Poly (aromatic ester-ether)-based biodegradable material polyester and preparation method thereof

Abstract

The invention relates to a poly (aromatic ester-ether)-based biodegradable material polyester and a preparation method thereof. The method comprises the following steps: firstly, taking 3-allyl-4-hydroxybenzoate and cyclohexyl-1, 4-dimethyl alcohol monovinyl ether as monomers, and synthesizing poly (aromatic ester-ether) dihydric alcohol through emulsion polymerization; and carrying out esterification and polycondensation on the polyester, organic dibasic acid, 2, 4-methyl dihydroxybenzoate, a polyfunctional cross-linking agent and a stabilizer under the action of a catalyst to prepare the novel poly (aromatic ester-ether)-based biodegradable material polyester. According to the method, traditional 1, 4-butanediol is replaced with methyl 2, 4-dihydroxybenzoate, so that cyclization side reaction is effectively inhibited, tetrahydrofuran is prevented from being generated, and consistency and stability of product quality are guaranteed. The obtained polyester material has excellent biodegradability and mechanical tensile property, and is suitable for plastic products such as mulching films, packaging bags and the like which need to be completely degraded and have enough mechanical strength requirements.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a poly(aromatic ester-ether)-based biodegradable material polyester and its preparation method. Background Technology

[0002] According to statistics, China's plastic product output reached 81.84 million tons in 2019, a year-on-year increase of 3.91%. However, a large number of plastic products, once used and discarded, cannot be degraded or recycled, causing significant white pollution, a problem that has become a major concern for the entire society. In response to this issue, my country issued the "Opinions on Further Strengthening the Governance of Plastic Pollution," which explicitly encourages the research and development and production of environmentally degradable film coverings and product packaging. In recent years, the development of low-cost biodegradable materials has become a trend in the field of environmental protection materials.

[0003] Currently, polybutylene adipate terephthalate (PBAT), as a novel biodegradable copolyester, is mainly produced through esterification reactions using terephthalic acid or terephthalate glycol ester, butanediol, and adipic acid as raw materials. PBAT is readily degraded by microorganisms and poses no environmental harm, thus it has been widely used in packaging, medical, and film industries. However, during the production process of PBAT... Butanediol undergoes a cyclization reaction, producing tetrahydrofuran (THF) as a byproduct. This not only reduces the yield and increases production costs, but also requires the recovery of this byproduct through a distillation column, increasing energy consumption and further raising production costs. More seriously, the amount of this byproduct produced varies from batch to batch, resulting in poor reproducibility of the PBAT material and unstable product quality.

[0004] In the prior art, some solutions have been proposed to address the problem of excessive tetrahydrofuran byproducts during the preparation of PBAT. For example, CN111087593 discloses a catalyst composition for inhibiting THF formation and resistant to hydrolysis, its preparation method, and its application. This method reduces the amount of THF byproducts by employing a novel catalyst composition consisting of a highly catalytically active, hydrolysis-resistant titanium compound, a reaction product of an alcohol containing at least two hydroxyl groups, a hydroxycarboxylic acid, and a base. This method is suitable for reducing THF generation during the synthesis of polybutylene terephthalate (PBT) and PBAT. However, results show that the amount of THF generated (according to a 1,4...) is... The amount of butanediol added (calculated) only decreased from 21% to 18%, which is still very high. CN 113773478 B provides a poly(carbonate) Ether-based biodegradable polyesters and their preparation methods. Using poly(carbonate) Ether diols, aromatic dicarboxylic acids (esters), 1,6 adipic acid and 1,4 Butylene glycol is used as a reactant, and poly(carbonate) is introduced. (ether) diol, greatly reducing 1,4 The amount of butanediol used significantly reduces the probability of tetrahydrofuran byproduct formation. Summary of the Invention

[0005] In view of this, the present invention aims to provide a poly(aromatic ester-ether)-based biodegradable polyester material and its preparation method. The method first synthesizes a poly(aromatic ester-ether) diol using 3-allyl-4-hydroxybenzoate and cyclohexyl-1,4-diethanol monovinyl ether as monomers through emulsion polymerization. Subsequently, using this copolymer as a precursor, it undergoes esterification and condensation polymerization with an organic diacid, a multifunctional crosslinking agent, and a stabilizer under the action of a catalyst to prepare the poly(aromatic ester-ether)-based biodegradable polyester material. This method fundamentally avoids the generation of the byproduct tetrahydrofuran (THF), while endowing the material with excellent biodegradability and mechanical properties, providing an effective solution to the problem of "white pollution"—the inability to degrade and recycle large quantities of discarded plastic products.

[0006] The objective of this invention can be achieved through the following methods: This invention provides a poly(aromatic ester-ether)-based biodegradable polyester material, which is prepared by the following method: (1) Poly(aromatic ester-ether) diol was synthesized by emulsion polymerization using 3-allyl-4-hydroxybenzoate and cyclohexyl-1,4-diethanol monovinyl ether as monomers; (2) The poly(aromatic ester-ether) diol synthesized in step (1) is used as raw material, along with organic dicarboxylic acid, multifunctional crosslinking agent, stabilizer and methyl 2,4-dihydroxybenzoate. After esterification and polycondensation reaction, poly(aromatic ester-ether) based biodegradable material polyester is prepared.

[0007] The poly(aromatic ester-ether)-based biodegradable polyester of the present invention is a copolymer obtained by polymerization reaction of 3-allyl-4-hydroxybenzoate, cyclohexyl-1,4-diethanol monovinyl ether and organic dicarboxylic acid.

[0008] As one embodiment of the present invention, the 3-allyl-4-hydroxybenzoic acid ester includes one or more of methyl 3-allyl-4-hydroxybenzoate, ethyl 3-allyl-4-hydroxybenzoate, propyl 3-allyl-4-hydroxybenzoate, isopropyl 3-allyl-4-hydroxybenzoate, butyl 3-allyl-4-hydroxybenzoate, pentyl 3-allyl-4-hydroxybenzoate, hexyl 3-allyl-4-hydroxybenzoate, and octyl 3-allyl-4-hydroxybenzoate.

[0009] Preferably, 3-allyl-4-hydroxybenzoate is methyl 3-allyl-4-hydroxybenzoate.

