Biodegradable polyester material as well as preparation method and application thereof

Abstract

The invention relates to a biodegradable polyester material as well as a preparation method and application thereof. The biodegradable polyester material is prepared from the following components in parts by weight: 74 to 98 parts of aliphatic-aromatic copolymerized polyester, 1 to 8 parts of polylactic acid, 0.3 to 1.1 parts of antioxidant and 0.3 to 1.1 parts of hydrolysis-resistant agent. The antioxidant and the hydrolysis-resistant agent are added, the peak molecular weight and the T content of the aliphatic-aromatic copolyester are regulated and controlled, and the D content of the polylactic acid is regulated and controlled, so that the obtained biodegradable polyester material has low odor during heating or after heating.

Description

Technical Field

[0001] The present invention relates to the technical field of degradable materials, and more specifically, to a biodegradable polyester material, a preparation method thereof, and an application thereof. Background Art

[0002] Compared with PE film bags, biodegradable film bags still have deficiencies in terms of odor. After being heated at high temperature, they smell burnt, which limits the popularization and application of biodegradable film bags in the food packaging field.

[0003] Currently, there are mainly two ways to solve the odor problem of biodegradable film bags: one is to add adsorbents for odor adsorption, such as patent CN115895210A, but the effect of reducing odor by this method is not obvious, and this physical adsorption process is affected by temperature, and the improvement effect on the odor generated by high-temperature heating is not good; the other is to add flavors for odor masking, such as patent CN113999500A, but the masking effect of this method is unstable. More importantly, the addition of flavors will affect the odor of the food itself and is not easily accepted by consumers. The above two ways both have deficiencies and do not fundamentally solve the odor problem. Therefore, a solution for low-odor biodegradable film bags is urgently needed. Summary of the Invention

[0004] The primary object of the present invention is to overcome the problem of strong odor of biodegradable materials in the current technology and provide a biodegradable polyester material.

[0005] A further object of the present invention is to provide a preparation method of the above-mentioned biodegradable polyester material.

[0006] A further object of the present invention is to provide an application of the above-mentioned biodegradable polyester material in the preparation of degradable films or degradable bags.

[0007] The above objects of the present invention are achieved by the following technical solutions:

[0008] A biodegradable polyester material, comprising the following components in parts by weight:

[0009] Aliphatic-aromatic copolyester 74-98 parts,

[0010] Polylactic acid 1-8 parts,

[0011] Antioxidant 0.3-1.1 parts,

[0012] Hydrolysis-resistant agent 0.3-1.1 parts;

[0013] The peak molecular weight of the aliphatic-aromatic copolyester ≥80000, and the T content is 45-56 mol%;

[0014] The polylactic acid is a copolymer of L-lactic acid and D-lactic acid, and the proportion of D-lactic acid repeating units is 3-25 mol%.

[0015] It should be understood that the T content in the present invention refers to the ratio of the repeating units from aromatic diacids in the aliphatic-aromatic copolyester to the sum of the repeating units from aromatic diacids and aliphatic diacids.

[0016] In the present invention, the aliphatic-aromatic copolyester serves as the main resin, and the addition of polylactic acid is beneficial to improving the film-forming performance of the biodegradable polyester material. However, the amount of polylactic acid cannot be too much because the plasticizing performance of polylactic acid is usually worse than that of the aliphatic-aromatic copolyester during the processing, resulting in polylactic acid being more easily sheared and cut, generating more small-molecule substances and causing a strong odor of the biodegradable polyester material.

[0017] The addition of antioxidants can reduce the oxidative degradation of the aliphatic-aromatic copolyester and polylactic acid by free radicals during processing, and the hydrolysis-resistant agent also has the effect of preventing the degradation of the aliphatic-aromatic copolyester and polylactic acid. Thus, both can reduce the odor of the biodegradable polyester material.

