A low-odor biodegradable composition and methods of making and using the same

Abstract

The present application relates to a kind of low odor biodegradable composition and its preparation method and application, the low odor biodegradable composition includes 70~78 parts by weight polybutylene adipate terephthalate, 5~7 parts by weight polylactic acid, 4~6 parts by weight nano layered montmorillonite and 13~17 parts by weight superfine calcium carbonate;The average grain thickness of nano layered montmorillonite perpendicular to (001) crystal face direction is 0.9~3.3nm;The D 98 Particle size≤13 μm.The biodegradable composition provided by the present application not only can significantly reduce the odor of the product, but also has a higher 100% longitudinal modulus of elongation, which improves the resistance to deformation of the product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engineering plastics, in particular to a low-odor biodegradable composition and a preparation method and application thereof. BACKGROUND

[0002] With the increasing awareness of environmental protection, the problem of white pollution has been increasingly concerned. White pollution is mainly caused by non-degradable plastic products such as polyethylene (PE) and polypropylene (PP), which are difficult to decompose in the natural environment and have a serious impact on the ecological system. Therefore, the use of biodegradable materials to gradually replace traditional plastics is the current development trend.

[0003] Polybutylene adipate terephthalate (PBAT) and polylactic acid (PLA) are common biodegradable materials, which can be used to manufacture film bag products after being compounded with inorganic fillers. However, consumers generally feedback that the film bags made of biodegradable materials have a poor odor experience compared to traditional PE bags, which to some extent hinders the promotion and application of biodegradable materials, especially in the fields of catering bags, take-out bags and beverage bags.

[0004] In addition, biodegradable film bags are prone to deformation during use due to external forces such as stretching, extrusion, etc., which affects their performance and service life. The 100% longitudinal modulus of film bags is an important indicator to measure their resistance to deformation. However, the prior art has not fully solved the problem of deformation of film bags caused by external forces during use, and it cannot achieve a high 100% longitudinal modulus.

[0005] Therefore, it is a technical problem to be solved at present to provide a biodegradable material with low odor, biodegradability and good 100% longitudinal modulus. SUMMARY

[0006] In view of the above problems, the purpose of the present application is to provide a low-odor biodegradable composition and a preparation method and application thereof. Compared with the prior art, the biodegradable composition provided by the present application not only can significantly reduce the odor of the product, but also has a high 100% longitudinal modulus, thereby improving the resistance to deformation of the product.

[0007] To achieve the purpose of the present application, the following technical solutions are adopted:

[0008] In a first aspect, the present application provides a low-odor biodegradable composition, which comprises 70-78 parts by weight of polybutylene adipate terephthalate, 5-7 parts by weight of polylactic acid, 4-6 parts by weight of nano-layered montmorillonite, and 13-17 parts by weight of ultra-fine calcium carbonate.

[0009] The average grain thickness of the nanometer layered montmorillonite is 0.9-3.3 nm in the direction perpendicular to the (001) crystal face.

[0010] The D50 of the superfine calcium carbonate is 0.5-1.5 μm. 98 The particle size is ≤13 μm.

[0011] In the present application, 70-78 parts of polybutylene terephthalate, for example, can be 70 parts, 70.5 parts, 71 parts, 71.5 parts, 72 parts, 72.5 parts, 73 parts, 73.5 parts, 74 parts, 74.5 parts, 75 parts, 75.5 parts, 76 parts, 76.5 parts, 77 parts, 77.5 parts, 78 parts or a range between any of the above values.

[0012] In the present application, 5-7 parts of polylactic acid, for example, can be 5 parts, 5.2 parts, 5.4 parts, 5.6 parts, 5.8 parts, 6 parts, 6.2 parts, 6.4 parts, 6.6 parts, 6.8 parts, 7 parts or a range between any of the above values.

[0013] In the present application, 4-6 parts of nanometer layered montmorillonite, for example, can be 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, 5.2 parts, 5.4 parts, 5.6 parts, 5.8 parts, 6 parts or a range between any of the above values.