[0010] As one embodiment of the present invention, the organic dicarboxylic acid is one or more of the C3-C16 straight-chain alkyl dicarboxylic acids. The organic dicarboxylic acids include one or more of 1,3-malonic acid, 1,4-succinic acid, 1,6-adipic acid, 1,7-heptanedic acid, 1,8-octanoic acid, 1,9-azelanoic acid, 1,10-sediic acid, 1,11-undecanediic acid, 1,12-dodecanediic acid, 1,13-tridecanediic acid, 1,14-tetradecanediic acid, 1,15-pentadecanedioic acid, and 1,16-hexadecanediic acid.

[0011] Preferably, the organic dicarboxylic acid is 1,6-adipic acid.

[0012] As one embodiment of the present invention, the number average molecular weight (Mn) of the poly(aromatic ester-ether) based biodegradable material polyester is 75,000 to 93,000.

[0013] This invention also provides a method for preparing a poly(aromatic ester-ether)-based biodegradable material polyester, comprising the following steps: S1. Preparation of poly(aromatic ester-ether) diols: Add deionized water, emulsifier, activator, 3-allyl-4-hydroxybenzoate, cyclohexyl-1,4-diethanol monovinyl ether, molecular weight regulator, and oxygen scavenger to the reactor, stir and mix, cool down and add initiator to carry out polymerization reaction, and finally add terminator and stir to obtain poly(aromatic ester-ether) diol. S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester materials: Poly(aromatic ester-ether) diol, organic diacid, stabilizer, and multifunctional crosslinking agent are added to a reaction vessel, mixed and stirred, and then a catalyst is added after heating to carry out the esterification reaction. After heating, methyl 2,4-dihydroxybenzoate is added to continue the esterification reaction. Then, vacuum decompression is carried out to continue the polycondensation reaction. After the reaction stops, poly(aromatic ester-ether) based biodegradable material polyester is obtained.

[0014] In one embodiment of the present invention, in step S1, before adding the reactants to the reactor, the reactor is purged with an inert gas (nitrogen) 3 to 5 times. The reactor is a 10L stainless steel pressure-resistant reactor with a jacket.

[0015] In one embodiment of the present invention, in step S1, the emulsifier is an emulsifier that is stable in an acidic medium, including one or more of alkyl sulfates, alkyl or aryl sulfonates. The emulsifier includes one or more of potassium rosinate soap, methyl oleate soap, sodium oleate soap, sodium pyrophosphate, fatty acids, disproportionated potassium rosinate, sodium fatty acids, and sodium dodecylbenzene sulfonate. Sodium dodecylbenzene sulfonate is preferred as the emulsifier.

[0016] As one embodiment of the present invention, in step S1, the activator includes one or more of the following: sulfadiazine, ferrous sulfate, tetrasodium EDTA, and sodium iron EDTA.

[0017] In one embodiment of the present invention, in step S1, the molecular weight regulator includes one of tert-decyl thiols, tert-dodecyl thiols, tert-tetradecyl thiols, and tert-hexadecyl thiols. The preferred molecular weight regulator is tert-dodecyl thiols.

[0018] In one embodiment of the present invention, in step S1, the oxygen scavenger includes one of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, and N-isopropylhydroxylamine. Sodium dithionite is preferred as the oxygen scavenger.

[0019] In one embodiment of the present invention, in step S1, the initiator is an organic peroxide, including one or more of dicumyl peroxide (DCP), cumyl hydroperoxide, benzoyl peroxide (BPO), and di-tert-butyl peroxide. Dicumyl peroxide (DCP) is preferred as the initiator.

[0020] In one embodiment of the present invention, in step S1, the terminating agent includes one or more of NaNO2, hydroxylamine sulfate, diethylhydroxylamine, 2,5-pentanebutylquinone, sodium thiosulfate (sodium dimethyl dithiocarbamate), and p-aminoazobenzene. Diethylhydroxylamine is preferred as the terminating agent.

[0021] As one embodiment of the present invention, the amounts of each component in step S1 are as follows: The amount of deionized water used is 400% to 500% of the mass of 3-allyl-4-hydroxybenzoate; The amount of emulsifier used is 4.0% to 6.0% of the mass of 3-allyl-4-hydroxybenzoate; The amount of activator used is 0.3% to 0.6% of the mass of 3-allyl-4-hydroxybenzoate; The mass of cyclohexyl-1,4-diethanol monovinyl ether added is 85% to 95% of the mass of 3-allyl-4-hydroxybenzoate; The amount of molecular weight regulator used is 0.5% to 2.0% of the mass of 3-allyl-4-hydroxybenzoate; The amount of oxygen scavenger used is 0.03% to 0.07% of the mass of 3-allyl-4-hydroxybenzoate; The amount of initiator used is 0.02% to 0.21%, preferably 0.08% to 0.15%; The amount of the terminator is 1.0% to 2.0% of the mass of 3-allyl-4-hydroxybenzoate.

[0022] In one embodiment of the present invention, in step S1, cooling means lowering the temperature to 10.0 to 14.0°C.

[0023] As one embodiment of the present invention, in step S1 of the polymerization reaction, when the conversion rate of 3-allyl-4-hydroxybenzoate monomer reaches 96% to 98%, a terminator is added.

[0024] In one embodiment of the present invention, in step S1, the stirring time after adding the terminator is 10-20 minutes. After stirring, the material is discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol.

[0025] In one embodiment of the present invention, in step S2, before adding the reactants to the reactor, the reactor is purged with an inert gas (nitrogen) 3 to 5 times. The reactor is a 10L stainless steel pressure-resistant reactor with a jacket.

[0026] In one embodiment of the present invention, in step S2, the stabilizer is a polar organic compound, including one or more of triethyl phosphite, pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(octadecyl)pentaerythritol diphosphite, pentaerythritol tetrakis[β(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and N,N'-bis(3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine.

[0027] These polar organic compounds can delay or inhibit the polymer oxidation process during polymerization, prevent the formation of polymer byproducts, and avoid product performance degradation.

[0028] In one embodiment of the present invention, in step S2, the multifunctional crosslinking agent is a crosslinking agent having three or more functional groups; the functional groups include one or more of carboxylic acid groups, anhydride groups, and hydroxyl groups. Using the above-mentioned multifunctional crosslinking agent can improve the mechanical properties of polyester products; if the functionality is too low, the mechanical properties of the resulting polyester product will be poor. The multifunctional crosslinking agent includes one of tartaric acid, citric acid, malic acid, trimethylolpropane, trimethylolethane, pentaerythritol, 1,3,5-benzoic acid, 1,2,4-benzoic acid, 1,2,4-benzoic anhydride, 1,2,4,5-benzoic acid, and benzopyrenic acid dianhydride. Trimethylolpropane is preferred as the multifunctional crosslinking agent.

