A biodegradable material and a preparation method and application thereof

Abstract

The application relates to a biodegradable material and a preparation method and application thereof. The biodegradable material comprises the following components in parts by weight: 85-92 parts of biodegradable polyester, 3-8 parts of polylactic acid and 0-8 parts of inorganic filler. The biodegradable polyester with certain number-average molecular weight and the polylactic acid with certain number-average molecular weight and D-lactic acid unit content are matched, so that the initial edge sealing strength and long-acting edge sealing strength of the biodegradable material after being made into a film are obviously improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer material modification, and more particularly to a biodegradable material and a preparation method and application thereof. BACKGROUND

[0002] Compared with traditional PE, the edge sealing strength of biodegradable material is weak, especially the long-term edge sealing: the edge sealing strength of biodegradable film decreases rapidly after being placed for one week or more, which limits its application in the fields of logistics express bags, clothing bags, catering bags and food bags, etc. At present, there is a strong demand for good initial edge sealing and good long-term edge sealing in the market: on the one hand, with the development of the industry, lightweight thinning is the future trend of biodegradable film production, and under the trend of thinning, the edge sealing strength of biodegradable film is more challenged; on the other hand, the film products on the market are generally first made into films, and then cut and sealed into products, which has a 10-day turnaround time, and at the same time, some products are processed into films in China, and then transported to foreign terminals to be processed into products, which has a turnaround time of up to 3 months.

[0003] At present, there are two ways to solve the problem of long-term edge sealing in the industry: one is to make the film thicker, which not only affects the use of the product, but also increases the cost; the other is to improve the process, such as upgrading the cutter and increasing the temperature, which has limited effect on the improvement of edge sealing strength.

[0004] The Chinese patent entitled "A biodegradable material, a preparation method and application thereof" provides a biodegradable material with good edge sealing strength, but it does not focus on the long-term edge sealing strength of the material.

[0005] Therefore, it is urgent to develop a biodegradable material with good long-term edge sealing strength to meet market demand. SUMMARY

[0006] The primary object of the present application is to overcome the problem of poor edge sealing strength of biodegradable film in the prior art, especially the poor long-term edge sealing strength, and to provide a biodegradable material.

[0007] A further object of the present application is to provide a preparation method of the biodegradable material.

[0008] A further object of the present application is to provide an application of the biodegradable material in the preparation of a film.

[0009] A further object of the present application is to provide a biodegradable film.

[0010] The above objects of the present application are achieved by the following technical solutions:

[0011] A biodegradable material, comprising the following components in parts by weight:

[0012] biodegradable polyester 85-92 parts,

[0013] polylactic acid 3-8 parts,

[0014] inorganic filler 0-8 parts;

[0015] The biodegradable polyester is a copolymer of diacid and / or its ester-forming derivative and dihydric alcohol, and the number average molecular weight of the biodegradable polyester is 50000-100000.

[0016] The number average molecular weight of the polylactic acid is 60000-160000, and the content of D-lactic acid unit in the polylactic acid is 8-51 mol%.

[0017] In the present application, the polylactic acid is added to improve the film-forming performance of the biodegradable material.

[0018] The inventors of the present application found through research that by controlling the number average molecular weight of the biodegradable polyester within a certain range, the biodegradable polyester molecules can quickly diffuse and entangle at a momentary high temperature when the biodegradable material film is edge sealed, thereby improving the edge sealing strength and long-term edge sealing strength. If the number average molecular weight of the biodegradable polyester is too small, although the molecules can still quickly diffuse and entangle during edge sealing, the bulk strength of the material decreases significantly, thereby resulting in an inability to improve the edge sealing strength; if the number average molecular weight of the biodegradable polyester is too large, the molecules are difficult to quickly diffuse and entangle, resulting in an inability to improve the edge sealing strength.

[0019] In addition, the number average molecular weight of the polylactic acid and the content of D-lactic acid unit also need to be controlled within a certain range, thereby improving the compatibility of the polylactic acid and the biodegradable polyester, and further ensuring the edge sealing strength and long-term edge sealing strength of the biodegradable material.