[0018] The peak molecular weight refers to the molecular weight of the highest peak in the molecular weight distribution curve of the polymer, which can well reflect the molecular weight and the main distribution range of the polymer. In the present invention, it is also necessary to further regulate the peak molecular weight and T content of the aliphatic-aromatic copolyester and the D content of the polylactic acid to significantly reduce the odor of the biodegradable polyester material. If the peak molecular weight of the aliphatic-aromatic copolyester is too low, the aliphatic-aromatic copolyester is easily degraded into small-molecule substances, resulting in a strong odor of the biodegradable polyester material. If the T content of the aliphatic-aromatic copolyester is too low, it is also prone to decomposition, leading to a strong odor of the biodegradable polyester material; the T content of the aliphatic-aromatic copolyester cannot be too high either, otherwise the flexibility of its molecular chain decreases, and it is more easily sheared and cut during processing, thus becoming short molecular chains and causing the odor of the biodegradable polyester material to increase. The D content of the polylactic acid cannot be too low or too high, otherwise, due to the large difference in the crystallinity between the polylactic acid and the aliphatic-aromatic copolyester, the compatibility between the two is poor, the degree of entanglement between molecules decreases, and the biodegradable polyester material is easily degraded when heated, resulting in an increase in odor.

[0019] In the present invention, the dosage of the aliphatic-aromatic copolyester may specifically be 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97 or 98 parts by weight. The dosage of polylactic acid may specifically be 1, 2, 3, 4, 5, 6, 7 or 8 parts. The dosage of the antioxidant may specifically be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or 1.1 parts by weight. The dosage of the anti-hydrolytic agent may specifically be 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0 or 1.1 parts by weight.

[0020] In the present invention, the T content of the aliphatic-aromatic copolyester may specifically be 45 mol%, 46 mol%, 47 mol%, 48 mol%, 49 mol%, 50 mol%, 51 mol%, 52 mol%, 53 mol%, 54 mol%, 55 mol% or 56 mol%.

[0021] Preferably, the T content of the aliphatic-aromatic copolyester is 48 - 53 mol%. In this range, the resulting biodegradable polyester material has a lower odor.

[0022] In the present invention, the T content of the aliphatic-aromatic copolyester can be measured by nuclear magnetic resonance. The specific process is as follows: Take 20 mg of the aliphatic-aromatic copolyester sample and dissolve it in 0.6 mL of deuterated chloroform, and then use a Bruker AV 500 nuclear magnetic resonance spectrometer to measure 1HNMR at room temperature, calibrating the chloroform solvent peak near 7.26 ppm. Among them, the 4 hydrogen atoms on the benzene ring in the repeating unit of the aromatic dicarboxylic acid appear near 8.10 ppm; the 4 hydrogen atoms of the two CH 2 units adjacent to the carbonyl in the repeating unit of the aliphatic dicarboxylic acid appear near 2.33 ppm. Therefore, the molar contents of the aromatic dicarboxylic acid and aliphatic dicarboxylic acid components can be represented by the integral areas (IT and IA) of the peaks at 8.10 ppm and 2.33 ppm:

[0023] The molar content (T content) of the aromatic dicarboxylic acid in the aliphatic-aromatic copolyester = IT / (IT + IA) × 100%.

[0024] In the present invention, the peak molecular weight of the aliphatic-aromatic copolyester may specifically be: 80000, 82000, 85000, 87000, 90000, 95000, 100000, 105000, 110000, 115000, 120000, 125000, 130000, 135000, 140000, 145000, 150000, 155000 or 160000.

[0025] Preferably, the peak molecular weight of the aliphatic-aromatic copolyester is 85,000 to 120,000. In this range, the resulting biodegradable polyester material has a lower odor.

[0026] In the present invention, the peak molecular weight of the aliphatic-aromatic copolyester can be measured by gel permeation chromatography. The test process of gel permeation chromatography can be as follows: GPC is tested using the ACQUITY APC TM equipment of Waters company, the test temperature is 40 °C, XT45, XT200 and XT459 chromatographic columns are used, the solvent: tetrahydrofuran, the mobile phase flow rate: 0.5 mL / min. Polystyrene standards are used as the standard samples, and the results are the average of three times.