[0014] In the present application, 13-17 parts of superfine calcium carbonate, for example, can be 13 parts, 13.2 parts, 13.4 parts, 13.6 parts, 13.8 parts, 14 parts, 14.2 parts, 14.4 parts, 14.6 parts, 14.8 parts, 15 parts, 15.2 parts, 15.4 parts, 15.6 parts, 15.8 parts, 16 parts, 16.2 parts, 16.4 parts, 16.6 parts, 16.8 parts, 17 parts or a range between any of the above values.

[0015] In the present application, the average grain thickness of the nanometer layered montmorillonite is 0.9-3.3 nm in the direction perpendicular to the (001) crystal face, for example, can be 0.9 nm, 0.95 nm, 1.0 nm, 1.05 nm, 1.1 nm, 1.15 nm, 1.2 nm, 1.25 nm, 1.3 nm, 1.4 nm, 1.5 nm, 1.6 nm, 1.7 nm, 1.8 nm, 1.9 nm, 2.0 nm, 2.1 nm, 2.2 nm, 2.3 nm, 2.4 nm, 2.5 nm, 2.6 nm, 2.7 nm, 2.8 nm, 2.9 nm, 3.0 nm, 3.1 nm, 3.2 nm, 3.3 nm or a range between any of the above values.

[0016] In the present application, the D50 of the superfine calcium carbonate is 0.5-1.5 μm. 98The particle size is less than or equal to 13 microns, for example, 13 microns, 12.8 microns, 12.6 microns, 12.4 microns, 12.2 microns, 12 microns, 11.8 microns, 11.6 microns, 11.4 microns, 11.2 microns, 11 microns, 10.8 microns, 10.6 microns, 10.4 microns, 10.2 microns, 10 microns, 9.8 microns, 9.6 microns, 9.4 microns, 9.2 microns, 9 microns, 8.8 microns, 8.6 microns, 8.4 microns, 8.2 microns, 8 microns, or a range between any of the aforementioned values.

[0017] The low-odor biodegradable composition provided by the present application has a synergistic effect of nano-layered montmorillonite and superfine calcium carbonate, and the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal face direction and the D 98 The regulation of the particle size can make the superfine-sized powder densely dispersed in the composition, reduce the shearing effect of the inorganic fillers such as montmorillonite and calcium carbonate on the polybutylene terephthalate during melt blending, and reduce the breakage of the polymer chain and the emission of odor molecules.

[0018] In the present application, the test method of the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal face direction is as follows: the nano-layered montmorillonite is tested by XRD, and the test conditions are as follows: a CuKα target (λ=0.154 nm) is selected, the voltage is 30 kV, the current is 20 mA, the scanning range is 5-50° (2θ), the scanning speed is 0.5° / min, the XRD diffraction peak is obtained, and the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal face direction is calculated by reverse calculation through the broadening phenomenon of the diffraction peak by using the Scherrer formula. The Scherrer formula is as follows:

[0019] ;

[0020] wherein D represents the average grain thickness (nm) perpendicular to the (001) crystal face direction;

[0021] K represents a shape constant, which is 0.89;

[0022] λ represents the X-ray wavelength, which is 0.154 nm;

[0023] β represents the half-height width (FWHM, which needs to be converted to radian system) of the diffraction peak;

[0024] θ represents the diffraction angle (Bragg angle, unit: radian).

[0025] In the present application, the D98 The particle size is determined according to the method specified in GB / T 19077.1 "Particle size analysis - Laser diffraction method".

[0026] Preferably, the average crystal grain thickness of the nanolayered montmorillonite perpendicular to the (001) crystal face direction is 1-2.9 nm, preferably 1.2-2.2 nm.

[0027] Preferably, the D50 of the ultrafine calcium carbonate is 0.1-0.5 μm, preferably 0.2-0.4 μm. 98 The particle size is ≤ 11 μm, preferably ≤ 9 μm.