[0020] In the present application, the inorganic filler can be added or not added, and when the inorganic filler is not added, the edge sealing strength and long-term edge sealing strength of the biodegradable material are better; when the inorganic filler is added, the amount of the inorganic filler added cannot be too much, in order to ensure the edge sealing strength and long-term edge sealing strength of the biodegradable material.

[0021] In the present application, the testing method of the number average molecular weight and the molecular weight distribution coefficient of the biodegradable polyester is: GPC uses the ACQUITY APC TM device to test, the test temperature is 40℃, XT45, XT200 and XT459 chromatographic columns are used, the solvent is tetrahydrofuran, the flow rate of the mobile phase is 0.5mL / min. Polystyrene standards are used as standards, and the results are the average of three times.

[0022] In the present application, the testing method of the number average molecular weight and the molecular weight distribution coefficient of polylactic acid is as follows: GPC uses ACQUITY APC TM The device is tested at a test temperature of 40 DEG C, using XT45, XT200 and XT459 chromatographic columns, solvent: tetrahydrofuran, flow rate of mobile phase: 0.5 mL / min. Polystyrene standards are used as markers, and the results are averaged three times.

[0023] In the present application, the content of D-lactic acid units of polylactic acid can be detected according to the following steps: (1) 100 ± 10 mg of ground and crushed polylactic acid sample is weighed and placed in a 25 mL pressure container inner tank; (2) 10 mL of methanol and 1 drop of dilute sulfuric acid are added; (3) the pressure container is sealed and placed in a 150 DEG C thermostat for 4 hours; (4) the pressure container is removed and cooled to room temperature before opening; (5) the sample solution is filtered through a membrane filter (pore size 0.22 or 0.45 μm) and transferred to a gas chromatography special sample vial, and the operation is performed according to the manufacturer's instructions; (6) the content of D-lactic acid units is calculated according to the peak area ratio.

[0024] In the present application, the content of biodegradable polyester as the main resin is more than 70 wt% of the polyester composition.

[0025] In the present application, the number average molecular weight of biodegradable polyester can be 50000, 60000, 70000, 80000, 90000 or 100000.

[0026] The biodegradable polyester copolymerized by the commonly used diacid and / or its ester-forming derivative and the commonly used diol can be used in the present application.

[0027] In the present application, the biodegradable polyester can be commercially available or self-made.

[0028] In the present application, the process of self-made biodegradable polyester can be as follows:

[0029] The diol, diacid and branching agent are mixed and reacted at 190-220 DEG C for 2-6 hours, a catalyst is added, and then reacted at 240-260 DEG C for 4-16 hours to obtain the biodegradable polyester.

[0030] In the present application, the molar ratio of the diol and diacid is (1.1-2.4): 1.

[0031] Preferably, the mass ratio of the diacid and branching agent is 2.6:(0.001-0.003).

[0032] Preferably, the catalyst includes but is not limited to tetrabutyl titanate.

[0033] Preferably, the branching agent includes, but is not limited to, glycerol and / or trimethylolpropane.

[0034] Preferably, the diacid is an aliphatic diacid and / or an aromatic diacid.

[0035] More preferably, the aliphatic diacid is at least one of succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid or dodecanedioic acid.

[0036] Further preferably, the aromatic diacid is terephthalic acid.

[0037] Preferably, the diol is at least one of butanediol, propanediol, ethylene glycol or pentanediol.

[0038] Specifically, the biodegradable polyester can be at least one of poly(butylenesuccinate-co-terephthalate) (PBAT), poly(butylenesearate-co-terephthalate) (PBSeT), poly(butylenesuccinate-co-terephthalate) (PBST), poly(butylenesearate-co-adipate-co-terephthalate) (PBSeAT), poly(butylenesearate-co-succinate-co-terephthalate) (PBSeST), poly(butylenesuccinate-co-adipate-co-terephthalate) (PBSAT) or poly(propylenesuccinate-co-terephthalate) (PDAT).