[0027] In the present invention, the content of D-lactic acid in polylactic acid can specifically be: 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%.

[0028] Preferably, the content of D-lactic acid in the polylactic acid is 10 to 17%. In this range, the resulting biodegradable polyester material has a lower odor.

[0029] In the present invention, the content of D-lactic acid in polylactic acid can be measured by gas chromatography. The specific process is as follows: Place 100 mg of the polylactic acid sample in a hydrothermal reactor, add 10 ml of methanol, add 1 drop of NaOH aqueous solution, and seal the hydrothermal reactor. Place the hydrothermal reactor in a forced-air oven at 150 °C. After 60 min, take out the hydrothermal reactor and cool it to room temperature with running water. Transfer the filtered sample solution to a gas chromatograph (Agilent 8860 gas chromatograph, CP7502 chromatographic column), determine the peaks corresponding to methyl D-lactate and methyl L-lactate according to the retention time, and record the peak areas of methyl D-lactate and methyl L-lactate. Divide the peak area of methyl D-lactate by the sum of the peak areas of methyl D-lactate and methyl L-lactate to obtain the content of D-lactic acid (D-type lactic acid) in the polylactic acid.

[0030] In the present invention, the aliphatic-aromatic copolyester is used as the main resin, and its content accounts for more than 60 wt% of the biodegradable polyester material.

[0031] In the present invention, the aliphatic-aromatic copolyester refers to a copolymer of an aliphatic dicarboxylic acid and / or its ester-forming derivative, an aromatic dicarboxylic acid and / or its ester-forming derivative and a diol.

[0032] In the present invention, the aliphatic-aromatic copolyester can be either commercially available or prepared by oneself. The method for self-preparation can be as follows: an aliphatic dicarboxylic acid and / or its ester-forming derivative, an aromatic dicarboxylic acid and / or its ester-forming derivative, and a diol are mixed and first reacted at 180 to 200 °C for 2 to 4 hours. Then a catalyst is added, and the reaction is continued at 230 to 260 °C and 180 to 250 Pa for 6 to 10 hours to obtain the aliphatic-aromatic copolyester.

[0033] More preferably, the molar ratio of the sum of the molar amounts of the aliphatic dicarboxylic acid and / or its ester-forming derivative and the aromatic dicarboxylic acid and / or its ester-forming derivative to the molar amount of the diol is 1:(1.05 to 1.3).

[0034] More preferably, the diol is at least one of butanediol and propanediol.

[0035] More preferably, a branching agent is added during the mixing process, and the branching agent includes but is not limited to glycerol.

[0036] Even more preferably, the mass ratio of the dicarboxylic acid to the branching agent is 1:(0.0003 to 0.0006).

[0037] More preferably, the catalyst includes but is not limited to tetrabutyl titanate.

[0038] More preferably, the aliphatic dicarboxylic acid is at least one of the C 4～12 dicarboxylic acids.

[0039] Specifically, the C 4～12 dicarboxylic acid is at least one of succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, and dodecanedioic acid.

[0040] More preferably, the aromatic dicarboxylic acid is terephthalic acid.

[0041] Specifically, the biodegradable polyester can be at least one of poly(butylene adipate terephthalate) (PBAT) and poly(butylene sebacate terephthalate) (PBSeT).

[0042] In the present invention, polylactic acid can be either commercially available or prepared by oneself. The method for self-preparation can be as follows: ring-opening polymerization of lactide is carried out to obtain the polylactic acid.

[0043] Preferably, the lactide includes L-lactide and meso-lactide.

[0044] More preferably, the mass ratio of L-lactide to meso-lactide is 95 to 60:5 to 40.

[0045] More preferably, the ring-opening polymerization reaction is carried out in the presence of a catalyst, and the catalyst includes but is not limited to stannous octoate.

[0046] More preferably, the process of the ring-opening polymerization reaction is as follows: first react at 130-145 °C and 1000-1400 Pa for 3-5 hours, and then react at 160-180 °C and 300-500 Pa for 4-8 hours.

[0047] In the present invention, the content of D-lactic acid in polylactic acid can be measured by gas chromatography.

