figure 5, respectively.

[0114] Comparative Example 1: Preparation of Polylactic Acid Oligomers

[0115] Lactic acid monomers were stirred and heated at 200℃ and 2000 Pa under nitrogen protection for 4 hours. After cooling to room temperature, all reaction products were collected to obtain polylactic acid oligomers. Their liquid chromatography-mass spectrum is shown in Figure 6, with an average degree of polymerization of 4–5 and a molecular weight of 72 for repeating units.

[0116] Preparation of Comparative Example 2 Poly(5-hydroxy-2-hexenoic acid) oligomers

[0117] Under acidic conditions of pH 2-3, at 200℃ and a pressure of 2000 Pa, and under nitrogen protection, the 5-hydroxy-2-hexenoic acid monomer was stirred and heated for 4 hours. After cooling to room temperature, all reaction products were collected to obtain polylactic acid oligomers. The mass spectrum and infrared spectrum of the product are shown in Figures 7 and 8.

[0118] Preparation of Comparative Example 3 Poly(lactic acid-gluconic acid) copolymer oligomers

[0119] Gluconic acid and lactic acid monomers were mixed in a 1:1 molar ratio, and 5 times their weight of water were added. The mixture was heated under reflux for 2 hours, and then stirred and heated under nitrogen protection at a temperature of 200°C and a pressure of 2000Pa for 4 hours to polymerize. The mixture was then cooled to room temperature, and all reaction products were collected to obtain the poly(lactic acid-gluconic acid) copolymer oligomer.

[0120] Comparative Example 4: Preparation of poly(lactic acid-3-carboxy-3-hydroxyglutaric acid) copolymer oligomers

[0121] 3-Carboxy-3-hydroxyglutaric acid and lactic acid monomer were mixed in a 1:1 molar ratio, and 5 times the weight of water was added. The mixture was heated under reflux for 2 hours, and then stirred and heated under nitrogen protection at a temperature of 200°C and a pressure of 2000 Pa for 4 hours to polymerize. The mixture was then cooled to room temperature, and all reaction products were collected to obtain the poly(lactic acid-3-carboxy-3-hydroxyglutaric acid) copolymer oligomer.

[0122] Preparation of Comparative Example 5 Poly(lactic-3-hydroxybutyric acid) Co-oligomers

[0123] 3-hydroxybutyric acid and lactic acid monomers were mixed in a 1:1 molar ratio, and 5 times the weight of water was added. The mixture was heated under reflux for 2 hours, and then stirred and heated under nitrogen protection at a temperature of 200°C and a pressure of 2000Pa for 4 hours to polymerize. The mixture was then cooled to room temperature, and all reaction products were collected to obtain the poly(lactic acid-3-hydroxybutyric acid) copolymer oligomer.

[0124] Example 6 Antibacterial Performance Test

[0125] This embodiment tests the antibacterial properties of the oligomers prepared in Examples 1-5 and Comparative Examples 1-5.

[0126] (1) The oligomers prepared in Examples 1-3 and Comparative Examples 1-5 were tested for their antibacterial activity against Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) according to ASTM E2783-22. The results of the antibacterial performance are shown in Tables 1-2.

[0127] Table 1. Antibacterial properties of oligomers prepared with different monomer ratios

[0128] Table 2 Antibacterial properties of different polyhydroxyalkanoic acids

[0129] Table 1 shows that poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers exhibit excellent antibacterial activity against Staphylococcus aureus and Escherichia coli. Furthermore, the antibacterial performance decreases with increasing proportion of lactic acid copolymer in the copolymer, indicating that copolymerization modification of polylactic acid oligomers with 5-hydroxy-2-hexenoic acid copolymers can improve their antibacterial properties. Moreover, the antibacterial performance of poly(5-hydroxy-2-hexenoic acid) oligomers is worse than that of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers, suggesting that copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid has a synergistic antibacterial effect, significantly improving the antibacterial performance of either polylactic acid oligomers or poly(5-hydroxy-2-hexenoic acid) oligomers.