[0039] Preferably, in the biodegradable polyester, the repeating units from terephthalic acid account for 30-55 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0040] Preferably, the biodegradable polyester has a molecular weight distribution coefficient of 1.1-3.0.

[0041] More preferably, the biodegradable polyester has a molecular weight distribution coefficient of 2-3; more preferably 2.6-2.8.

[0042] With the molecular weight distribution coefficient in this range, the biodegradable polyester contains a certain amount of small molecular weight biodegradable polyester, which can play a role in wetting, achieving faster diffusion of molecules and entanglement, so that the initial and long-term edge seal strength of the biodegradable material is better.

[0043] In the present application, polylactic acid can be commercially available or self-made.

[0044] The process of self-making the polylactic acid is as follows:

[0045] The lactide is first reacted in the presence of a catalyst at 130-140℃ and 1000-1400 Pa for 1-6 hours, and then reacted at 160-180℃ and 250-350 Pa for 1-12 hours, to obtain the polylactic acid.

[0046] The content of D-lactic acid units in the polylactic acid is controlled by controlling the content of D-lactide in the raw material (lactide).

[0047] The lactide comprises L-lactide and D-lactide, and the mass ratio of the L-lactide to the D-lactide is 50-80:10-50; the amount of the catalyst is 0.001%-1% of the mass of the lactide, and the catalyst comprises but is not limited to a tin-containing compound (such as stannous octoate).

[0048] Preferably, the molecules of the polylactic acid are composed of left-handed lactic acid units and right-handed lactic acid units.

[0049] In the present application, the content of D-lactic acid units in the polylactic acid can be 8, 10, 15, 20, 25, 30, 35, 40, 45 or 50 mol%.

[0050] Preferably, the content of D-lactic acid units in the polylactic acid is 19-50 mol%.

[0051] The content of D-lactic acid units in the polylactic acid is controlled in the range, and the initial and long-acting edge sealing strength of the obtained biodegradable material is better.

[0052] In the present application, the number average molecular weight of the polylactic acid can be 60,000, 70,000, 80,000, 90,000, 100,000, 110,000, 120,000, 130,000, 140,000, 150,000 or 160,000.

[0053] Preferably, the number average molecular weight of the polylactic acid is 60,000-130,000.

[0054] The number average molecular weight of the polylactic acid is controlled in the range, and the initial and long-acting edge sealing strength of the obtained biodegradable material is better.

[0055] Preferably, the D50 particle size of the inorganic filler is ≤5 μm, and the D98 particle size is ≤15 μm.

[0056] More preferably, the D50 particle size of the inorganic filler is 1-3 μm, and the D98 particle size is 3-10 μm.

[0057] The D50 particle size and the D98 particle size of the inorganic filler are controlled in the range, and the initial and long-acting edge sealing strength of the obtained biodegradable material is better.

[0058] In the present application, the inorganic filler particle size test method is determined by referring to the method of GB / T 19077.1 “Particle Size Analysis-Laser Diffraction Method”.

[0059] Preferably, the biodegradable material further comprises 0.1-2 parts of a compatibilizer. The addition of the compatibilizer can improve the initial and long-term edge seal strength of the obtained biodegradable material.

[0060] More preferably, the compatibilizer comprises, but is not limited to, a copolymer of styrene-methyl methacrylate.

[0061] Preferably, the biodegradable material further comprises 0.1-3 parts of other auxiliary agents.

[0062] Optionally, the other auxiliary agent is at least one of an antioxidant, a lubricant or a UV stabilizer.

[0063] Generally, the amount of each other auxiliary agent is: 0.01-0.3 parts by weight of the antioxidant, and 0.1-3 parts by weight of the UV stabilizer.

[0064] Optionally, the antioxidant is at least one of antioxidant 1010 or antioxidant 168.

[0065] Optionally, the lubricant comprises at least one of ethylene bis-stearamide, monoglyceride, oleic acid amide or erucic acid amide.