[0048] Preferably, the peak molecular weight of the polylactic acid is 90,000-220,000.

[0049] The peak molecular weight of the polylactic acid of the present invention can be measured by gel permeation chromatography. The test process of gel permeation chromatography can be as follows: GPC uses the ACQUITY APC TM equipment of Waters company for testing, the test temperature is 40 °C, using XT45, XT200 and XT459 chromatographic columns, solvent: tetrahydrofuran, mobile phase flow rate: 0.5 mL / min. Using polystyrene standard as the standard sample, and the result is the average value of three times.

[0050] Preferably, the antioxidant includes but is not limited to at least one of hindered phenol antioxidants, phosphite antioxidants, or amine antioxidants.

[0051] Preferably, the biodegradable polyester material further includes 0.1-1 part of a lubricant.

[0052] More preferably, the lubricant is at least one of ethylene bisstearamide, monoglyceride, oleic acid amide or erucic acid amide.

[0053] Preferably, the hydrolysis-resistant agent includes but is not limited to at least one of polymeric carbodiimide, methyl bisphenyl carbodiimide or dicyclohexyl carbodiimide.

[0054] In the present invention, a certain amount of inorganic filler can also be added to reduce the production cost of the biodegradable polyester material.

[0055] Preferably, the biodegradable polyester material further includes 0-10 parts of inorganic filler, and more preferably 3-10 parts of inorganic filler.

[0056] More preferably, the inorganic filler is at least one of talc powder or calcium carbonate.

[0057] Further preferably, the inorganic filler is talc powder.

[0058] In the case of adding inorganic fillers, choosing talcum powder can make the biodegradable polyester material have a smaller odor.

[0059] More preferably, the particle size D50 of the inorganic filler is ≤ 13 μm.

[0060] Further preferably, the particle size D50 of the inorganic filler is 3 - 12 μm.

[0061] Further preferably, the particle size D50 of the inorganic filler is 4 - 8 μm.

[0062] In the case of adding inorganic fillers, choosing inorganic fillers within this particle size range can reduce the damage of rigid inorganic fillers to aliphatic-aromatic copolyester during the processing, avoid more aliphatic-aromatic copolyester molecular chains from being cut off, and thus further reduce the odor of the biodegradable polyester material.

[0063] In the present invention, the test method for the particle size D50 of the inorganic filler can be determined with reference to the method of GB / T 19077.1-2008 "Particle Size Analysis - Laser Diffraction Method".

[0064] Preferably, the biodegradable polyester material further comprises 0.1 - 2 parts of other additives.

[0065] More preferably, the other additives are at least one of an antistatic agent, a UV stabilizer or a UV absorber.

[0066] Optionally, the antistatic agent is at least one of ethoxylated alkyl acid amide, glycerol monostearate or ethoxylated alkylamine.

[0067] Optionally, the UV stabilizer is at least one of 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-(2,4-dimethylphenyl)-2H-benzotriazol-4-one or bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0068] Optionally, the UV absorber is at least one of 2-hydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, phenyl salicylate or 2-hydroxy-4-n-octyloxybenzophenone.

[0069] The preparation method of the above-mentioned biodegradable polyester material comprises the following steps: mixing each component, melt-extruding, and pelletizing to obtain the biodegradable polyester material.

[0070] Preferably, the temperature of the melt-extrusion is 160 - 180 °C; the length-diameter ratio of the screw of the melt-extrusion extruder is 30 - 50:1, and the screw speed is 250 - 400 rpm.

[0071] The application of the above biodegradable polyester material in the preparation of degradable films or degradable bags is also within the scope of protection of the present invention.

[0072] A degradable film or a degradable bag is prepared from the above biodegradable polyester material.

[0073] A degradable film or a degradable bag, wherein the degradable film is a food packaging film and the degradable bag is a food packaging bag.

[0074] Preferably, the food packaging film is a heatable food packaging film, and the food packaging bag is a heatable food packaging bag; the heating temperature is not more than 90 °C.

