Biomass-filled garbage bag capable of being rapidly degraded and preparation method of biomass-filled garbage bag

Abstract

The invention discloses a rapid degradation garbage bag filled with biomass and a preparation method of the rapid degradation garbage bag. The rapid degradation garbage bag comprises the following components in parts by weight: 100 parts of a degradable polymer; 5-20 parts of a biomass rapid degradation agent; 1-5 parts of a rapid degradation aid; 1-2 parts of a surface modifier; wherein the raw materials of the biomass rapid degradation agent comprise biomass straws and bicarbonate. The rapidly degradable garbage bag provided by the invention has the characteristics of low cost, excellent mechanical properties, high degradation rate and the like, the tensile strength is greater than 20MPa, the elongation at break is greater than 250%, the rapidly degradable garbage bag can be disintegrated within 7 days and completely composted and degraded within 90 days when in a high-humidity environment (such as a garbage dump) with the humidity of 85RH% or above, the degradation rate reaches 90% or above, the purpose of rapid degradation is achieved, and the rapidly degradable garbage bag is suitable for popularization and application. And compared with other rapid degradation materials, the biomass rapid degradation agent enables the material to better meet the requirements of environmental protection and energy conservation.

Description

Technical Field

[0001] The present invention relates to the technical field of fully biodegradable films, and more specifically to a biomass-filled fast-degradable garbage bag and a preparation method thereof. Background Art

[0002] Biodegradable plastics are one of the important solutions to plastic pollution. However, most of the biodegradable raw materials today are not only petroleum-based and too expensive, but also not degrade fast enough. All of these have affected the promotion and application of biodegradable plastics. Therefore, it is urgent to develop low-cost, quickly degradable disposable packaging film bags (such as kitchen waste bags).

[0003] In order to find rapidly degradable materials, blending biodegradable polymers with rapidly degradable fillers (such as starch) is a simple and low-cost method. For example, CN116731491A discloses a rapidly degradable environmentally friendly plastic and a preparation method thereof, which uses starch and polylactic acid as a composite substrate, and vermiculite as an auxiliary agent to promote the affinity of the two materials. Due to the addition of starch, the material can lose 50-55% of its mass after being buried in the soil for 30 days, but it still faces the problem that starch is very sensitive to environmental humidity and thus affects mechanical properties, which requires higher requirements for starch modification, thereby increasing process difficulty and cost. Therefore, how to develop a low-cost disposable packaging film bag material that is both usable and rapidly degradable is still a key technical problem. Summary of the invention

[0004] One object of the present invention is to provide a biomass-filled fast-degradable garbage bag. The fast-degradable garbage bag provided by the present invention has low cost and excellent mechanical properties, with a tensile strength of >20MPa and a breaking elongation of >250%. When placed in a high humidity environment (such as a landfill) with a humidity of more than 85RH%, it can disintegrate within 7 days and be completely composted and degraded within 90 days, with a degradation rate of more than 90%, thereby achieving the purpose of fast degradation.

[0005] Another object of the present invention is to provide a method for preparing the fast-degradable garbage bag as described above.

[0006] To achieve the first object, the present invention discloses a biomass-filled fast-degradable garbage bag, which comprises, by weight:

[0007]

[0008] The raw materials of the biomass rapid degrading agent include biomass straw and bicarbonate.

[0009] In the present invention, by blending biomass straw and bicarbonate, the obtained fast-degradable garbage bag has the characteristics of low cost, excellent mechanical properties, fast degradation rate, etc. Specifically, the biomass straw in the biomass fast-degrading agent contains a large amount of fiber, which can strengthen the polymer matrix and improve the mechanical strength, while bicarbonate can be used in a high humidity environment. On the one hand, bicarbonate (HCO 3 - ) makes the aqueous solution weakly alkaline under hydrolysis, catalyzing the hydrolysis of the degradable polymer matrix; on the other hand, since the straw powder is rich in hydroxyl and carboxyl groups, it is easy to react with bicarbonate to generate water and carbon dioxide, which is conducive to the formation of gas passages in the degradable polymer matrix and leaving micropores, promoting the water absorption, expansion and breakage of the biomass straw, and then causing the overall disintegration of the film bag to achieve the purpose of rapid degradation.

[0010] Furthermore, the weight ratio of the biomass straw and bicarbonate is 100:1-10; illustratively, the weight ratio of the biomass straw and bicarbonate can be 100:1, 100:2, 100:3, 100:4, 100:5, 100:6, 100:7, 100:8, 100:9, 100:10, etc.