[0066] Optionally, the UV stabilizer is at least one of bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl) sebacate or 2-(2-hydroxy-3-tert-butyl-5-methylphenyl)-5-(2,4-dimethylphenyl)-2H-benzotriazol-4-one.

[0067] The preparation method of the biodegradable material comprises the following steps:

[0068] Mixing the components and melt extruding, to obtain the biodegradable material.

[0069] Preferably, the temperature of the melt extrusion is 150-170℃; the screw length-diameter ratio of the extruder for the melt extrusion is 35-45:1, and the screw rotation speed is 300-400 rpm.

[0070] The biodegradable material is used in the preparation of a biodegradable film or bag.

[0071] A biodegradable film or bag is prepared from the biodegradable film.

[0072] Compared with the prior art, the biodegradable material has the following advantages:

[0073] The biodegradable material can significantly improve the initial and long-term edge seal strength of the film prepared therefrom by matching the biodegradable polyester with a certain number average molecular weight and the polylactic acid with a certain number average molecular weight and D-lactic acid unit content. DETAILED DESCRIPTION

[0074] In order to more clearly, completely describe the technical solutions of the present application, the present application is further described in detail below through specific examples. It should be understood that the specific examples described herein are only used to explain the present application and are not used to limit the present application. Various changes can be made within the scope of the present application.

[0075] The part reagents selected for the embodiments and comparative examples of the present application are described as follows:

[0076] Biodegradable polyester 1#: self-made, polybutylene adipate terephthalate, the preparation method is as follows:

[0077] 1.8 kg of terephthalic acid, 2.0 kg of adipic acid, and 2.6 kg (excess) of 1,4-butanediol, 2.0 g of glycerol are all added into a 20 L reaction kettle, 190 ℃ (temperature T1) and stirred for 3 hours (time t1), then 0.01% acid alcohol total molar ratio of tetrabutyl titanate is added as a catalyst, the temperature is raised to 240 ℃ (temperature T2), the vacuum is opened, and the reaction is carried out for 8 hours (time t2), to obtain biodegradable polyester 1#. The number average molecular weight (M n ) of biodegradable polyester 1# is 70028, the molecular weight distribution coefficient (M W / M n ) is 2.0, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0078] Biodegradable polyester 2#: self-made, polybutylene adipate terephthalate, the difference between the preparation method of biodegradable polyester 2# and biodegradable polyester 1# is that the time t1 is 2 hours and the time t2 is 4 hours. The number average molecular weight (M n ) of biodegradable polyester 2# is 55872, the molecular weight distribution coefficient (M W / M n ) is 2.2, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0079] Biodegradable polyester 3#: self-made, polybutylene adipate terephthalate, the difference between the preparation method of biodegradable polyester 3# and biodegradable polyester 1# is that the time t1 is 6 hours and the time t2 is 16 hours. The number average molecular weight (M n ) of biodegradable polyester 3# is 97520, the molecular weight distribution coefficient (M W / M n ) is 1.9, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0080] Biodegradable polyester 4: self-made, polybutylene adipate terephthalate, the difference from the preparation method of biodegradable polyester 1# is that glycerol 3.0 g. The number average molecular weight (M n ) of biodegradable polyester 4# is 70338, the molecular weight distribution coefficient (M W / M n ) is 2.8, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0081] Biodegradable polyester 5: self-made, polybutylene adipate terephthalate, the difference from the preparation method of biodegradable polyester 1# is that glycerol 1.5 g. The number average molecular weight (M n ) of biodegradable polyester 5# is 70580, the molecular weight distribution coefficient (M W / M n ) is 1.6, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0082] Biodegradable polyester 6: self-made, polybutylene adipate terephthalate, the difference from the preparation method of biodegradable polyester 1# is that terephthalic acid 2.4 kg. The number average molecular weight (M n ) of biodegradable polyester 6# is 70610, the molecular weight distribution coefficient (M W / M n ) is 2.1, and the repeating units from terephthalic acid account for 54 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0083] Biodegradable polyester 7: self-made, polybutylene adipate terephthalate, the difference from the preparation method of biodegradable polyester 1# is that adipic acid is replaced by sebacic acid (2.0 kg). The number average molecular weight (M n ) of biodegradable polyester 7# is 70090, the molecular weight distribution coefficient (M W / M n ) is 2.0, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from diacid.