[0028] Preferably, the polybutylene adipate terephthalate has a melt index of 1-10 g / 10 min, for example 1 g / 10 min, 1.2 g / 10 min, 1.5 g / 10 min, 1.8 g / 10 min, 2 g / 10 min, 2.2 g / 10 min, 2.4 g / 10 min, 2.5 g / 10 min, 2.6 g / 10 min, 2.8 g / 10 min, 3 g / 10 min, 3.2 g / 10 min, 3.4 g / 10 min, 3.5 g / 10 min, 3.6 g / 10 min, 3.8 g / 10 min, 4 g / 10 min, 4.2 g / 10 min, 4.4 g / 10 min, 4.5 g / 10 min, 4.6 g / 10 min, 4.8 g / 10 min, 5 g / 10 min, 5.2 g / 10 min, 5.4 g / 10 min, 5.5 g / 10 min, 5.6 g / 10 min, 5.8 g / 10 min, 6 g / 10 min, 6.2 g / 10 min, 6.4 g / 10 min, 6.5 g / 10 min, 6.6 g / 10 min, 6.8 g / 10 min, 7 g / 10 min, 7.5 g / 10 min, 8 g / 10 min, 8.5 g / 10 min, 9 g / 10 min, 9.5 g / 10 min, 10 g / 10 min or a range between any of the aforementioned values, preferably 3-6 g / 10 min, further preferably 3.5-5 g / 10 min.

[0029] In the present application, the melt index of the polybutylene adipate terephthalate is tested according to ISO 1133 standard, the test being carried out at 190°C and under a load of 2.16 kg.

[0030] In the present application, by preferably controlling the melt index of polybutylene adipate terephthalate, the odor can be further reduced and the 100% longitudinal modulus of elasticity can be improved. When the melt index of polybutylene adipate terephthalate is too low, the molecular chain of the polyester is too long, the molecular chain movement is difficult, and the physical entanglement with polylactic acid is easy to form, which can easily lead to molecular chain rupture under the effect of blending shear, forming small molecules, resulting in increased odor and decreased 100% longitudinal modulus of elasticity. When the melt index of polybutylene adipate terephthalate is too high, the viscosity of the blending system is not enough, and the wrapping and dispersion of nano-layered montmorillonite and ultra-fine calcium carbonate are insufficient, which can easily cause the agglomeration of the powder, resulting in decreased 100% longitudinal modulus of elasticity.

[0031] In the present application, the acid value of the polybutylene adipate terephthalate is 10-15 mol / t, for example, it can be 10 mol / t, 11 mol / t, 12 mol / t, 13 mol / t, 14 mol / t, 15 mol / t or a range between any of the above values.

[0032] In the present application, the acid value of the polylactic acid is 5-20 mol / t, for example, it can be 5 mol / t, 6 mol / t, 7 mol / t, 8 mol / t, 9 mol / t, 10 mol / t, 11 mol / t, 12 mol / t, 13 mol / t, 14 mol / t, 15 mol / t, 16 mol / t, 17 mol / t, 18 mol / t, 19 mol / t, 20 mol / t or a range between any of the above values.

[0033] In the present application, the acid value of the polybutylene adipate terephthalate or polylactic acid is determined by referring to the method A of 5.4 in GB / T14190-2017.

[0034] Preferably, the polylactic acid comprises a PLLA / PDLA copolymer.

[0035] In the present application, the molar content of D-lactic acid in the PLLA / PDLA copolymer is 0.5-6%, for example, it can be 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.4%, 1.6%, 1.8%, 2%, 2.2%, 2.4%, 2.6%, 2.8%, 3%, 3.2%, 3.4%, 3.6%, 3.8%, 4%, 4.2%, 4.4%, 4.6%, 4.8%, 5%, 5.2%, 5.4%, 5.6%, 5.8%, 6% or a range between any of the above values, preferably 1-5%, further preferably 2-4%.