[0029] In one embodiment of the present invention, in step S2, the catalyst comprises one of tetrabutyl titanate, tetraisopropyl titanate, diethylzinc, zinc octanoate, zinc acetate, zinc oxide, and zinc chloride. Tetrabutyl titanate is preferred as the catalyst.

[0030] As one embodiment of the present invention, the amounts of each component in step S2 are as follows: The amount of organic dicarboxylic acid used is 4.0% to 9.0% of the mass of the poly(aromatic ester-ether) diol; The amount of stabilizer used is 0.07% to 0.12% of the mass of the poly(aromatic ester-ether) diol; The amount of the multifunctional crosslinking agent is 0.5% to 2.6% of the mass of the poly(aromatic ester-ether) diol, preferably 0.8% to 1.4%. The amount of catalyst used is 0.15% to 0.35% of the mass of the poly(aromatic ester-ether) diol, preferably 0.18% to 0.23%; The amount of methyl 2,4-dihydroxybenzoate used is 0.6% to 1.0% of the mass of poly(aromatic ester-ether) diol.

[0031] The esterification and polycondensation reactions are carried out by adding 0.15%–0.35% catalyst when the temperature of the polymerization reactor reaches 195–210℃ for 4.5–5.6 hours. Then, the water generated in the reaction is discharged through a water separator. The temperature is then raised to 225–236℃, and 0.6%–1.0% methyl 2,4-dihydroxybenzoate is added to continue the esterification reaction for 1.5–2.6 hours. Subsequently, vacuum pressure is applied, with the negative pressure controlled at 35–40 Pa, and the reaction is carried out for 5.6–6.8 hours. After the acid value reaches 1.8–2.7 mgKOH / g, the reaction is stopped. The reaction product is continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0032] In one embodiment of the present invention, in step S2, the temperature is increased to 195-210°C.

[0033] In one embodiment of the present invention, the esterification reaction in step S2 takes 4.5–5.6 hours. After the esterification reaction, the water generated in the reaction is discharged through a water separator, and then the temperature is further increased.

[0034] In one embodiment of the present invention, in step S2, the temperature is further increased to 225-236°C.

[0035] In one embodiment of the present invention, in step S2, the esterification reaction continues for 1.5 to 2.6 hours.

[0036] In one embodiment of the present invention, in step S2, the vacuum pressure is controlled at 35-40 Pa.

[0037] In one embodiment of the present invention, in step S2, the reaction continues for 5.6 to 6.8 hours after vacuuming and depressurization.

[0038] In one embodiment of the present invention, in step S2, after vacuum decompression and continued reaction, the acid value reaches 1.8–2.7 mg KOH / g, and the reaction is stopped. After the reaction stops, the reaction product is continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0039] In one embodiment of the present invention, in step S1, the stirring speed is 400-500 rpm. In step S2, the stirring speed is 200-300 rpm.

[0040] The poly(aromatic ester-ether) diol used in this invention is more effective than poly(carbonate) diol. Ether diols manifest themselves in three aspects: (1) More thorough inhibition effect and higher product quality stability. In the prior art, poly(carbonate-ether) diols only replace part of 1,4-butanediol, reducing the concentration of reactants that cause cyclization reactions in terms of dosage, thereby greatly reducing the probability of tetrahydrofuran (THF) byproduct formation, but not eliminating the cyclization reaction at its source. In contrast, this invention innovatively introduces methyl 2,4-dihydroxybenzoate to replace the traditional 1,4-butanediol, and synthesizes poly(aromatic ester-ether) diols based on this. This means that in the subsequent esterification and polycondensation stage, 1,4-butanediol is no longer used as a raw material, completely removing the reactants that can undergo cyclization to generate THF from the source of the reaction, achieving complete "effective inhibition" of cyclization side reactions, rather than just "reducing the probability". This fundamentally solves the problem of large fluctuations in the quality stability of the final polyester product due to the different amounts of byproducts generated in different batches of the reaction, thereby ensuring the high consistency and stability of the final polyester product quality, which is more conducive to large-scale industrial production.

[0041] (2) Different molecular structures impart unique effects. Poly(carbonate-ether) diols mainly provide flexible segments (ether bonds) and degradable carbonate bonds, but their molecular skeleton contains aliphatic segments, resulting in a slow degradation rate. Furthermore, they lack the rigid aromatic structure unique to this invention, making it impossible to balance mechanical properties. This invention synthesizes a unique structure that combines both "rigid structure effect" and "group enrichment effect." First, this rigid structure effect originates from aromatic ester structures (such as 3-allyl-4-hydroxybenzoate and the introduced methyl 2,4-dihydroxybenzoate). The rigidity of the aromatic ring can effectively enhance the stiffness of the molecular chain, providing excellent mechanical strength to the material. Second, through molecular design, functional groups such as ester bonds, ether bonds, and hydroxyl groups on the benzene ring, which are easily attacked by microorganisms or enzymes, are introduced into the polymer chain. These functional groups generate a "group enrichment effect" on the chain segments, providing more attack sites for biodegradation, thereby significantly improving the biodegradation efficiency of the material.

[0042] (3) The core technical contradictions they address are different. Existing technologies mainly address the degradability of materials by providing flexible segments (ether bonds) and degradable carbonate bonds. In contrast, this invention utilizes a "rigid aromatic ester structure" to ensure sufficient mechanical properties during the material's service life, while using "enriched active groups" to ensure rapid initiation and degradation under specific environments (such as composting). Through the synergistic effect of the "rigid aromatic ester structure" and "enriched degradation active sites," the technical contradiction of traditional biodegradable materials—"becoming brittle after degradation and difficult to degrade after reinforcement"—is successfully resolved.

[0043] Therefore, compared with poly(carbonate-ether) diol, the poly(aromatic ester-ether) diol used in this invention not only achieves better by-product control and product stability in the production process, but also represents a qualitative leap at the molecular design level. By introducing a unique rigid-active synergistic structure, it significantly improves biodegradability without sacrificing mechanical properties, solving a long-standing technical problem in this field. This is its most significant advancement in technical effect compared to the prior art. Although the prior art also claims good mechanical properties and biodegradability, its technical solution does not explicitly address and resolve this core contradiction at the molecular design level. Its performance improvement is more of an indirect result of substitution than an active design based on a clear structure-performance relationship.