[0130] As can be seen from Table 2, poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers have better antibacterial properties than other types of modified polylactic acid oligomer materials.

[0131] (2) The antibacterial activity of the oligomers prepared in Examples 1-5 and Comparative Examples 1-5 against Candida albicans (ATCC 10231) was tested using the method ASTM E2149-20.

[0132] The test results are shown in Tables 3-5.

[0133] Table 3. Viscosity, degree of polymerization, and antibacterial properties of oligomers prepared at different polymerization times.

[0134] Note: 0 hours in the table refers to the mixture of 5-hydroxy-2-hexenoic acid and lactic acid monomer in a 1:1 molar ratio, i.e., the raw material mixture that has not undergone reaction.

[0135] In the polymerization reaction, the polymerization time has a significant impact on the viscosity, degree of polymerization, and antibacterial properties of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers. As shown in Table 2, the viscosity and degree of polymerization increase with the extension of polymerization time, while the antibacterial properties against Candida albicans (fungi) first increase and then decrease with the extension of polymerization time. The poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer with a polymerization time of 4 hours has the best antibacterial properties.

[0136] Table 4 shows the viscosity, degree of polymerization, and antibacterial properties of oligomers prepared with different monomer ratios.

[0137] Table 5. Antibacterial activity of different polyhydroxyalkanoates against Candida albicans

[0138] Example 7: Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in tissue-engineered microneedles

[0139] The polymerization reaction was carried out for 16 hours according to the preparation method of Example 5 to obtain a solid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer. The obtained solid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer product was poured into a mold of tissue engineering microneedles, compacted, and frozen in a refrigerator for 18 hours. After that, it was carefully removed from the microneedle mold (A in Figure 9), and its hardness was tested to be 68 (Shore hardness C, -10°C). The mass spectrum was obtained by mass spectrometry, as shown in Figure 4. The degree of polymerization of the solid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer is about 6 to 30, and the molecular weights of the repeating units are 72 and 112.

[0140] Polymerization was carried out for 16 hours according to the preparation method of Comparative Example 1 to obtain solid polylactic acid oligomers. The obtained solid polylactic acid oligomer product was poured into a mold for tissue engineering microneedles, compacted, and frozen in a refrigerator for 18 hours. After that, it was carefully removed from the microneedle mold (B in Figure 9), and its hardness was tested to be 85 (Shore hardness C, -10℃). The mass spectrum was obtained by mass spectrometry, as shown in Figure 10. The degree of polymerization of the solid polylactic acid oligomer is about 3 to 42, and the molecular weight of the repeating unit is 72.

[0141] Treatment of infected wounds with microneedles: Before modeling, the animals were depilated. Using a skin harvesting tool, two 1 cm diameter wounds were made on the left and right sides of the back of the experimental SD rats, maintaining a certain distance between the wounds to ensure they do not interfere with each other. Staphylococcus aureus (ATCC 6538) was diluted with physiological saline to the working concentration for infection. After the infected wounds were dried (approximately 30 minutes), the wounds were covered with microneedles.

[0142] Observation of the wound revealed that after one day, both polylactic acid (PLA) oligomer microneedles and poly(lactic-5-hydroxy-2-hexenoic acid) copolymer oligomer microneedles melted and were absorbed by the skin. The poly(lactic-5-hydroxy-2-hexenoic acid) copolymer oligomer microneedles melted and were absorbed more quickly, resulting in a relatively dry wound that healed more easily. In contrast, the PLA oligomer microneedles melted more slowly and were not fully absorbed by the skin, leaving the wound slightly moist (as shown in Figure 11). This indicates that both types of microneedles soften at body temperature (37°C), facilitating tissue absorption after drug administration. The poly(lactic-5-hydroxy-2-hexenoic acid) copolymer oligomer is less hard and more easily decomposed than the PLA oligomer.

[0143] Figure 12 shows the wound healing process after treatment with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers.

[0144] After 11 days, the wounds treated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers gradually scabbed over and healed, while the untreated mice died from systemic infection and sepsis due to high bacterial load in the wounds.