[0084] Biodegradable polyester 8: self-made, polybutylene adipate terephthalate, the difference from the preparation method of biodegradable polyester 1# is that glycerol 1.0 g. The number average molecular weight (M n ) of biodegradable polyester 8# is 70921, the molecular weight distribution coefficient (M W / M n) is 1.1, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from the dibasic acid.

[0085] Biodegradable polyester 9#: self-made, polybutylene adipate terephthalate, the difference between its preparation method and that of biodegradable polyester 1# is that the time t1 is 1 hour and the time t2 is 3 hours. The number average molecular weight (Mn) of biodegradable polyester 9# is 41072, the molecular weight distribution coefficient (Mw / Mn) is 2.1, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from the dibasic acid. n W n The number average molecular weight (Mn) of biodegradable polyester 9# is 41072, the molecular weight distribution coefficient (Mw / Mn) is 2.1, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from the dibasic acid.

[0086] Biodegradable polyester 10#: self-made, polybutylene adipate terephthalate, the difference between its preparation method and that of biodegradable polyester 1# is that the time t1 is 8 hours and the time t2 is 20 hours. The number average molecular weight (Mn) of biodegradable polyester 10# is 125730, the molecular weight distribution coefficient (Mw / Mn) is 2.0, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from the dibasic acid. n W n The number average molecular weight (Mn) of biodegradable polyester 10# is 125730, the molecular weight distribution coefficient (Mw / Mn) is 2.0, and the repeating units from terephthalic acid account for 45 mol% of the sum of the repeating units from terephthalic acid and the repeating units from the dibasic acid.

[0087] Polylactic acid 1#: self-made, its preparation method is as follows: PLLA / PDLA copolymer, self-made, 80 parts by weight of pure L-lactide (L content ≥ 99.5%, same below) and 20 parts by weight of pure D-lactide (D content is about 50%, same below) are mixed, stannous octoate (0.1 wt% relative to the total amount of lactide) is added, ring-opening polymerization is carried out, first at a reaction temperature of 135°C and a reaction pressure of 1200 Pa for 4 hours (time t3), and then at a reaction temperature of 170°C and a reaction pressure of 300 Pa for 6 hours (time t4). Underwater pelletizing, crystallization and drying obtain polylactic acid 1#. The number average molecular weight of polylactic acid 1# is 125830, and the content of D-lactic acid units is 19.8%.

[0088] Polylactic acid 2#: self-made, the difference between its preparation method and that of polylactic acid 1# is that the amount of pure L-lactide is 90 parts by weight and the amount of pure D-lactide is 10 parts by weight. The number average molecular weight (Mn) of polylactic acid 2# is 129987, and the D content is 9.7%. n

[0089] Polylactic acid 3#: self-made, the difference between its preparation method and that of polylactic acid 1# is that the amount of pure L-lactide is 50 parts by weight and the amount of pure D-lactide is 50 parts by weight. The number average molecular weight (Mn) of polylactic acid 3# is 129987, and the D content is 9.7%.​​​​​n ) is 124926, and the content of D-lactic acid unit is 49.7%.

[0090] Poly-lactic acid 4#: self-made, the difference between the preparation method and poly-lactic acid 1# is that the time t3 is 2 hours, and the time t4 is 3 hours. The number average molecular weight (Mn) of poly-lactic acid 4# is 126985, and the content of D-lactic acid unit is 1.9%. n ) is 124926, and the content of D-lactic acid unit is 49.7%.