[0044] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) This invention provides a poly(aromatic ester-ether)-based biodegradable polyester. First, 3-allyl-4-hydroxybenzoate and cyclohexyl-1,4-diethanol monovinyl ether are used as monomers to synthesize a poly(aromatic ester-ether) diol via emulsion polymerization. Using this copolymer as a precursor, it undergoes esterification and polycondensation reactions with an organic diacid, methyl 2,4-dihydroxybenzoate, a multifunctional crosslinking agent, and a stabilizer under a catalyst to prepare a novel poly(aromatic ester-ether)-based biodegradable polyester, different from PBAT. This provides a new technical solution for the synthesis of novel biodegradable polyesters. This molecular design successfully synthesizes a novel poly(aromatic ester-ether)-based biodegradable polyester that combines both "group enrichment effect" and "rigid structure effect." This unique chemical structure significantly improves the biodegradability efficiency of the material without sacrificing mechanical properties, successfully solving the technical contradiction of traditional biodegradable materials becoming brittle upon degradation and difficult to degrade upon reinforcement.

[0045] (2) The poly(aromatic ester-ether)-based biodegradable polyester prepared by this invention not only significantly improves the biodegradability of polyester, but also exhibits good mechanical tensile properties. Experimental data show that after 45 days of degradation, the number-average molecular weight (Mn) of the poly(aromatic ester-ether)-based biodegradable polyester shows a significant decrease. At the same time, the degradation rate reaches more than 54% after 30 days of biodegradation, more than 73% after 90 days, and more than 93% after 180 days, showing excellent biodegradability. In addition, the benzene ring structure in its polyaromatic ester exhibits excellent tensile mechanical properties, with a tensile strength of more than 24 MPa, which can fully meet the requirements of plastic products such as mulch film and packaging bags for controllable life cycle, complete degradation and mechanical strength, achieving a perfect unity of high degradation rate and high mechanical properties, and broadening the application boundaries of biodegradable materials.

[0046] (3) In the esterification process of poly(aromatic ester-ether) based biodegradable polyester, this invention innovatively introduces methyl 2,4-dihydroxybenzoate to replace the traditional 1,4-butanediol. This improvement effectively suppresses the occurrence of cyclization side reactions (such as the formation of tetrahydrofuran THF), improves the regularity and purity of the product structure from the reaction source, ensures the high consistency and stability of the final polyester product quality, and is more conducive to large-scale industrial production. Attached Figure Description

[0047] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 The infrared spectrum of the poly(aromatic ester-ether) diol in Example 1 is shown. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions in the embodiments of this invention will be clearly and completely described below in conjunction with the embodiments of this invention. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0049] This invention provides a method for producing a poly(aromatic ester-ether)-based biodegradable polyester material, comprising the following steps: S1. Preparation of poly(aromatic ester-ether) diol: Based on 100% by mass of 3-allyl-4-hydroxybenzoate, first, in a jacketed 10L stainless steel pressure reactor, purge with nitrogen 3-5 times. Then, sequentially add 400%-500% deionized water, 4.0%-6.0% emulsifier, 0.3%-0.6% activator, 100% by mass of 3-allyl-4-hydroxybenzoate, and 85%-95% cyclohexyl-1,4-diethanol monovinyl ether. The molecular weight regulator (0.5%–2.0%) and oxygen scavenger (0.03%–0.07%) are stirred and mixed. The mixture is cooled, and when the temperature of the polymerization reactor reaches 10.0–14.0℃, 0.02%–0.21% of initiator is added to carry out the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reaches 96%–98%, 1.0%–2.0% of terminator is added to the polymerization reactor and stirred for 10–20 minutes. The mixture is then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. S2. Preparation of Poly(Aromatic Ester-Ether)-Based Biodegradable Polyester: Using 100% poly(aromatic ester-ether) diol by mass, first, in a jacketed 10L stainless steel pressure reactor, purge with nitrogen 3-5 times. Under normal pressure, add 100% poly(aromatic ester-ether) diol, 4.0%-9.0% organic diacid, 0.07%-0.12% stabilizer, and 0.5%-2.6% multifunctional crosslinking agent sequentially to the polymerization reactor. Stir and mix, then heat. When the polymerization reactor temperature reaches 195-210℃, add 0.15%-0.35% of the... After the catalyst undergoes esterification for 4.5–5.6 hours, the water generated during the reaction is discharged through a water separator. Then, the temperature is raised to 225–236°C, and 0.6%–1.0% of methyl 2,4-dihydroxybenzoate is added to continue the esterification reaction for another 1.5–2.6 hours. Subsequently, vacuum pressure is applied, with the negative pressure controlled at 35–40 Pa, and the reaction is carried out for 5.6–6.8 hours. After the acid value reaches 1.8–2.7 mg KOH / g, the reaction is stopped, and the reaction product is continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether)-based biodegradable polyester material.

[0050] In this invention, "%" refers to mass percentage.

[0051] Sources of raw materials used in the embodiments and comparative examples of this invention: 3-Allyl-4-hydroxybenzoate methyl ester, 98% purity, Suzhou Lanyun Pharmaceutical Technology Co., Ltd.; Cyclohexyl-1,4-diethanol monovinyl ether, 98% purity, Wuhan Hongde Yuexin Pharmaceutical Technology Co., Ltd. 2,4-Dihydroxybenzoate, 98% purity, Shanghai Mairui Chemical Technology Co., Ltd. Trimethylolpropane, 98% purity, Nanjing Hetian Chemical Co., Ltd. Tetrabutyl titanate, purity 98.5%, Nanjing Tengchuan Technology Co., Ltd. 1,6-Adipic acid, Shandong Banghua Oil & Chemical Co., Ltd.; Dicumyl peroxide (DCP), Lanzhou Additives Factory; All other reagents are commercially available industrial products.

[0052] Analysis and testing methods of this invention: (1) Determination of molecular weight: The determination was performed using a Waters 2414 gel permeation chromatography (GPC) system (USA). Polystyrene standard was used as the calibration curve. The mobile phase was tetrahydrofuran, the column temperature was 40℃, the sample concentration was 1 mg / mL, the injection volume was 50 µL, the elution time was 40 min, and the flow rate was 1 mL / min. -1 . (2) Infrared spectroscopy analysis: Functional group analysis of poly(aromatic ester-ether) diol samples was performed using an infrared spectrometer from Bruke Spectroscopy Instruments, Germany. Samples were dried in a vacuum oven at 100 °C, pressed into pellets using potassium bromide, and acquired at wavenumbers ranging from 400 to 4000 cm⁻¹. -1 .