[0011] Furthermore, the biomass straw contains fibers and multi-reactive functional groups (such as hydroxyl and carboxyl), including but not limited to ultrafine powder of one or more biomass materials such as reed straw, cotton straw, corn straw, peanut straw, wheat straw, rice straw, tree branches and leaves, and coconut palm materials, with a D90 of 300-800 mesh and a moisture content controlled at 5-30%.

[0012] Furthermore, the bicarbonate is selected from one or more of potassium bicarbonate, calcium bicarbonate, sodium bicarbonate, and magnesium bicarbonate.

[0013] Furthermore, the degradable polymer includes but is not limited to one or more of polybutylene adipate-terephthalate (PBAT), polybutylene succinate (PBS), polybutylene succinate-adipate (PBSA), polyvinyl alcohol (PVA), polylactic acid (PLA), polyglycolic acid (PGA), and polycaprolactone (PCL).

[0014] Furthermore, the rapid degradation aid is selected from one or more of calcium carbonate, calcium oxide, calcium hydroxide, sepiolite, and diatomaceous earth.

[0015] Furthermore, the surface modifier includes, but is not limited to, one or more of oleamide, erucamide, calcium stearate, zinc stearate, stearic acid amide, and N,N'-ethylenebisstearamide.

[0016] Furthermore, the biomass rapid degradation agent is prepared according to the following steps:

[0017] The biomass straw and bicarbonate are mixed evenly according to a certain proportion to obtain a biomass rapid degradation agent reaction raw material;

[0018] Under stirring, the raw materials of the biomass rapid degradation agent reaction are heated to 35-65°C, the stirrer is closed, and the reaction is stirred for 2-5 hours, then the temperature is raised to 85-90°C, the top cover of the stirrer is opened, and stirring is continued under heating to evaporate part of the water vapor. When the water content of the material in the stirrer reaches 5-10%, the heating and stirring are stopped, and the biomass rapid degradation agent is obtained after natural cooling.

[0019] Furthermore, the tensile strength of the fast-degradable garbage bag is greater than 20 MPa, the elongation at break is greater than 250%, and in a high humidity environment with a humidity of more than 85 RH%, it disintegrates within 7 days and is completely composted and degraded within 90 days, with a degradation rate of more than 90%.

[0020] In order to achieve the second objective, the present invention discloses a method for preparing the above-mentioned fast-degradable garbage bag, comprising the following steps:

[0021] S1: Add 100 parts by weight of a degradable polymer, 5-20 parts by weight of a biomass rapid degrader, 1-5 parts by weight of a rapid degradation aid, and 1-2 parts by weight of a surface modifier into a stirrer, mix at room temperature for 15-20 minutes, then heat to 90-120° C. and continue mixing for 25-30 minutes to obtain a premix;

[0022] S2: adding the premix to a twin-screw extruder, and performing melt extrusion at a screw speed of 50-95 rpm and 125-160° C. to obtain a special material for biomass rapid degradation film bags;

[0023] S3: Using a film blowing machine to blow film of the biomass fast-degradable film bag special material, at a screw speed of 15-30rpm and a film blowing temperature of 155-180°C, to prepare a fast-degradable garbage bag.

[0024] Furthermore, in step S2, when the twin-screw extruder is running, the screw speed is 75-85 rpm and the melt extrusion temperature is 140-155°C.

[0025] Furthermore, in step S3, when the film blowing machine is running, the screw speed is 20-25 rpm and the film blowing temperature is 165-175°C.

[0026] The beneficial effects of the present invention are as follows:

[0027] The invention discloses a fast-degradable garbage bag, which has low cost and excellent mechanical properties. The tensile strength is greater than 20MPa, the elongation at break is greater than 250%, and when placed in a high-humidity environment (such as a landfill) with a humidity of more than 85RH%, the bag can be disintegrated within 7 days and completely composted and degraded within 90 days, with a degradation rate of more than 90%, thereby achieving the purpose of fast degradation.