[0075] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0076] By adding antioxidants, hydrolysis-resistant agents, and regulating the peak molecular weight and T content of the aliphatic-aromatic copolyester, as well as regulating the D content of polylactic acid, the obtained biodegradable polyester material has a low odor when heated or after heating. Specific Embodiments

[0077] In order to more clearly and completely describe the technical solutions of the present invention, the present invention will be further described in detail below through specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Various changes can be made within the scope defined by the rights of the present invention.

[0078] Some of the reagents selected in the embodiments and comparative examples of the present invention are described as follows:

[0079] I. Aliphatic-aromatic copolyester

[0080] PBAT1#: Self-made, and its preparation method is as follows:

[0081] 3.0 kg of terephthalic acid, 2.8 kg of adipic acid, 3.7 kg (in excess) of 1,4-butanediol, and 2.8 g of glycerol are all added to the reaction kettle, and the temperature is 190 °C (temperature T 1 ) and stirred for 3 hours (time t 1 ), then 0.01% of tetrabutyl titanate based on the total mass of the dibasic acid and the diol is added as a catalyst, and the temperature is raised to 250 °C (temperature T 2 ), the vacuum is turned on, the vacuum degree is 200 Pa, and the reaction is carried out for 8 hours (time t 2 ), thus obtaining PBAT1#. The peak molecular weight of PBAT1# is 118362, and the terephthalic acid content is 48.5%.

[0082] PBAT2#: Self-made. The difference in its preparation method from PBAT1# lies in that terephthalic acid is 2.7 kg. The peak molecular weight of PBAT2# is 119731, and the terephthalic acid content is 45.1%.

[0083] PBAT3#: Self-made. The difference in its preparation method from PBAT1# lies in that terephthalic acid is 3.5 kg and 1,4-butanediol is 3.7 kg. The peak molecular weight of PBAT3# is 116396, and the terephthalic acid content is 52.2%.

[0084] PBAT4#: Self-made. The difference in its preparation method from PBAT1# lies in that terephthalic acid is 4.0 kg and 1,4-butanediol is 4.3 kg. The peak molecular weight of PBAT4# is 121368, and the terephthalic acid content is 55.1%.

[0085] PBAT5#: Self-made. The difference in its preparation method from PBAT1# lies in that time t 1 is 2 hours, and time t 2 is 6 hours. The peak molecular weight of PBAT5# is 85682, and the terephthalic acid content is 48.2%.

[0086] PBAT6#: Self-made. The difference in its preparation method from PBAT1# lies in that time t 1 is 4 hours, and time t 2 is 10 hours. The peak molecular weight of PBAT6# is 153221, and the terephthalic acid content is 48.4%.

[0087] PBAT7#: Self-made. The difference in its preparation method from PBAT1# lies in that terephthalic acid is 2.3 kg. The peak molecular weight of PBAT7# is 113321, and the terephthalic acid content is 41.6%.

[0088] PBAT8#: Self-made. The difference in its preparation method from PBAT1# lies in that time t 1 is 2 hours, and time t 2 is 4 hours. The peak molecular weight of PBAT8# is 69576, and the terephthalic acid content is 48.3%.

[0089] II. Polylactic acid

[0090] PLA1#: Self-made. Its preparation method is as follows: The PLLA / PDLA copolymer is self-made. Use 80 parts by weight of L-lactide (L content ≥ 99.5%, the same below), 20 parts by weight of meso-lactide (D content is about 50%, the same below). Dissolve the lactide in hexanediol, add stannous octoate (0.1 wt% of the total amount of lactide used), and carry out ring-opening polymerization. First, react at a reaction temperature of 138 °C and a reaction pressure of 1200 Pa for 4 hours (time t 3 ), and then react at a reaction temperature of 170 °C and a reaction pressure of 400 Pa for 6 hours (time t 4 ). Granulate underwater, crystallize, and dry to obtain PLA1#. The content of dextrorotatory lactic acid in PLA1# is 10.2%, and the peak molecular weight is 167379.