[0053] (3) Degradation in 45 days: The determination was performed according to the method described in GB / T19277.1-2011.

[0054] (4) Biodegradability test: Referring to GB / T19277.1-2011, this study investigated the final aerobic biodegradation and disintegration capacity of biodegradable polyurethane elastomers under controlled composting conditions. In a 2L test system, polyester was used as the organic carbon source, and the test mixture was aerated at a controlled rate with carbon dioxide-free air. The degradation rate was determined by measuring the amount of carbon dioxide produced.

[0055] (5) Determination of acid value: The determination was performed according to the method described in GB7304-2014.

[0056] (6) Determination of tensile properties: The determination was performed according to the method described in GB1040.1-2018.

[0057] (7) Determination of monomer conversion rate: The monomer was determined by gas chromatography (GC). The monomer was injected into the gas chromatograph, and the remaining monomer content in the solution was quantitatively analyzed using a calibration curve. The final content was then calculated using the following formula: Monomer conversion rate (%) = [1 - (residual monomer mass / initial monomer mass)] × 100%.

[0058] Example 1 S1. Preparation of poly(aromatic ester-ether) diol: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged three times. Then, 4000g of deionized water, 40g of sodium dodecylbenzenesulfonate, 3.0g of sodium iron EDTA, 1000g of 3-allyl-4-hydroxybenzoate, 850g of cyclohexyl-1,4-diethanol monovinyl ether, 5.0g of tert-dodecyl mercaptan, and 0.3g of sodium dithionite were added sequentially to the polymerization reactor. The mixture was stirred at 400rpm and cooled. When the temperature of the polymerization reactor reached 14.0℃, 0.8g of DCP was added to initiate the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 96%, 10g of diethylhydroxylamine was added to the polymerization reactor. The polymerization reaction was terminated by stirring for 10min. The product was then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. Its infrared spectrum is as follows Figure 1 As shown. From Figure 1 It can be seen from this that, at wavenumbers of 1100–1250 cm⁻¹ -1 Characteristic peaks of ether groups appear at [value]; at wavenumbers of 1710–1740 cm⁻¹. -1 An absorption peak for the stretching vibration of aromatic ester groups appears at a wavenumber of 2850–3000 cm⁻¹. -1 The stretching vibration peak of cyclohexyl CH appeared; at wavenumbers of 3200–3300 cm⁻¹ -1 The characteristic peak of hydroxyl groups appeared.

[0059] S2. Preparation of poly(aromatic ester-ether) based biodegradable polyester: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged three times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol and 40g of [unclear text - possibly a chemical compound] were added sequentially to the polymerization reactor. 1,6-Adipic acid, 0.7g triethyl phosphite, and 8.0g trimethylolpropane were mixed and stirred at 200 rpm. The mixture was heated to 195°C, and 1.8g tetrabutyl titanate was added for esterification for 4.5 hours. The water generated during the reaction was then drained through a water separator. The temperature was then raised to 225°C, and 6.0g methyl 2,4-dihydroxybenzoate was added for another 1.5 hours of esterification. The mixture was then subjected to vacuum decompression at 40 Pa for 5.6 hours. The reaction was stopped when the acid value reached 2.6 mg KOH / g. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether)-based biodegradable polyester.