[0036] In the present application, the method for measuring the molar content of D-lactic acid in the PLLA / PDLA copolymer is as follows: the PLLA / PDLA copolymer sample is subjected to ester exchange reaction with methanol in a pressure container at 150°C to degrade the PLLA / PDLA copolymer, the degraded sample is analyzed by gas chromatography (GC), the peak areas of L-lactic acid methyl ester and D-lactic acid methyl ester are detected, and the molar content of D-lactic acid in the PLLA / PDLA copolymer is calculated, and the calculation formula is as follows:

[0037] ;

[0038] wherein D-Lactic Acid represents the molar content of D-lactic acid in the PLLA / PDLA copolymer;

[0039] A DML represents the peak area of D-lactic acid methyl ester;

[0040] A LML represents the peak area of L-lactic acid methyl ester.

[0041] The molar content of D-lactic acid obtained from each gas chromatography run is sampled multiple times and statistically analyzed, and the molar content of D-lactic acid in the PLLA / PDLA copolymer is the average value of multiple test results.

[0042] In the present application, the molar content of D-lactic acid in the PLLA / PDLA copolymer can improve the compatibility with the system, which is beneficial to reducing odor and improving 100% longitudinal modulus of elongation.

[0043] Preferably, the low-odor biodegradable composition further comprises an opening agent.

[0044] Preferably, the low-odor biodegradable composition comprises 0.2-0.8 parts of the opening agent by weight, for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, or a range between any of the above values.

[0045] Preferably, the opening agent comprises at least one of talc, zeolite or barium sulfate, preferably talc and / or barium sulfate.

[0046] In the present application, although the opening agent is inorganic material such as talc, zeolite or barium sulfate, the amount of addition is very small, so the particle size does not affect the odor.

[0047] Preferably, the low-odor biodegradable composition further comprises a lubricant.

[0048] Preferably, the low odor biodegradable composition comprises 0.2 to 0.8 parts by weight of the lubricant, for example, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, or a range between any of the foregoing.

[0049] Preferably, the lubricant comprises at least one of erucamide, oleamide, glycerol monostearate, pentaerythritol stearate, polyethylene wax, ethylene bis-stearamide, or a silicone lubricant.

[0050] In the present application, the silicone lubricant can be any commonly used silicone lubricant in the art, for example, polydimethylsiloxane, silicone powder, silicone ester, etc.

[0051] In a second aspect, the present application provides a method for preparing the low odor biodegradable composition according to the first aspect of the present application, the method comprising the following steps:

[0052] After melt blending of the components, the low odor biodegradable composition is obtained by extrusion granulation.

[0053] In the present application, the melt blending includes but is not limited to being carried out in an extruder, which generally comprises a first feeding section, a second feeding section, and a melt blending section arranged in sequence.

[0054] Preferably, the temperature of the first feeding section is 80 to 90°C, for example, 80°C, 82°C, 84°C, 86°C, 88°C, 90°C, or a range between any of the foregoing.

[0055] Preferably, the temperature of the second feeding section is 90 to 130°C, for example, 90°C, 95°C, 100°C, 105°C, 110°C, 120°C, 130°C, or a range between any of the foregoing.

[0056] Preferably, the temperature of the melt blending is 180 to 210°C, for example, 180°C, 190°C, 200°C, 210°C, or a range between any of the foregoing.

[0057] In a third aspect, the present application provides a low odor biodegradable product formed from the low odor biodegradable composition according to the first aspect of the present application.

[0058] Preferably, the low odor biodegradable product comprises a film or a bag.

[0059] Preferably, the film is formed by using the low odor biodegradable composition through a melt-blowing method.

[0060] Preferably, the bag is obtained by heat sealing the film.

[0061] The numerical range described in the present application includes not only the point values listed above, but also any point values between the above numerical ranges that are not listed, and the present application does not exhaustively list the specific point values included in the range for the sake of brevity and simplicity.