[0028] The fast-degradable garbage bag provided by the present invention also contains 5-20 parts of a biomass fast-degrading agent, wherein the biomass fast-degrading agent includes biomass straw and bicarbonate, wherein the biomass straw contains a large amount of fiber, which can strengthen the polymer matrix and improve the mechanical strength; the bicarbonate can be hydrolyzed in a high-humidity environment to make the aqueous solution weakly alkaline, catalyze the hydrolysis of the degradable polymer matrix, and can also react with the biomass straw to generate water and carbon dioxide, thereby facilitating the formation of gas passages in the degradable polymer matrix and leaving micropores, promoting the water absorption, expansion and breakage of the biomass straw, and then causing the film bag to disintegrate as a whole, thereby achieving the purpose of fast degradation. DETAILED DESCRIPTION

[0029] In order to explain the present invention more clearly, the present invention is further described below in conjunction with preferred embodiments. It should be understood by those skilled in the art that the following specific description is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0030] Unless otherwise specified, the raw materials used in the present invention can be obtained commercially. Any range recorded in the present invention includes the end value and any numerical value between the end values ​​and any sub-range formed by the end value or any numerical value between the end values.

[0031] Example 1

[0032] The fast-degradable garbage bag is composed of the following components by weight:

[0033]

[0034] The raw materials of the biomass rapid degrader are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:10;

[0035] The fast-degradable garbage bag is prepared according to the following steps:

[0036] S1: mixing reed stalk powder and bicarbonate in a weight ratio of 100:10 to obtain a biomass rapid degradation agent reaction raw material;

[0037] S2: Heat the obtained biomass rapid degradation agent reaction raw material to 50°C under stirring, close the stirrer, stir and react for 5 hours, then raise the temperature to 90°C, open the stirrer cover, continue stirring under heating to evaporate part of the water vapor, and stop heating and stirring when the water content of the material in the stirrer reaches 8%, and cool naturally to obtain the biomass rapid degradation agent;

[0038] S3: 100 parts by weight of PBAT, 10 parts by weight of a biomass rapid degrader, 3 parts by weight of calcium oxide, and 2 parts by weight of oleamide are added to a stirrer, first mixed at room temperature at a speed of 130 rpm for 20 min, then heated to 120° C., and continued to mix at a speed of 650 rpm for 30 min to obtain a premix;

[0039] S4: adding the premix to a twin-screw extruder, and performing melt extrusion at a screw speed of 95 rpm and a temperature of 160° C. to obtain a special material for biomass rapid degradation film bags;

[0040] S5: Using a film blowing machine to blow film of the special material for biomass fast-degradable film bags, at a screw speed of 30 rpm and a film blowing temperature of 180° C., a biomass fast-degradable garbage bag is prepared.

[0041] Example 2

[0042] The fast-degradable garbage bag is composed of the following components by weight:

[0043]

[0044] The raw materials of the biomass rapid degrading agent are composed of tree branch and leaf powder and sodium bicarbonate in a weight ratio of 100:10; the preparation process of the rapid degradable garbage bag is the same as that in Example 1.

[0045] Example 3

[0046] The fast-degradable garbage bag is composed of the following components by weight:

[0047]

[0048] The raw materials of the biomass rapid degrading agent are composed of reed stalk powder and magnesium bicarbonate in a weight ratio of 100:10; the preparation process of the rapid degradable garbage bag is the same as that in Example 1.

[0049] Example 4

[0050] The fast-degradable garbage bag is composed of the following components by weight:

[0051]

[0052] The raw materials of the biomass rapid degrading agent are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:10; the preparation process of the rapid degradable garbage bag is the same as that in Example 1.

[0053] Example 5

[0054] The fast-degradable garbage bag is composed of the following components by weight:

[0055]

[0056] The raw materials of the biomass rapid degrading agent are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:10; Comparative Example 1

[0057] The fast-degradable garbage bag is composed of the following components by weight:

[0058]

[0059] Among them, the raw material of the biomass rapid degrader is reed stalk powder.

[0060] The preparation process of the fast-degradable garbage bag is the same as that in Example 1.

[0061] Comparative Example 2

[0062] The fast-degradable garbage bag is composed of the following components by weight:

[0063]

[0064] Among them, the raw material of the biomass rapid degrader is sodium bicarbonate.

[0065] The preparation process of the fast-degradable garbage bag is the same as that in Example 1.

[0066] Comparative Example 3

[0067] The fast-degradable garbage bag is composed of the following components by weight:

[0068]

[0069] The raw materials of the biomass rapid degrader are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:20;

[0070] The preparation process of the fast-degradable garbage bag is the same as that in Example 1.