[0060] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0061] Example 2 S1. Preparation of poly(aromatic ester-ether) diol: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged three times. Then, 4300g of deionized water, 45g of sodium dodecylbenzenesulfonate, 3.7g of sodium iron EDTA, 1000g of 3-allyl-4-hydroxybenzoate, 880g of cyclohexyl-1,4-diethanol monovinyl ether, 9.6g of tert-dodecyl mercaptan, and 0.4g of sodium dithionite were added sequentially to the polymerization reactor. The mixture was stirred at 420 rpm and cooled. When the temperature of the polymerization reactor reached 13.0℃, 1.0g of DCP was added to initiate the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 96.5%, 13g of diethylhydroxylamine was added to the polymerization reactor. The polymerization reaction was terminated by stirring for 12 minutes. The product was then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. S2. Preparation of Poly(Aromatic Ester-Ether)-Based Biodegradable Polyester: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged three times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol, 52g of 1,6-adipic acid, 0.9g of triethyl phosphite, and 10.3g of trimethylolpropane were added sequentially to the polymerization reactor. The mixture was stirred at 230rpm, and the temperature was raised. When the temperature of the polymerization reactor reached 198℃, 2.0g of tetrabutyl titanate was added to carry out the esterification reaction for 4.8h. Then, the water generated in the reaction was discharged through a water separator. The temperature was then raised to 228℃, and 7.3g of... After esterification of methyl 2,4-dihydroxybenzoate for 1.8 h, vacuum decompression was carried out, with the negative pressure controlled at 39 Pa. The reaction was continued for 5.9 h, and the reaction was stopped when the acid value reached 2.5 mg KOH / g. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0062] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0063] Example 3 S1. Preparation of poly(aromatic ester-ether) diol: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged four times. Then, 4600g of deionized water, 51g of sodium dodecylbenzenesulfonate, 4.6g of ferrous sulfate, 1000g of 3-allyl-4-hydroxybenzoate, 910g of cyclohexyl-1,4-diethanol monovinyl ether, 13.7g of tert-dodecyl mercaptan, and 0.5g of sodium dithionite were added sequentially to the polymerization reactor. The mixture was stirred at 460 rpm and cooled. When the temperature of the polymerization reactor reached 12.0℃, 1.2g of DCP was added to initiate the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 97.1%, 16g of diethylhydroxylamine was added to the polymerization reactor. The polymerization reaction was terminated by stirring for 16 minutes. The product was then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged four times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol, 65g of 1,6-adipic acid, 1.0g of pentaerythritol diphosphite, and 11.3g of trimethylolpropane were added sequentially to the polymerization reactor. The mixture was stirred at 260rpm, and the temperature was increased. When the temperature of the polymerization reactor reached 203℃, 2.1g of tetrakis(titanate) was added. After esterification of n-butyl ester for 5.0 h, the water generated in the reaction was discharged through a water separator. Then, the temperature was raised to 230℃, and 8.1 g of methyl 2,4-dihydroxybenzoate was added to continue the esterification reaction for 2.1 h. Subsequently, vacuum pressure was applied and the negative pressure was controlled at 37 Pa. The reaction was carried out for 6.2 h. After the acid value reached 2.2 mg KOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0064] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0065] Example 4 S1. Preparation of poly(aromatic ester-ether) diol: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged four times. Then, 4800g of deionized water, 56g of sodium dodecylbenzenesulfonate, 5.3g of ferrous sulfate, 1000g of 3-allyl-4-hydroxybenzoate, 930g of cyclohexyl-1,4-diethanol monovinyl ether, 16.4g of tert-dodecyl mercaptan, and 0.6g of sodium dithionite were added sequentially to the polymerization reactor. The mixture was stirred at 480 rpm and cooled. When the temperature of the polymerization reactor reached 11.0℃, 1.3g of DCP was added to initiate the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 97.3%, 18g of diethylhydroxylamine was added to the polymerization reactor. The polymerization reaction was terminated by stirring for 18 minutes. The product was then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged four times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol, 78g of 1,6-adipic acid, 1.1g of pentaerythritol diphosphite, and 12.8g of trimethylolpropane were added sequentially to the polymerization reactor. The mixture was stirred at 280rpm, and the temperature was increased. When the temperature of the polymerization reactor reached 206℃, 2.2g of tetrakis(titanate) was added. After esterification of n-butyl ester for 5.3 h, the water generated in the reaction was discharged through a water separator. Then, the temperature was raised to 232 °C, and 9.3 g of methyl 2,4-dihydroxybenzoate was added to continue the esterification reaction for 2.4 h. Subsequently, vacuum pressure was applied and the negative pressure was controlled at 36 Pa. The reaction was carried out for 6.5 h. After the acid value reached 2.0 mg KOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0066] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0067] Example 5 S1. Preparation of poly(aromatic ester-ether) diol: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged five times. Then, 5000g of deionized water, 60g of sodium dodecylbenzenesulfonate, 6.0g of dimethyl sulfoxide, 1000g of 3-allyl-4-hydroxybenzoate, 950g of cyclohexyl-1,4-diethanol monovinyl ether, 20.0g of tert-dodecyl mercaptan, and 0.7g of sodium dithionite were added sequentially to the polymerization reactor. The mixture was stirred at 500rpm and cooled. When the temperature of the polymerization reactor reached 10.0℃, 1.5g of DCP was added to initiate the polymerization reaction. When the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 98.0%, 20g of diethylhydroxylamine was added to the polymerization reactor. The polymerization reaction was terminated by stirring for 20min. The product was then discharged, coagulated, and dried to obtain poly(aromatic ester-ether) diol. S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged five times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol, 90g of 1,6-adipic acid, 1.2g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 14.0g of trimethylolpropane were added sequentially. The mixture was stirred at 300rpm, and the temperature was increased until the polymerization reactor temperature reached 210℃. After adding 2.3g of tetrabutyl titanate for esterification reaction for 5.6h, the water generated in the reaction was discharged through a water separator. Then, the temperature was raised to 236℃, and 10.0g of methyl 2,4-dihydroxybenzoate was added for esterification reaction for another 2.6h. Then, vacuum pressure was applied and the negative pressure was controlled at 35Pa. The reaction was carried out for 6.8h. After the acid value was 1.8mgKOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0068] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0069] Comparative Example 1 S1. Preparation of poly(aromatic ester-ether) diol: Other conditions are the same as in Example 1, except that cyclohexyl-1,4-diethanol monovinyl ether is not added during the preparation of poly(aromatic ester-ether) diol. Specifically: First, in a jacketed 10L stainless steel pressure-resistant reactor, nitrogen gas is purged three times. Then, 4000g of deionized water, 40g of sodium dodecylbenzenesulfonate, 3.0g of sodium iron EDTA, 1000g of 3-allyl-4-hydroxybenzoate, 5.0g of tert-dodecyl mercaptan, and 0.3g of sodium dithionite are added sequentially to the polymerization reactor. The mixture is stirred at 400 rpm, cooled, and DCP is added when the temperature of the polymerization reactor reaches 14.0℃. 0.8g was used for polymerization; when the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 96%, 10g of diethylhydroxylamine was added to the polymerization reactor, and the polymerization reaction was terminated by stirring for 10min. The product was discharged, coagulated and dried to obtain poly(aromatic ester-ether) diol-1. S2. Preparation of Poly(Aromatic Ester-Ether)-Based Biodegradable Polyester: Other conditions are the same as in Example 1, except that poly(aromatic ester-ether) diol is not added during the preparation of the poly(aromatic ester-ether)-based biodegradable polyester. Instead, poly(aromatic ester-ether) diol-1 is added in an amount of 1000g. Specifically, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen is purged three times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol-1, 40g of 1,6-adipic acid, 0.7g of triethyl phosphite, and 8.0g of trimethylolpropionic acid are added sequentially to the polymerization reactor. Alkane was stirred at 200 rpm and heated. When the temperature of the polymerization reactor reached 195℃, 1.8 g of tetrabutyl titanate was added for esterification reaction for 4.5 h. Then, the water generated in the reaction was discharged through a water separator. The temperature was then raised to 225℃, and 6.0 g of methyl 2,4-dihydroxybenzoate was added for esterification reaction for another 1.5 h. Then, vacuum pressure was applied and the negative pressure was controlled at 40 Pa. The reaction was carried out for 5.6 h. When the acid value was 2.6 mg KOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0070] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0071] Comparative Example 2 S1. Preparation of poly(aromatic ester-ether) diol: Other conditions are the same as in Example 2, except that 3-allyl-4-hydroxybenzoate is not added during the preparation of poly(aromatic ester-ether) diol. Instead, hydroxyethyl methacrylate is added in an amount of 1000g. Specifically: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen is purged three times. Then, 4300g of deionized water, 45g of sodium dodecylbenzenesulfonate, 3.7g of sodium iron EDTA, 1000g of hydroxyethyl methacrylate, 880g of cyclohexyl-1,4-diethanol monovinyl ether, 9.6g of tert-dodecyl mercaptan, and 0.4g of sodium dithionite are added sequentially to the polymerization reactor. The mixture is stirred at 420rpm and cooled. When the temperature of the polymerization reactor reaches 13.0℃, DCP is added. 1.0g was used for polymerization; when the conversion rate of 3-allyl-4-hydroxybenzoate monomer reached 96.5%, 13g of diethylhydroxylamine was added to the polymerization reactor, and the polymerization reaction was terminated by stirring for 12min. The product was discharged, coagulated and dried to obtain poly(aromatic ester-ether) diol-2. S2. Preparation of Poly(Aromatic Ester-Ether)-Based Biodegradable Polyester: Other conditions are the same as in Example 2, except that poly(aromatic ester-ether) diol is not added during the preparation of the poly(aromatic ester-ether)-based biodegradable polyester. Instead, poly(aromatic ester-ether) diol-2 is added in an amount of 1000g. Specifically, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen is purged three times. Under normal pressure, 1000g of poly(aromatic ester-ether) diol-2, 52g of 1,6-adipic acid, 0.9g of triethyl phosphite, and 10.3g of trimethylolpropionic acid are added sequentially to the polymerization reactor. Alkane was stirred at 230 rpm and heated. When the temperature of the polymerization reactor reached 198℃, 2.0 g of tetrabutyl titanate was added for esterification reaction for 4.8 h. Then, the water generated in the reaction was discharged through a water separator. The temperature was then raised to 228℃, and 7.3 g of methyl 2,4-dihydroxybenzoate was added for esterification reaction for another 1.8 h. Then, vacuum pressure was applied and the negative pressure was controlled at 39 Pa. The reaction was carried out for 5.9 h. After the acid value reached 2.5 mg KOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0072] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0073] Comparative Example 3 S2. Preparation of Poly(Aromatic Ester-Ether) Based Biodegradable Polyester: Other conditions are the same as in Example 3, except that poly(aromatic ester-ether) diol is not added during the preparation of the poly(aromatic ester-ether) based biodegradable polyester. Instead, 1,4-butanediol is added in an amount of 1000g. Specifically, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen is purged four times. Under normal pressure, 1000g of 1,4-butanediol, 65g of 1,6-adipic acid, 1.0g of pentaerythritol diphosphite, and 11.3g of trimethylolpropane are added sequentially. The mixing and stirring speed was 260 rpm. The temperature was increased to 203℃, and 2.1 g of tetrabutyl titanate was added for esterification reaction for 5.0 h. The water generated during the reaction was then discharged through a water separator. The temperature was then increased to 230℃, and 8.1 g of methyl 2,4-dihydroxybenzoate was added for another 2.1 h of esterification reaction. Vacuum pressure was then applied, controlled at 37 Pa, and the reaction was continued for 6.2 h. The reaction was stopped when the acid value reached 2.2 mg KOH / g. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material. Sampling and analysis: Standard samples were prepared, and the tested properties are shown in Table 1.