[0145] Example 8: Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in antibacterial textiles

[0146] The poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the polylactic acid oligomer prepared in Comparative Example 1 were used to perform antibacterial finishing on pure cotton nonwoven fabrics, with an application rate of 2% (relative to fabric weight). The antibacterial finishing process was a pad-drying process. The specific experimental steps are as follows:

[0147] Prepare a 2% concentration oligomer aqueous solution and pour it into the padding tank. Cut pure cotton woven fabric into 20cm*20cm pieces and immerse them in the padding tank. Pass the fabric through the rollers of a small padding machine (set the liquid absorption rate to 100%). After the rollers apply pressure, the oligomer can be evenly distributed on the pure cotton nonwoven fabric. After drying at 120℃ for 5 minutes, the antibacterial pure cotton nonwoven fabric is prepared.

[0148] Antibacterial pure cotton nonwoven fabric was tested against Escherichia coli (ATCC 25922) for 2 hours and 4 hours according to standard WS / T 650-2019. The antibacterial cotton nonwoven fabric treated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer showed an antibacterial rate of 56.1% at 2 hours, indicating a certain antibacterial effect, and an antibacterial rate of 90.5% at 4 hours, achieving a good antibacterial effect. The pure cotton nonwoven fabric treated with unmodified polylactic acid oligomer showed an antibacterial rate of only 14.3% at 2 hours and 60.9% at 4 hours. This indicates that the antibacterial effect of unmodified polylactic acid oligomer is relatively poor, while the antibacterial cotton nonwoven fabric treated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer has higher antibacterial efficiency and can shorten the time to achieve the same level of antibacterial effect.

[0149] The hand feel of the finished pure cotton nonwoven fabric was evaluated, and the evaluation criteria were divided into 1 to 5 levels, with level 5 being the best, smooth and not sticky; level 4 being smooth and slightly damp; level 3 being moderately damp and slightly frizzy; level 2 being relatively damp and frizzy; and level 1 being the worst, with severe and obvious dampness and frizz.

[0150] Table 6. Evaluation results of the hand feel of the finished pure cotton nonwoven fabric

[0151] As can be seen from Table 6, the antibacterial pure cotton nonwoven fabric obtained by treating with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer has a smoother and more comfortable feel compared with the pure cotton nonwoven fabric treated with unmodified polylactic acid oligomer.

[0152] Example 9: Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in washable and antibacterial textiles.

[0153] The poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the polylactic acid oligomer prepared in Comparative Example 1 were used to perform antibacterial finishing on pure cotton woven fabrics. The dosage was 5% (relative to the fabric weight). The antibacterial finishing process was a pad-drying process at a temperature of 120 degrees Celsius for 5 minutes. The specific experimental steps are as follows: The pure cotton woven fabric was cut into two pieces of fabric measuring 20cm*20cm. The two pieces were padded with aqueous solutions of the poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the polylactic acid oligomer prepared in Comparative Example 1 (oligomer:water = 1:10). The fabrics were then dried in a setting machine at 120 degrees Celsius for 5 minutes. The fabric weight increased by about 5%, resulting in the antibacterial finished pure cotton nonwoven fabric.

[0154] Antibacterial treatment of pure cotton nonwoven fabric was performed on Staphylococcus aureus (ATCC 6538) according to the method shown in Table 7.

[0155] Table 7 Wash resistance and antibacterial test of pure cotton woven fabrics

[0156] As shown in Table 7, the antibacterial pure cotton woven fabric treated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer exhibits excellent antibacterial properties and good wash stability, maintaining a very high antibacterial rate even after 50 washes. In contrast, the pure cotton woven fabric treated with unmodified polylactic acid oligomer has only moderate antibacterial properties and poor wash stability, with an antibacterial rate of 0 after 50 washes. Therefore, the antibacterial pure cotton woven fabric treated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer demonstrates better antibacterial properties and better wash stability compared to the pure cotton woven fabric treated with unmodified polylactic acid oligomer.