[0091] PLA2#: Self-made. The difference in its preparation method from PLA1# is that: the amount of L-lactide used is 94 parts by weight, and the amount of meso-lactide used is 6 parts by weight. The content of dextrorotatory lactic acid in PLA2# is 3.3%, and the peak molecular weight is 163398.

[0092] PLA3#: Self-made. The difference in its preparation method from PLA1# is that: the amount of L-lactide used is 68 parts by weight, and the amount of meso-lactide used is 32 parts by weight. The content of dextrorotatory lactic acid in PLA3# is 16.1%, and the peak molecular weight is 164852.

[0093] PLA4#: Self-made. The difference in its preparation method from PLA1# is that: the amount of L-lactide used is 50 parts by weight, and the amount of meso-lactide used is 50 parts by weight. The content of dextrorotatory lactic acid in PLA4# is 24.9%, and the peak molecular weight is 163950.

[0094] PLA5#: Self-made. The difference in its preparation method from PLA1# is that: time t3 is 3 hours, and time t4 is 4 hours. The content of dextrorotatory lactic acid in PLA5# is 10.3%, and the peak molecular weight is 124171.

[0095] PLA6#: Self-made. The difference in its preparation method from PLA1# is that: time t3 is 5 hours, and time t4 is 8 hours. The content of dextrorotatory lactic acid in PLA6# is 10.4%, and the peak molecular weight is 208356.

[0096] PLA7#: Self-made. The difference in its preparation method from PLA1# is that: the amount of L-lactide used is 98 parts by weight, and the amount of meso-lactide used is 2 parts by weight. The content of dextrorotatory lactic acid in PLA7# is 1.1%, and the peak molecular weight is 165295.

[0097] Inorganic filler 1#: Talc powder, Haiyang, HY-TA05, D50 is 4.0μm;

[0098] Inorganic filler 2#: Talc powder, Haiyang, HY-TA08, D50 is 7.7μm;

[0099] Inorganic filler 3#: Talc powder, Haiyang, HY-TA10, D50 is 11.2μm;

[0100] Inorganic filler 4#: Calcium carbonate, Omya, 5-JI, D50 is 5.0μm;

[0101] Lubricant 1#: Monoglyceride, commercially available;

[0102] Antioxidant 1#: Antioxidant, Antioxidant 168, commercially available;

[0103] Hydrolysis-resistant agent 1#: Polymeric carbodiimide, Langyi, HYMAX 210;

[0104] Other additive 1#: UV absorber, UV-326, commercially available.

[0105] Unless otherwise specified, each component (such as other additive 1#) selected in each parallel example and comparative example is the same commercially available product.

[0106] For the biodegradable polyester materials provided in each example and comparative example of the present invention, the performance is determined according to the following test methods:

[0107] (1) Total volatile organic compounds (TVOC) content: Referring to the Volkswagen PV 3341-1996 standard, the TVOC of the material is tested using a headspace-gas chromatography-flame ionization detector combined instrument, and the test conditions are 80°C, constant temperature for 5h.

[0108] (2) Odor level test: Referring to Volkswagen PV 3900-2000, take 20g of pellets and place them in a 1L odor bottle, seal it well with aluminum foil, heat it in an oven at 80±2°C for 2h, take it out and cool it to 60±5°C, then open the odor bottle cap, and 10 people quickly complete the odor test and rating. The rating refers to Table 2. The result is the average value of 10 people. The lower the average value, the lower the odor.

[0109] Level Evaluation description Level 1 The smell cannot be felt Level 2 There is a smell, but it is not an interfering smell Level 3 There is an obvious smell, but it is not an interfering smell Level 4 There is an interfering smell Level 5 There is a strong interfering smell Level 6 There is an intolerable smell

[0110] The biodegradable polyester materials of the embodiments and comparative examples of the present invention are prepared by the following preparation method: Weigh each component according to the formula, mix each component evenly, then put them into a twin-screw extruder, melt extrude and granulate to obtain the biodegradable polyester material. Among them, the temperatures of the twin-screw extruder from zone 1 to zone 10 are 160 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 170 °C, 175 °C, 175 °C and 175 °C in sequence, the screw length-diameter ratio is 40:1, and the screw rotation speed is 300 rpm.