[0074] Comparative Example 4 S1. Preparation of poly(aromatic ester-ether) diol: Same as in Example 4. S2. Preparation of Poly(Aromatic Ester-Ether) Based Biodegradable Polyester: Other conditions are the same as in Example 4, except that 1,6-adipic acid is not added during the preparation of the poly(aromatic ester-ether) based biodegradable polyester. Instead, acetic acid is added in an amount of 78g. Specifically: First, nitrogen gas is purged four times in a 10L stainless steel pressure-resistant reactor with a jacket. Under normal pressure, 1000g of poly(aromatic ester-ether) diol, 78g of acetic acid, 1.1g of pentaerythritol diphosphite, and 12.8g of trimethylolpropane are added sequentially. The mixture is stirred and mixed at a stirring speed of [missing information]. The temperature was increased to 280 rpm, and when the temperature of the polymerization reactor reached 206℃, 2.2 g of tetrabutyl titanate was added for esterification reaction for 5.3 h. Then, the water generated in the reaction was discharged through a water separator, and the temperature was further increased to 232℃, and 9.3 g of methyl 2,4-dihydroxybenzoate was added for esterification reaction for another 2.4 h. Then, vacuum pressure was applied and the negative pressure was controlled at 36 Pa. The reaction was carried out for 6.5 h, and the acid value was 2.0 mg KOH / g. The reaction was then stopped, and the reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(aromatic ester-ether) based biodegradable polyester material.

[0075] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0076] Comparative Example 5 S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester: Other conditions are the same as in Example 5, except that poly(aromatic ester-ether) diol is not added during the preparation of the poly(aromatic ester-ether)-based biodegradable polyester, but instead poly(carbonate) diol is added. (Ether) diol, the amount added is 1000g, that is: First, in a 10L stainless steel pressure-resistant reactor with a jacket, nitrogen gas was purged five times. Under normal pressure, 1000g of polycarbonate diol, 90g of 1,6-adipic acid, 1.2g of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid], and 14.0g of trimethylolpropane were added sequentially. The mixture was stirred at 300 rpm, and the temperature was increased. When the temperature of the polymerization reactor reached 210℃, 2.3g of tetrabutyl titanate was added. After esterification for 5.6 hours, the water generated during the reaction was discharged through a water separator. Then, the temperature was raised to 236°C, and 10.0 g of methyl 2,4-dihydroxybenzoate was added to continue the esterification reaction for another 2.6 hours. Subsequently, vacuum pressure was applied and the negative pressure was controlled at 35 Pa. The reaction was carried out for 6.8 hours. After the acid value reached 1.8 mg KOH / g, the reaction was stopped. The reaction product was continuously extruded from the bottom of the polymerization reactor, cooled, and pelletized to obtain poly(carbonate-ether) based biodegradable polyester material.

[0077] Sampling and analysis: Standard samples were prepared, and their performance was tested and shown in Table 1.

[0078] Table 1. Properties of Poly(Aromatic Ester-Ether) Based Biodegradable Polyesters

[0079] As shown in Table 1, the number-average molecular weight (Mn) of the material decreased significantly after 45 days of degradation, indicating that the material was effectively degraded and small molecule products were generated. The biodegradation results showed that the degradation rate reached 54%–61% after 30 days, 73%–82% after 90 days, and 93%–98% after 180 days, further verifying the material's excellent degradation performance. Mechanical property results revealed that the tensile strength of the material was above 24.0 MPa, exhibiting excellent mechanical tensile properties. This indicates that the material can be fully utilized in the fields of plastic products such as mulch films and packaging bags.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit it. Those skilled in the art will readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A poly(aromatic ester-ether)-based biodegradable polyester material, characterized in that, The poly(aromatic ester-ether) based biodegradable polyester material was prepared by the following method: Poly(aromatic ester-ether) diols were synthesized by emulsion polymerization using 3-allyl-4-hydroxybenzoate and cyclohexyl-1,4-diethanol monovinyl ether as monomers. The synthesized poly(aromatic ester-ether) diols were then used as raw materials with organic diacids, multifunctional crosslinking agents, stabilizers, and methyl 2,4-dihydroxybenzoate. After esterification and polycondensation reactions, poly(aromatic ester-ether)-based biodegradable polyester materials were prepared.