[0062] Compared with the prior art, the present application has the following beneficial effects:

[0063] In the low-odor biodegradable composition provided by the present application, the nano-layered montmorillonite and the superfine calcium carbonate synergistically act, and the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal face direction and the D 98 The regulation of the particle size not only enables the superfine-sized powder to be densely dispersed in the composition, but also reduces the shearing effect of the inorganic fillers such as montmorillonite and calcium carbonate on the polybutylene adipate terephthalate during melt blending, and reduces the emission of odor molecules; at the same time, the control of the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal face direction can induce the intercalation effect of the polymer, and at the same time, improve the 100% longitudinal modulus of the biodegradable composition. DETAILED DESCRIPTION

[0064] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations on the present application.

[0065] In the present application, the materials used in the examples and comparative examples are all obtained from commercial sources or prepared by conventional methods, and if not specifically stated, the materials used in the present application are as follows:

[0066] Polybutylene adipate terephthalate (PBAT):

[0067] PBAT1: The PBAT of model A400 from Zhuhai Jinhang Biomaterials Co., Ltd. was dried and devolatilized in a drying tank, the drying temperature was 80℃, and the time was 4h, to obtain PBAT1, the melt index of which was 4.0g / 10min, and the acid value was 15mol / t.

[0068] PBAT2, self-made, the preparation method comprising: esterification of 20 kg of terephthalic acid and 13 kg of 1,4-butanediol at 195 °C for 2 h, during which the generated esterification water is continuously discharged to obtain terephthalic acid butanediol ester oligomer; the terephthalic acid butanediol ester oligomer, 20 kg of adipic acid and 13 kg of 1,4-butanediol are added into a 200 L reactor for esterification reaction, and the reaction is carried out at 195 °C for 4 h, during which the generated esterification water is continuously discharged, then 0.3 kg of tetrabutyl titanate is added as a catalyst, the temperature is raised to 240 °C, the reaction is carried out under a vacuum pressure of 290 Pa for 15 h, further 0.01 kg of diphenyl methane diisocyanate is added for chain extension, and the reaction is carried out for 1 h to obtain the PBAT2, the melt index of which is 1.8 g / 10 min and the acid value is 14 mol / t.

[0069] PBAT3, self-made, the preparation method comprising: esterification of 20 kg of terephthalic acid and 13 kg of 1,4-butanediol at 195 °C for 2 h, during which the generated esterification water is continuously discharged to obtain terephthalic acid butanediol ester oligomer; the terephthalic acid butanediol ester oligomer, 20 kg of adipic acid and 13 kg of 1,4-butanediol are added into a 200 L reactor for esterification reaction, and the reaction is carried out at 195 °C for 2 h, during which the generated esterification water is continuously discharged, then 0.3 kg of tetrabutyl titanate is added as a catalyst, the temperature is raised to 240 °C, the reaction is carried out under a vacuum pressure of 290 Pa for 8 h to obtain the PBAT3, the melt index of which is 8.5 g / 10 min and the acid value is 15 mol / t.

[0070] Polylactic acid:

[0071] PLLA / PDLA copolymer, KB600 NF20 type, D-type lactic acid, the mole content of which is 1.6%, and the acid value of which is 6.0 mol / t, Zhuhai Jinshan Biomaterials Co., Ltd.

[0072] Nano-layered montmorillonite:

[0073] Montmorillonite 1, self-made, DK5, Zhejiang Fenghong New Material Co., Ltd., is subjected to ball milling by using a planetary ball mill, the rotation speed is set to 100 r / min, and the grinding is carried out for 1 h to obtain the montmorillonite 1, the average grain thickness of which is 1.4 nm in the direction perpendicular to the (001) crystal face, and the D50 particle size of which is 9.6 μm.

[0074] Montmorillonite 2, I.3PS, the average grain thickness of which is 2.2 nm in the direction perpendicular to the (001) crystal face, and the D50 particle size of which is 15.2 μm, Nanocor Co., Ltd., USA.

[0075] Montmorillonite 3, self-made, taking I.44P of NANOCOR Company of USA, using a planetary ball mill to perform ball milling, setting the rotating speed at 100 r / min, and performing grinding for 3 h to obtain the montmorillonite 3, the average grain thickness in the direction perpendicular to the (001) crystal face is 2.0 nm, and the D50 particle size is 10.3 μm.