[0157] Example 10: Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in coatings

[0158] The poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the unmodified polylactic acid oligomer prepared in Comparative Example 1 were mixed with sodium polyacrylate dispersant at a mass ratio of 1:3. The resulting mixture was then added to a transparent water-based paint (composed of sodium polyacrylate and water-based HDI curing agent at a mass ratio of 10:1) at a weight of 20 times the weight of the mixture. The mixture was stirred and dispersed evenly to obtain an antibacterial water-based paint.

[0159] The obtained antibacterial water-based paint was sprayed onto the wood panels (using a spray gun, 70 ml per square meter, air pressure 2-3 bar), and after drying, the antibacterial properties of the wood panels against Escherichia coli (ATCC 25922) were tested according to ASTM E2149-20.

[0160] The results showed that the sterilization rates of wood boards coated with poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers and wood boards coated with unmodified polylactic acid oligomers against Escherichia coli were 99.9% and 0%, respectively. This indicates that poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers have excellent antibacterial properties, and adding a low content to water-based paint can achieve excellent sterilization effects. However, when unmodified polylactic acid oligomers are added to water-based paints at a low content, the resulting water-based paint coating cannot achieve a significant antibacterial effect.

[0161] Example 11: Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in mite control.

[0162] The liquid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the unmodified liquid polylactic acid oligomer prepared in Comparative Example 1 were mixed with pillow cotton at a ratio of 5% relative to the weight of the fabric to prepare antibacterial fillings.

[0163] According to the 24-hour mite repellency rate of antibacterial fillers tested according to GB / T 24253, the test results showed that the mite repellency rates of antibacterial fillers containing poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers and antibacterial fillers containing unmodified polylactic acid oligomers were 71% and 30%, respectively, indicating that poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers have a better mite repellency effect than unmodified polylactic acid oligomers.

[0164] Example 12 Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers in laundry detergent

[0165] The liquid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the unmodified liquid polylactic acid oligomer prepared in Comparative Example 1 were added to ordinary laundry detergent (mainly composed of sodium dodecylbenzenesulfonate, alcohol ethoxysulfate, potassium laurate and water) at 5% and 10% (relative to the weight of ordinary laundry detergent), respectively, to obtain antibacterial laundry detergent.

[0166] The antibacterial activity of the antibacterial laundry detergent against Escherichia coli (ATCC 25922) was tested according to QB / T 2738 (antibacterial; simulation method), and the results are shown in Table 8.

[0167] Table 8. Antibacterial properties of antibacterial laundry detergents

[0168] As can be seen from Table 8, compared with ordinary laundry detergent and laundry detergent with added polylactic acid oligomers, laundry detergent with added poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers has a higher antibacterial rate.

[0169] Example 13 Application of poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer in paper towels

[0170] The liquid poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomer prepared in Example 1 and the unmodified liquid polylactic acid oligomer in Comparative Example 1 were added at amounts of 2.5%, 5%, and 7.5% (relative to the weight of the paper towel), respectively, and applied to ordinary paper towels (composed of pure cotton, three-layer thin paper towels) using a pad-drying process (specific experimental method as in Example 8) at a temperature of 120 degrees Celsius for 5 minutes to obtain antibacterial paper towels.

[0171] According to the United States Pharmacopeia (USP) 51 antimicrobial efficiency, the 28-day antimicrobial performance of the obtained antibacterial tissues against Escherichia coli (ATCC 25922) was tested, and the results are shown in Table 9 below.

[0172] Table 9. Antibacterial properties of antibacterial paper towels

[0173] As can be seen from Table 9, compared with ordinary paper towels and paper towels with added polylactic acid oligomers, paper towels with added poly(lactic acid-5-hydroxy-2-hexenoic acid) copolymer oligomers have better anti-corrosion effects and can meet the industry requirements of <200 CFU / g microbial colony count.

[0174] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A modified polylactic acid oligomer having the structure shown in formula (I), in, n and m are each independently selected from integers from 1 to 100.

2. The modified polylactic acid oligomer according to claim 1, characterized in that, n is selected from: integers from 1 to 50; m is selected from: integers from 1 to 50.