2. The poly(aromatic ester-ether)-based biodegradable polyester according to claim 1, characterized in that, The 3-allyl-4-hydroxybenzoic acid esters include one or more of the following: methyl 3-allyl-4-hydroxybenzoate, ethyl 3-allyl-4-hydroxybenzoate, propyl 3-allyl-4-hydroxybenzoate, isopropyl 3-allyl-4-hydroxybenzoate, butyl 3-allyl-4-hydroxybenzoate, pentyl 3-allyl-4-hydroxybenzoate, hexyl 3-allyl-4-hydroxybenzoate, and octyl 3-allyl-4-hydroxybenzoate. And / or, the organic dicarboxylic acid is one or more of the C3-C16 straight-chain alkyl dicarboxylic acids.

3. A method for preparing a poly(aromatic ester-ether)-based biodegradable polyester as described in claim 1, characterized in that, Includes the following steps: S1. Preparation of poly(aromatic ester-ether) diols: Add deionized water, emulsifier, activator, 3-allyl-4-hydroxybenzoate, cyclohexyl-1,4-diethanol monovinyl ether, molecular weight regulator, and oxygen scavenger to the reactor, stir and mix, cool down and add initiator to carry out polymerization reaction, and finally add terminator and stir to obtain poly(aromatic ester-ether) diol. S2. Preparation of poly(aromatic ester-ether)-based biodegradable polyester materials: Poly(aromatic ester-ether) diol, organic diacid, stabilizer, and multifunctional crosslinking agent are added to a reaction vessel, mixed and stirred, and then a catalyst is added after heating to carry out the esterification reaction. After heating, methyl 2,4-dihydroxybenzoate is added to continue the esterification reaction. Then, vacuum decompression is carried out to continue the polycondensation reaction. After the reaction stops, poly(aromatic ester-ether) based biodegradable material polyester is obtained.

4. The preparation method according to claim 3, characterized in that, In step S1, the emulsifier includes one or more of alkyl sulfates, alkyl groups, and aryl sulfonates; And / or, the activator includes one or more of the following: sulfadiazine, ferrous sulfate, tetrasodium EDTA, and sodium iron EDTA; And / or, the molecular weight regulator includes one of tert-decyl thiols, tert-dodecyl thiols, tert-tetradecyl thiols, and tert-hexadecyl thiols; And / or, the oxygen scavenger includes one of sodium dithionite, dimethyl ketoxime, isoascorbic acid, carbazide, and N-isopropylhydroxylamine; And / or, the initiator includes one or more of dicumyl peroxide, cumyl hydroperoxide, benzoyl peroxide, and di-tert-butyl peroxide; And / or, the terminating agent includes one or more of NaNO2, hydroxylamine sulfate, diethylhydroxylamine, 2,5-pentanebutylquinone, sodium thiosulfate, and p-aminoazobenzene.

5. The preparation method according to claim 3, characterized in that, The amounts of each component used in step S1 are as follows: And / or, the amount of deionized water used is 400% to 500% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the amount of emulsifier used is 4.0% to 6.0% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the amount of activator used is 0.3% to 0.6% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the mass of cyclohexyl-1,4-diethanol monovinyl ether added is 85% to 95% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the amount of molecular weight regulator used is 0.5% to 2.0% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the amount of oxygen scavenger used is 0.03% to 0.07% of the mass of 3-allyl-4-hydroxybenzoate; And / or, the amount of initiator used is 0.02% to 0.21%, preferably 0.08% to 0.15%; And / or, the amount of the terminator is 1.0% to 2.0% of the mass of 3-allyl-4-hydroxybenzoate.

6. The preparation method according to claim 3, characterized in that, In step S1, cooling means lowering the temperature to 10.0–14.0°C.

7. The preparation method according to claim 3, characterized in that, In step S1 of the polymerization reaction, when the conversion rate of 3-allyl-4-hydroxybenzoate monomer reaches 96% to 98%, a terminator is added; And / or, in step S1, the stirring time after adding the terminator is 10 to 20 minutes.

8. The preparation method according to claim 3, characterized in that, In step S2, the stabilizer is a polar organic compound, including one or more of the following: triethyl phosphite, pentaerythritol diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis(octadecyl)pentaerythritol diphosphite, pentaerythritol tetrakis[β(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and N,N'-bis(3(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine; And / or, in step S2, the multifunctional crosslinking agent is a crosslinking agent having three or more functional groups; the functional groups include one or more of carboxylic acid groups, acid anhydride groups, and hydroxyl groups; And / or, in step S2, the catalyst includes one of tetrabutyl titanate, tetraisopropyl titanate, diethylzinc, zinc octanoate, zinc acetate, zinc oxide, and zinc chloride.

9. The preparation method according to claim 3, characterized in that, The amounts of each component used in step S2 are as follows: The amount of organic dicarboxylic acid used is 4.0% to 9.0% of the mass of the poly(aromatic ester-ether) diol; And / or, the amount of stabilizer used is 0.07% to 0.12% of the mass of the poly(aromatic ester-ether) diol; And / or, the amount of the multifunctional crosslinking agent used is 0.5% to 2.6% of the mass of the poly(aromatic ester-ether) diol; And / or, the amount of catalyst used is 0.15% to 0.35% of the mass of the poly(aromatic ester-ether) diol; And / or, the amount of methyl 2,4-dihydroxybenzoate used is 0.6% to 1.0% of the mass of the poly(aromatic ester-ether) diol.

10. The preparation method according to claim 3, characterized in that, In step S2, the temperature is increased to 195–210°C; And / or, in step S2, the esterification reaction takes 4.5 to 5.6 hours; And / or, in step S2, after the esterification reaction, the water generated in the reaction is discharged through a water separator, and then the temperature is raised to continue the esterification reaction; And / or, in step S2, the temperature is further increased to 225-236°C; And / or, in step S2, the esterification reaction continues for 1.5 to 2.6 hours; And / or, in step S2, vacuuming and depressurization involves controlling the negative pressure at 35–40 Pa; And / or, in step S2, the time for the polycondensation reaction to continue after vacuum decompression is 5.6 to 6.8 hours; And / or, in step S2, the reaction continues until the acid value reaches 1.8–2.7 mg KOH / g, at which point the reaction is stopped.

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