[0071] Comparative Example 4

[0072] The fast-degradable garbage bag is composed of the following components by weight:

[0073]

[0074] The raw materials of the biomass rapid degrader are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:10;

[0075] The fast-degradable garbage bag is prepared according to the following steps:

[0076] S1: mixing reed stalk powder and bicarbonate in a weight ratio of 100:10 to obtain a biomass rapid degradation agent reaction raw material;

[0077] S2: Heat the obtained biomass rapid degradation agent reaction raw material to 50°C under stirring, close the stirrer, stir and react for 5 hours, then raise the temperature to 90°C, open the stirrer cover, continue stirring under heating to evaporate part of the water vapor, and stop heating and stirring when the water content of the material in the stirrer reaches 4%, and cool naturally to obtain the biomass rapid degradation agent;

[0078] S3: 100 parts by weight of PBAT, 10 parts by weight of a biomass rapid degrader, 3 parts by weight of calcium oxide, and 2 parts by weight of oleamide are added to a stirrer, first mixed at room temperature at a speed of 130 rpm for 20 min, then heated to 120° C., and continued to mix at a speed of 650 rpm for 30 min to obtain a premix;

[0079] S4: adding the premix to a twin-screw extruder, and performing melt extrusion at a screw speed of 95 rpm and a temperature of 160° C. to obtain a special material for biomass rapid degradation film bags;

[0080] S5: Using a film blowing machine to blow film of the special material for biomass fast-degradable film bags, at a screw speed of 30 rpm and a film blowing temperature of 180° C., a biomass fast-degradable garbage bag is prepared.

[0081] Comparative Example 5

[0082] The fast-degradable garbage bag is composed of the following components by weight:

[0083]

[0084] The raw materials of the biomass rapid degrader are composed of reed stalk powder and sodium bicarbonate in a weight ratio of 100:10;

[0085] The fast-degradable garbage bag is prepared according to the following steps:

[0086] S1: mixing reed stalk powder and bicarbonate in a weight ratio of 100:10 to obtain a biomass rapid degradation agent reaction raw material;

[0087] S2: Heat the obtained biomass rapid degradation agent reaction raw material to 50°C under stirring, close the stirrer, stir and react for 5 hours, then raise the temperature to 90°C, open the stirrer cover, continue stirring under heating to evaporate part of the water vapor, and stop heating and stirring when the water content of the material in the stirrer reaches 11%, and cool naturally to obtain the biomass rapid degradation agent;

[0088] S3: 100 parts by weight of PBAT, 10 parts by weight of a biomass rapid degrader, 3 parts by weight of calcium oxide, and 2 parts by weight of oleamide are added to a stirrer, first mixed at room temperature at a speed of 130 rpm for 20 min, then heated to 120° C., and continued to mix at a speed of 650 rpm for 30 min to obtain a premix;

[0089] S4: adding the premix to a twin-screw extruder, and performing melt extrusion at a screw speed of 95 rpm and a temperature of 160° C. to obtain a special material for biomass rapid degradation film bags;

[0090] S5: Using a film blowing machine to blow film of the special material for biomass fast-degradable film bags, at a screw speed of 30 rpm and a film blowing temperature of 180° C., a biomass fast-degradable garbage bag is prepared.

[0091] The performance tests were carried out on the fast-degradable garbage bags prepared in Examples 1-5 of the present invention and Comparative Examples 1-5, wherein the mechanical properties (tensile strength and elongation at break) of the samples were tested according to the standard GB / T 1040.2 2006, the time for the composting degradation rate of the samples to reach 90% was tested according to the standard GB / T19277.1-2011, and the disintegration time refers to the time for the test sample to disintegrate into fragments of which more than 10% can pass through a 22 mm sieve in a high humidity environment.

[0092] Table 1 shows the test results of Examples 1-5 of the present invention and Comparative Examples 1-5: The parameters of the biomass fast-degradable garbage bags of Examples 1-5 all meet the following requirements: in mechanical properties, tensile strength>20MPa, elongation at break>250%; in degradation properties, they disintegrate within 7 days, and the composting degradation rate reaches 90% within 90 days.