[0091] Poly-lactic acid 5#: self-made, the difference between the preparation method and poly-lactic acid 1# is that the time t3 is 6 hours, and the time t4 is 12 hours. The number average molecular weight (Mn) of poly-lactic acid 5# is 159976, and the content of D-lactic acid unit is 19.8%. n ) is 124926, and the content of D-lactic acid unit is 49.7%.

[0092] Poly-lactic acid 6#: self-made, the difference between the preparation method and poly-lactic acid 1# is that the time t3 is 8 hours, and the time t4 is 15 hours. The number average molecular weight (Mn) of poly-lactic acid 6# is 193970, and the content of D-lactic acid unit is 19.9%. n ) is 124926, and the content of D-lactic acid unit is 49.7%.

[0093] Poly-lactic acid 7#: self-made, the difference between the preparation method and poly-lactic acid 1# is that 98 parts by weight of pure L-type-lactide and 2 parts by weight of pure D-type-lactide are used for synthesis. The number average molecular weight (Mn) of poly-lactic acid 7# is 126985, and the content of D-lactic acid unit is 1.9%. n ) is 124926, and the content of D-lactic acid unit is 49.7%.

[0094] The content of D-lactic acid unit of poly-lactic acid can be detected according to the following steps: (1) 100±10 mg of ground and crushed poly-lactic acid sample is weighed and placed in a 25 mL pressure container inner barrel; (2) 10 mL of methanol and 1 drop of dilute sulfuric acid are added; (3) the pressure container is sealed and placed in a 150℃ constant temperature device for 4 hours; (4) the pressure container is taken out and cooled to room temperature before opening; (5) the sample solution is filtered through a membrane filter (pore size 0.22 or 0.45 μm) and transferred to a gas chromatography special sample vial, and the operation is carried out according to the manufacturer's instructions; (6) the content of D-lactic acid unit is calculated according to the peak area ratio.

[0095] The inorganic filler is obtained by or without grinding and / or screening treatment of the following raw materials.

[0096] Inorganic filler 1#: calcium carbonate, Xirong, ACC-815, D50 is 1.6 μm, and D98≤8.4 μm;

[0097] Inorganic filler 2#: talc powder, Guangxi Longsheng Huamei Talc Development Co., Ltd., D50 is 2.5 μm, and D98≤4 μm;

[0098] Inorganic filler 3#: calcium carbonate, Dongyuan, DY-66N36, D50 is 4.1 μm, D98≤14.1 μm;

[0099] The particle size of the inorganic filler can be determined according to GB / T 19077.1 "Particle Size Analysis-Laser Diffraction Method".

[0100] Compatibility agent: styrene-methacrylate copolymer, Jiaiyong, HPC-3510P;

[0101] Other auxiliary agent 1#: ethylene bis-stearamide, commercially available;

[0102] Unless otherwise specified, each component (such as other auxiliary agent 1#) selected in each parallel example and comparative example is the same commercially available product.

[0103] The biodegradable materials provided by each embodiment and comparative example of the present application are respectively made into a film with a thickness of 40 μm by a film blowing machine, and the sealing edge is performed at 350℃ with a speed of 80 / min. The performance of the film after sealing edge is determined according to the following test method:

[0104] 1) The grade of initial sealing edge strength: the sealing edge strength is tested by tensile strength, and the tensile fracture position is not easy to appear at the non-sealing position. Therefore, the hand tearing sealing edge grade is used for evaluation. The evaluation standard is shown in Table 1: the higher the grade, the better the sealing edge strength. The film of each embodiment and comparative example is measured for an average of 20 times, and the average value is obtained.

[0105] Table 1

[0106]

[0107] 2) The grade of long-acting sealing edge strength: the biodegradable material of each embodiment and comparative example is made into a film with a thickness of 40 μm, and the sealing edge is performed at 350℃ with a speed of 80 / min. After sealing edge, the film is placed in an environment of 25℃ and 55% RH for 3 months, and then the grade of long-acting sealing edge strength is evaluated according to the evaluation method of the grade of initial sealing edge strength.