[0076] Montmorillonite 4, self-made, taking DK5 of Zhejiang Fenghong New Material Co., Ltd., using a planetary ball mill to perform ball milling, setting the rotating speed at 100 r / min, and performing grinding for 4 h to obtain the montmorillonite 4, the average grain thickness in the direction perpendicular to the (001) crystal face is 1.0 nm, and the D50 particle size is 9.9 μm.

[0077] Montmorillonite 5, self-made, taking K100 of Guangzhou Yinshu Flame Retardant Material Co., Ltd., using a planetary ball mill to perform ball milling, setting the rotating speed at 100 r / min, and performing grinding for 20 min to obtain the montmorillonite 5, the average grain thickness in the direction perpendicular to the (001) crystal face is 2.9 nm, and the D50 particle size is 10.3 μm.

[0078] Montmorillonite 6, DK10, Zhejiang Fenghong New Material Co., Ltd., the average grain thickness in the direction perpendicular to the (001) crystal face is 3.6 nm, and the D50 particle size is 9.5 μm.

[0079] Montmorillonite 7, self-made, taking I.3PS of NANOCOR Company of USA, using a planetary ball mill to perform ball milling, setting the rotating speed at 100 r / min, and performing grinding for 24 h, the average grain thickness in the direction perpendicular to the (001) crystal face is 0.8 nm, and the D50 particle size is 9.4 μm.

[0080] Superfine calcium carbonate:

[0081] Calcium carbonate 1, 1T-CU, Omya Company, D 98 The particle size is 8 μm.

[0082] Calcium carbonate 2, self-made, taking 5T-JI of Omya Company, using a planetary ball mill to perform ball milling, setting the rotating speed at 100 r / min, and performing grinding for 3 h to obtain the calcium carbonate 2, D 98 The particle size is 15.5 μm.

[0083] Opening agent: talcum powder, TYT-777A, Liaoning Haicheng Tianyuan Company, the average particle size is 5.1 μm.

[0084] Lubricant: erucic acid amide, CRODAMIDE ER-CH-MB-(SI), Huitaixipu Chemical (Sichuan) Co., Ltd.

[0085] Examples 1~12, Comparative Examples 1~3 respectively provide a low odor biodegradable composition, the composition of which is shown in Tables 1~2, in parts by weight, wherein " / " indicates that there is no such component in the formulation.

[0086] In the present application, unless otherwise specified, the preparation method of the low odor biodegradable composition comprises: melt blending the components in an extruder and then extruding and granulating, the temperature of the extruder is set from the feeding port to the die head at 80℃, 120℃, 190℃, 190℃, 190℃, 190℃, 190℃, 190℃, 190℃, 190℃, 200℃ and 205℃, respectively, to obtain the low odor biodegradable composition.

[0087] Table 1

[0088]

[0089] Table 2

[0090]

[0091] Performance test:

[0092] The particles of the low odor biodegradable composition are melt blown to form a film, a film blowing machine with a die diameter of 70mm is selected, the temperature of the film blowing machine is set from the feeding port to the die head at 100℃, 140℃, 150℃, 150℃ and 155℃, respectively, the film blowing frequency is 25Hz, to obtain a film with a thickness of 15±1μm and a width of 300±10mm.

[0093] (1) Odor grade: reference to Volkswagen PV 3900-2000 standard. Cut 50g of film sample, put it into a 1L capacity odor bottle, seal with aluminum foil, heat in an oven at 80±2℃ for 2h, cool to 60±5℃ after taking out, then open the odor bottle cap, and quickly test the odor rating by at least 3 people, the rating standard is shown in Table 3, different levels of intermediate levels (such as 5.5, 4.5, 3.5) can be rated according to the specific circumstances, and the average value of multiple people is taken.

[0094] Table 3

[0095]

[0096] (2) 100% longitudinal modulus of elongation:

[0097] According to GB / T 1040.3 standard, a film with a thickness of 15μm is prepared, based on the film tensile test standard, the tensile strength when the film elongation reaches 100% is recorded, i.e. 100% longitudinal modulus of elongation, at a tensile speed of 300mm / min. Test five times and take the average value.