[0093] In Comparative Example 1, since there is no sodium bicarbonate in the biomass rapid degrading agent, the degradation rate of the prepared biomass rapid degradable garbage bag is significantly slowed down. In Comparative Example 2, since there is no reed stalk powder in the biomass rapid degrading agent, the prepared biomass rapid degradable garbage bag not only has a decreased elongation at break, but also has a significantly slowed degradation rate. In Comparative Example 3, due to the increase in the proportion of sodium bicarbonate in the biomass rapid degrading agent, the prepared biomass rapid degradable garbage bag degrades rapidly but does not have the mechanical properties required for use. Comparative Examples 4 and 5 are respectively found when preparing biomass rapid degrading agents that the moisture content of the material should be neither too high nor too low. Too low a moisture content is not conducive to accelerated degradation, while too high a moisture content will cause the mechanical properties of the biomass rapid degradable garbage bag to decrease.

[0094] Table 1 Properties of biomass fast-degradable garbage bags

[0095]

[0096]

[0097] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A biomass-filled fast-degradable garbage bag, characterized in that: By weight, including The raw materials of the biomass rapid degrading agent include biomass straw and bicarbonate.

2. The fast-degradable garbage bag according to claim 1, characterized in that: The weight ratio of the biomass straw to bicarbonate is 100:1-10.

3. The fast-degradable garbage bag according to claim 1, characterized in that: The biomass straw is selected from one or more ultrafine powders of reed straw, cotton straw, corn straw, peanut straw, wheat straw, rice straw, tree branches and leaves, and coconut palm materials, with a D90 of 300-800 mesh and a moisture content of 5-30%; The bicarbonate is selected from one or more of potassium bicarbonate, calcium bicarbonate, sodium bicarbonate and magnesium bicarbonate.

4. The fast-degradable garbage bag according to claim 1, characterized in that: The degradable polymer is selected from one or more of polybutylene adipate-terephthalate, polybutylene succinate, polybutylene succinate-adipate, polyvinyl alcohol, polylactic acid, polyglycolic acid, and polycaprolactone.

5. The fast-degradable garbage bag according to claim 1, characterized in that: The rapid degradation aid is selected from one or more of calcium carbonate, calcium oxide, calcium hydroxide, sepiolite and diatomaceous earth.

6. The fast-degradable garbage bag according to claim 1, characterized in that: The surface modifier is selected from one or more of oleamide, erucamide, calcium stearate, zinc stearate, stearic acid amide, and N,N'-ethylenebisstearamide.

7. The fast-degradable garbage bag according to claim 1, characterized in that: The biomass rapid degradation agent is prepared according to the following steps: The biomass straw and bicarbonate are mixed evenly according to a certain proportion to obtain a biomass rapid degradation agent reaction raw material; Under stirring, the raw materials of the biomass rapid degradation agent reaction are heated to 35-65°C, the stirrer is closed, and the reaction is stirred for 2-5 hours, then the temperature is raised to 85-90°C, the top cover of the stirrer is opened, and stirring is continued under heating to evaporate part of the water vapor. When the water content of the material in the stirrer reaches 5-10%, the heating and stirring are stopped, and the biomass rapid degradation agent is obtained after natural cooling.

8. The fast-degradable garbage bag according to claim 1, characterized in that: The rapid degradable garbage bag has a tensile strength of more than 20 MPa and an elongation at break of more than 250%. In a high humidity environment with a humidity of more than 85 RH%, the bag disintegrates within 7 days and is completely composted and degraded within 90 days, with a degradation rate of more than 90%.

9. The method for preparing a fast-degradable garbage bag according to any one of claims 1 to 8, characterized in that: The steps include: S1: Add 100 parts by weight of a degradable polymer, 5-20 parts by weight of a biomass rapid degrader, 1-5 parts by weight of a rapid degradation aid, and 1-2 parts by weight of a surface modifier into a stirrer, mix at room temperature for 15-20 minutes, then heat to 90-120° C. and continue mixing for 25-30 minutes to obtain a premix; S2: adding the premix to a twin-screw extruder, and performing melt extrusion at a screw speed of 50-95 rpm and 125-160° C. to obtain a special material for biomass rapid degradation film bags; S3: Using a film blowing machine to blow film of the biomass fast-degradable film bag special material, at a screw speed of 15-30rpm and a film blowing temperature of 155-180°C, to prepare a fast-degradable garbage bag.

10. The preparation method according to claim 9, characterized in that: In step S2, when the twin-screw extruder is running, the screw speed is 75-85 rpm and the melt extrusion temperature is 140-155° C.; In step S3, when the film blowing machine is running, the screw speed is 20-25 rpm and the film blowing temperature is 165-175°C.

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