3. The modified polylactic acid oligomer according to claim 2, characterized in that, n is selected from: integers from 1 to 20; m is selected from: integers from 1 to 20.

4. The modified polylactic acid oligomer according to claim 3, characterized in that, n is selected from integers from 1 to 12; m is selected from integers from 1 to 12.

5. The modified polylactic acid oligomer according to claim 4, characterized in that, n is selected from integers from 2 to 8; m is selected from integers from 2 to 8.

6. The modified polylactic acid oligomer according to claim 5, characterized in that, n is selected from integers of 4 to 5; m is selected from integers of 3 to 4.

7. A modified polylactic acid oligomer, characterized in that, The modified polylactic acid oligomer is obtained by copolymerization of 5-hydroxy-2-hexenoic acid and lactic acid, and has a number average molecular weight of 100 to 10,000.

8. The modified polylactic acid oligomer according to claim 7, characterized in that, The molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid is 1:0.5 to 3.

9. The modified polylactic acid oligomer according to claim 8, characterized in that, The molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid is 1:0.8 to 2.

10. The modified polylactic acid oligomer according to claim 9, characterized in that, The molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid is 1:0.9 to 1.

5.

11. The modified polylactic acid oligomer according to claim 10, characterized in that, The molar ratio of 5-hydroxy-2-hexenoic acid to lactic acid is 1:0.9 to 1.

2.

12. The modified polylactic acid oligomer according to any one of claims 7-11, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 200–3000.

13. The modified polylactic acid oligomer according to any one of claims 12, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 200–1100.

14. The modified polylactic acid oligomer according to any one of claims 13, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 200–800.

15. The modified polylactic acid oligomer according to any one of claims 14, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 300–800.

16. The modified polylactic acid oligomer according to claim 15, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 400–800.

17. The modified polylactic acid oligomer according to claim 16, characterized in that, The number-average molecular weight of the modified polylactic acid oligomer is 600-700.

18. A method for preparing the modified polylactic acid oligomer according to any one of claims 1-17, characterized in that, Includes the following steps: Under inert gas protection, 5-hydroxy-2-hexenoic acid and lactic acid undergo a copolymerization reaction at a temperature of 100℃~300℃ and a pressure of 5Pa~5MPa to obtain the modified polylactic acid oligomer.

19. The method for preparing the modified polylactic acid oligomer according to claim 18, characterized in that, The process includes the following steps: mixing the 5-hydroxy-2-hexenoic acid and lactic acid, adding water, heating under reflux for 1 to 3 hours, and then performing a copolymerization reaction under inert gas protection at a temperature of 100°C to 300°C and a pressure of 5 Pa to 5 MPa to obtain the modified polylactic acid oligomer.

20. The method for preparing the modified polylactic acid oligomer according to claim 19, characterized in that, The amount of water added is 4 to 8 times the total weight of 5-hydroxy-2-hexenoic acid and lactic acid.

21. The method for preparing the modified polylactic acid oligomer according to any one of claims 18-20, characterized in that, The temperature is 150℃~250℃; and / or, The pressure is 1000 Pa to 3000 Pa; and / or, The copolymerization reaction time is from 0.01 hours to 72 hours.

22. The method for preparing the modified polylactic acid oligomer according to claim 21, characterized in that, The temperature is 180℃~220℃.

23. The method for preparing the modified polylactic acid oligomer according to claim 21, characterized in that, The pressure is 1500Pa to 2500Pa.

24. The method for preparing the modified polylactic acid oligomer according to claim 21, characterized in that, The copolymerization reaction time is 0.5 hours to 20 hours.

25. The method for preparing the modified polylactic acid oligomer according to claim 24, characterized in that, The copolymerization reaction time is 0.5 hours to 16 hours.

26. [Amended according to Rule 26, 09.01.2026] The method for preparing the modified polylactic acid oligomer according to claim 25 is characterized in that, The copolymerization reaction takes 0.8 to 8 hours.