[0098] The specific test results are shown in Table 4.

[0099] Table 4

[0100]

[0101] As shown in Table 4, in the low-odor biodegradable composition provided by the application, the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal surface direction and the D 98 The regulation of the particle size can reduce the emission of odor molecules and improve the 100% longitudinal modulus of the biodegradable composition.

[0102] The above merely provides a specific implementation of the application, but the protection scope of the application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the application, which can be easily thought of by those skilled in the art, falls within the protection scope and disclosure scope of the application.

Claims

1. A low-odor, biodegradable composition, characterized in that, By weight, the low-odor biodegradable composition comprises 70-78 parts of polybutylene adipate terephthalate, 5-7 parts of polylactic acid, 4-6 parts of nano-layered montmorillonite and 13-17 parts of ultrafine calcium carbonate. The average grain thickness of the nanolayered montmorillonite perpendicular to the (001) crystal plane is 1~3.3 nm; The D of the ultrafine calcium carbonate 98 The particle size is 8~13μm; The method for testing the average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal plane is as follows: XRD is used to test the nano-layered montmorillonite. The test conditions are: CuKα target, λ=0.154nm, voltage 30kV, current 20mA, scanning range 2θ is 5~50°, and scanning speed is 0.5° / min. XRD diffraction peaks are obtained. The average grain thickness of the nano-layered montmorillonite perpendicular to the (001) crystal plane is calculated by back-calculating the Scherrer formula based on the broadening phenomenon of the diffraction peaks. The Scherrer formula is as follows: ;in, D The average grain thickness is expressed in nm in the direction perpendicular to the (001) crystal plane. K This represents the shape constant, which is 0.

89. λ This indicates the X-ray wavelength, which is 0.154 nm. β The FWHM (Full width at half maximum) of the diffraction peak is expressed in radians. θ This represents the diffraction angle, also known as the Bragg angle, and is expressed in radians. The D of the ultrafine calcium carbonate 98 Particle size was determined according to the method specified in GB / T 19077.1 "Particle size analysis by laser diffraction".

2. The low-odor, biodegradable composition according to claim 1, characterized in that, The average grain thickness of the nanolayered montmorillonite perpendicular to the (001) crystal plane is 1~2.9 nm.

3. The low-odor, biodegradable composition according to claim 1, characterized in that, The D of the ultrafine calcium carbonate 98 Particle size ≤11μm.

4. The low-odor, biodegradable composition according to claim 1, characterized in that, The melt index of the polybutylene adipate terephthalate is 1~10 g / 10 min.

5. The low-odor, biodegradable composition according to claim 1, characterized in that, The polylactic acid includes PLLA / PDLA copolymer.

6. The low-odor, biodegradable composition according to claim 1, characterized in that, The low-odor, biodegradable composition also includes an opening agent; The low-odor biodegradable composition comprises 0.2 to 0.8 parts by weight of an opening agent; The opening agent includes at least one of talc, zeolite, or barium sulfate.

7. The low-odor, biodegradable composition according to claim 1, characterized in that, The low-odor, biodegradable composition also includes a lubricant; The low-odor biodegradable composition comprises 0.2 to 0.8 parts by weight of lubricant; The lubricant includes at least one of erucamide, oleamide, glyceryl monostearate, pentaerythritol stearate, polyethylene wax, ethylene bis-stearamide, or silicone lubricants.

8. A method for preparing a low-odor, biodegradable composition according to any one of claims 1 to 7, characterized in that, The preparation method includes the following steps: The components are melt-blended and then extruded and granulated to obtain the low-odor, biodegradable composition.

9. A low-odor, biodegradable product, characterized in that, The low-odor biodegradable product is formed from the low-odor biodegradable composition according to any one of claims 1 to 7.

10. The low-odor, biodegradable product according to claim 9, characterized in that, The low-odor, biodegradable products include films or bags.

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