[0108] The biodegradable material of the embodiment and comparative example of the present application is prepared by the following preparation method:

[0109] Each component is weighed according to the formula, mixed uniformly, and then put into a twin-screw extruder for melt extrusion and granulation to obtain a biodegradable material. The temperature of the first to tenth zones of the twin-screw extruder is 150℃, 155℃, 160℃, 165℃, 165℃, 165℃, 165℃, 165℃, 170℃ and 170℃, respectively; the screw length-diameter ratio is 40:1, and the screw rotation speed is 300 rpm.

[0110] Examples 1-16

[0111] Examples 1-16 provide a series of biodegradable materials whose formulations are shown in Table 2 and Table 3.

[0112] Table 2 Formulations (parts by weight) of Examples 1-10

[0113]

[0114] Table 3 Formulations (parts by weight) of Examples 11-16

[0115]

[0116]

[0117] Comparative Examples 1-4

[0118] Comparative Examples 1-4 provide a series of biodegradable materials whose formulations are shown in Table 4.

[0119] Table 4 Formulations (parts by weight) of Comparative Examples 1-4

[0120]

[0121] The properties of the biodegradable materials of each example and comparative example were determined according to the test methods mentioned above, and the test results are shown in Table 5.

[0122] Table 5 Test results of the properties of the biodegradable materials of each example and comparative example

[0123]

[0124]

[0125] From Table 5, it can be seen that:

[0126] The initial edge seal strength of the biodegradable materials of Examples 1-16 is rated at 4.3 or higher, and the long-term edge seal strength is rated at 3.0 or higher, indicating that the biodegradable materials of the present application not only have good initial edge seal strength, but also have good long-term edge seal strength.

[0127] The number average molecular weight of the biodegradable polyester added in Comparative Examples 1 and 2 is too small or too large, the initial edge seal strength of the biodegradable materials is poor, the long-term edge seal strength of the biodegradable material of Comparative Example 1 is not good, and the long-term edge seal strength of the biodegradable material of Comparative Example 2 is poor. The number average molecular weight of the polylactic acid added in Comparative Example 3 is too large, and the D content of the polylactic acid added in Comparative Example 4 is too low, and the initial edge seal strength and long-term edge seal strength of the biodegradable materials obtained from both are poor.

[0128] Obviously, the above embodiments of the present application are merely exemplary but not intended to limit the embodiments of the present application. Based on the above description, any other variations or changes can be made by those skilled in the art without departing from the spirit and principles of the present application. It is not necessary to list all the embodiments here. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall fall within the scope of the claims of the present application.

Claims

1. A biodegradable material, characterized in that, The biodegradable material comprises the following components in parts by weight: 85~92 parts of biodegradable polyester, 3~8 parts of polylactic acid, 0~8 parts of inorganic filler; The biodegradable polyester is polybutylene adipate terephthalate, and the number average molecular weight of the biodegradable polyester is 50000~100000. The number average molecular weight of the polylactic acid is 60000~160000, and the content of D-lactic acid unit in the polylactic acid is 8~51mol%.

2. The biodegradable material of claim 1, wherein, The molecular weight distribution coefficient of the biodegradable polyester is 1.1~3.

0.

3. The biodegradable material of claim 1, wherein, The D50 particle size of the inorganic filler is ≤5μm, and the D98 particle size is ≤15μm.

4. The biodegradable material of claim 1, wherein, The biodegradable material further comprises 0.1~1 parts of compatibilizer.

5. The biodegradable material of claim 1, wherein, The biodegradable material further comprises 0.1~2 parts of lubricant.

6. The method of producing a biodegradable material according to any one of claims 1 to 5, characterized by, The method comprises the following steps: Mixing and melt extruding the components to obtain the biodegradable material.

7. Use of the biodegradable material according to any one of claims 1~5 in the preparation of biodegradable film or bag.

8. A biodegradable film or pouch characterized in that, Prepared from the biodegradable material according to any one of claims 1~5.

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