[0111] Examples 1 to 17

[0112] Examples 1 to 17 provide a series of biodegradable polyester materials, and their formulas are shown in Table 1 and Table 2.

[0113] Table 1 Formulas of Examples 1 to 9 (parts by weight)

[0114] 。

[0116] Table 2 Formulas of Examples 10 to 17 (parts by weight)

[0117]

[0118] 。

[0120] Comparative Examples 1 to 6

[0121] Comparative Examples 1 to 6 provide a series of biodegradable polyester materials, and their formulas are shown in Table 3.

[0122] Table 3 Formulas of Comparative Examples 1 to 6 (parts by weight)

[0123] 。

[0125] Measure the properties of the biodegradable polyester materials of each example and comparative example according to the above-mentioned test methods, and the test results are shown in Table 4.

[0126] Table 4 Test Results of the Properties of the Biodegradable Polyester Materials of Each Example and Comparative Example

[0127] 。

[0130] As can be seen from Table 4:

[0131] The TVOC of the biodegradable polyester materials of Examples 1 to 17 are all at 7.6 μgC·g -1 and below, and the odor grade tests are all at 4.2 and below, indicating that the biodegradable polyester materials of the present invention have low odor.

[0132] In Comparative Example 1, the T content of the aliphatic-aromatic copolyester added was too low; in Comparative Example 2, the peak molecular weight of the aliphatic-aromatic copolyester added was too low; in Comparative Example 3, the D content of the additive was too low; in Comparative Example 4, too much polylactic acid was added; in Comparative Example 5, no antioxidant was added; and in Comparative Example 6, no hydrolysis-resistant agent was added. As a result, the biodegradable polyester materials obtained all had a high odor.

[0133] Obviously, the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A biodegradable polyester material, characterized in that: The composition comprises the following components in parts by weight: Aliphatic-aromatic copolyester 74-98 parts, 1 to 8 parts of polylactic acid, 0.3-1.1 parts of antioxidant, 0.3-1.1 parts of hydrolysis resistance agent; The peak molecular weight of the aliphatic-aromatic copolyester is ≥80,000 and the T content is 45 to 56 mol%; The polylactic acid is a copolymer of L-lactic acid and D-lactic acid, and the D-lactic acid repeating unit accounts for 3 to 25 mol%.

2. The biodegradable polyester material according to claim 1, characterized in that: The peak molecular weight of the polylactic acid is 90,000 to 220,000.

3. The biodegradable polyester material according to claim 1, characterized in that: The antioxidant is at least one of a hindered phenol antioxidant, a phosphite antioxidant or an amine antioxidant.

4. The biodegradable polyester material according to claim 1, characterized in that: The anti-hydrolysis agent is at least one of polymeric carbodiimide, methyl diphenyl carbodiimide or dicyclohexyl carbodiimide.

5. The biodegradable polyester material according to claim 1, characterized in that: The biodegradable polyester material also includes 0.1 to 1 parts of a lubricant.

6. The biodegradable polyester material according to claim 1, characterized in that: The biodegradable polyester material also includes 0 to 10 parts of inorganic filler.

7. The biodegradable polyester material according to claim 1, characterized in that: The aliphatic-aromatic copolyester is a copolymer of an aliphatic dibasic acid and / or its ester-forming derivative, an aromatic dibasic acid and / or its ester-forming derivative and a diol. The aliphatic dibasic acid is C 4～12 The aromatic dibasic acid is terephthalic acid, and the diol is at least one of butanediol and propylene glycol.

8. The method for preparing the biodegradable polyester material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the components, melt-extruding and granulating to obtain the biodegradable polyester material.

9. Use of the biodegradable polyester material according to any one of claims 1 to 7 in the preparation of a degradable film or a degradable bag.

10. A degradable film or degradable bag, characterized in that: It is made from the biodegradable polyester material according to any one of claims 1 to 7.

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