27. The method for preparing the modified polylactic acid oligomer according to claim 26, characterized in that, The copolymerization reaction takes 1 to 7 hours.

28. The method for preparing the modified polylactic acid oligomer according to claim 27, characterized in that, The copolymerization reaction takes 2 to 6 hours.

29. The method for preparing the modified polylactic acid oligomer according to claim 28, characterized in that, The copolymerization reaction takes 3 to 5 hours.

30. The method for preparing the modified polylactic acid oligomer according to any one of claims 18-20, characterized in that, It also includes the preparation of 5-hydroxy-2-hexenoic acid, the method for preparing 5-hydroxy-2-hexenoic acid comprising the following steps: Under acidic conditions, 2,4-hexadienoic acid reacts with water to yield 5-hydroxy-2-hexadienoic acid.

31. The method for preparing the modified polylactic acid oligomer according to claim 30, characterized in that, The pH of the acidic conditions is 1–4; and / or, The mass ratio of 2,4-hexadienoic acid to water is 1:10-20; and / or, 2,4-Hexadienoic acid and water react under reflux conditions; and / or, The reaction time of 2,4-hexadienoic acid and water is 0.5 to 5 hours.

32. The use of the modified polylactic acid oligomer according to any one of claims 1-17 in the preparation of antibacterial agents, preservatives, or acaricides.

33. An antibacterial agent, preservative, or acaricide, characterized in that, Its active ingredient contains the modified polylactic acid oligomer as described in any one of claims 1-17.

34. The use of the modified polylactic acid oligomer according to any one of claims 1-17 or the antibacterial agent according to claim 33 in the preparation of antibacterial products; or, The use of the modified polylactic acid oligomer according to any one of claims 1-17 or the preservative according to claim 33 in the preparation of preservative products; or The use of the modified polylactic acid oligomer according to any one of claims 1-17 or the acaricide according to claim 33 in the preparation of acaricide products.

35. The application according to claim 32 or 34, characterized in that, The bacteria can be bacteria or fungi.

36. The application according to claim 35, characterized in that, The bacteria are Staphylococcus aureus and Escherichia coli.

37. The application according to claim 35, characterized in that, The fungus in question is Candida albicans.

38. The application according to claim 34, characterized in that, The antibacterial products include antibacterial pharmaceutical preparations, textiles, paper towels, laundry detergents, food additives, food packaging materials, dyes, dyeing and finishing agents, paints, coatings, surface coating materials, agricultural products, or livestock products. The preservative products are pharmaceutical preparations, textiles, paper towels, laundry detergents, food additives, or food packaging materials that can prevent corrosion. The mite-removing product is a textile or paper towel that can remove mites.

39. A method for antibacterial, antiseptic, or mite-removing purposes, characterized in that, include: The product requiring antibacterial treatment is treated with the modified polylactic acid oligomer according to any one of claims 1-17 or the antibacterial agent according to claim 33; Alternatively, the product requiring preservation may be treated with the modified polylactic acid oligomer as described in any one of claims 1-17 or the preservative as described in claim 33; Alternatively, the product requiring mite removal may be treated with the modified polylactic acid oligomer as described in any one of claims 1-17 or the mite remover as described in claim 33.

40. The method for antibacterial, antiseptic, or mite removal according to claim 39, characterized in that, The bacteria can be bacteria or fungi.

41. The method for antibacterial, antiseptic, or mite removal according to claim 40, characterized in that, The bacteria are Staphylococcus aureus and Escherichia coli; And / or, the fungus is Candida albicans.

42. The method for antibacterial, antiseptic, or mite removal according to any one of claims 39-41, characterized in that, The products requiring antibacterial properties include pharmaceutical preparations, textiles, paper towels, laundry detergents, food additives, food packaging materials, dyes, dyeing and finishing agents, paints, coatings, surface coating materials, agricultural supplies, or livestock supplies. The products requiring preservation include pharmaceutical preparations, textiles, paper towels, laundry detergent, food additives, or food packaging materials. The products that require mite removal are textiles or paper towels.

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