Bamboo powder foaming product and preparation method thereof

Abstract

The preparation method comprises the following steps: taking chitosan and bamboo powder, mixing, adding water, uniformly stirring, adding acetic acid while stirring, then adding a cross-linking agent, stirring at a high speed, centrifuging after high-speed stirring, removing supernate, putting the obtained turbid liquid into a container, and molding to obtain a toughening material blank; freeze-drying and crushing the toughening material blank to obtain toughening material powder; the preparation method comprises the following steps: uniformly mixing bamboo powder, starch and toughening material powder, adding a nucleating agent, invertase and an adhesive, uniformly mixing, then adding water, and stirring for 60-120 seconds to pre-expand the toughening material powder and the bamboo powder; adding a foaming agent, and stirring to form a soft bamboo powder dough; the bamboo powder, the starch, the toughening material powder, the nucleating agent, the foaming agent, the adhesive and the water are 55-65 parts by mass of the bamboo powder, 13-15 parts by mass of the starch, 5-8 parts by mass of the toughening material powder, 0.2-0.4 part by mass of the nucleating agent, 2-4 parts by mass of the foaming agent, 1-2 parts by mass of the adhesive and 15-20 parts by mass of the water; and carrying out hot press molding on the bamboo powder dough at 210-220 DEG C to obtain the bamboo powder.

Description

Technical Field

[0001] The invention belongs to the technical field of foaming materials, and particularly relates to a bamboo powder foaming product and a preparation method thereof. Background Art

[0002] The starch content in starch foaming materials is generally high, resulting in high costs. The invention patent with application publication number CN113843949A discloses a waterproof starch foaming packaging material and a production method, comprising 70-90 parts of starch, 5-20 parts of filler, 1-5 parts of foaming agent, and 5-10 parts of processing aid. The starch content in the waterproof starch foaming packaging material is relatively high.

[0003] Bamboo powder is used in combination with starch, and after adding a foaming agent, bamboo powder foam products are formed under high temperature pressing conditions, which can be used as tableware, packaging supplies, etc. The invention patent with application publication number CN105885104A discloses a potato starch bamboo powder composite foam material and its preparation method. The invention patent with application publication number CN113843949A discloses a waterproof starch foam packaging material and its production method. (1) Take 100 parts (by mass) of bamboo powder and 5 parts of 2% sodium oxide aqueous solution and stir them evenly, then keep them warm at 10°C and let them stand for 2 hours for use; (2) Take 5 parts of barley malt and grind them into powder, mix them with 200 parts of water, and then add 5 parts of dry yeast and mix them for use; (3) Take 100 parts of potato starch, mix them with 5 parts of the solution obtained in step (2), and keep them warm at 40°C for 1 hour for use; (4) Prepare one: take 15 parts of bamboo powder treated in step (1), 85 parts of starch treated in step (3), and 2 parts of calcium hydroxide. , 3 parts of aluminum hydroxide, 3 parts of alum, 3 parts of sodium bicarbonate, 5 parts of glycerol, blend in a high-speed mixer for 5 minutes and set aside; Preparation 2: Take 35 parts of bamboo powder treated in step (1), 65 parts of starch treated in step (3), 3 parts of calcium hydroxide, 5 parts of aluminum hydroxide, 5 parts of alum, 5 parts of sodium bicarbonate, 8 parts of glycerol, blend in a high-speed mixer for 10 minutes and set aside; Preparation 3: Take 50 parts of bamboo powder treated in step (1), 50 parts of starch treated in step (3), 6 parts of calcium hydroxide, 8 parts of aluminum hydroxide, 8 parts of alum, 8 parts of sodium bicarbonate, 15 parts of glycerol, blend in a high-speed mixer for 15 minutes and set aside; (5) Extrude the mixed materials into foam through a screw extruder, control the die head temperature to 130°C, the die head pressure to 3MPa, and the screw speed to 70r / min. Bamboo powder foam products are generally fully degradable products, which are required to be biodegradable under natural conditions, such as completely degradable in soil.

[0004] The following problems exist in the production process of existing bamboo powder foam products made of bamboo powder and starch: when the bamboo powder content is high, that is, higher than 30% by mass, the bamboo powder foam products have low toughness and are particularly easy to break. Adding a substance that increases toughness can improve the toughness of the bamboo powder foam products, but the general substance that increases toughness is not easy to biodegrade under natural conditions. Therefore, the existing bamboo powder foam products cannot have both high toughness and easy degradation. Summary of the invention

[0005] The invention aims to provide a bamboo powder foamed product which has good toughness and is easily biodegradable.

[0006] In order to achieve the above purpose, the technical solution adopted by the present invention is:

[0007] A method for preparing a bamboo powder foam product comprises the following steps:

[0008] S1: Take chitosan and bamboo powder, add water and stir evenly, add acetic acid while stirring, then add a cross-linking agent and stir at high speed, centrifuge and remove the supernatant after the high-speed stirring, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder;

[0009] S2: Mix bamboo powder, starch, and toughening material powder evenly, add a nucleating agent, an invertase, and an adhesive, and then add water and stir for 60 to 120 seconds to pre-expand the toughening material powder and the bamboo powder; then add a foaming agent and stir to form a soft bamboo powder mass; the mass proportions of the bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are as follows: 55 to 65 parts of bamboo powder, 13 to 15 parts of starch, 5 to 8 parts of toughening material powder, 0.2 to 0.4 parts of nucleating agent, 2 to 4 parts of foaming agent, 1 to 2 parts of adhesive, and 15 to 20 parts of water;

[0010] S3: hot pressing the bamboo flour dough at 210-220° C. to obtain the bamboo flour dough.

[0011] Furthermore, after the bamboo powder is stirred into a soft dough in step S2, stirring is continued for 10 to 15 minutes at 35 to 40° C. for pre-foaming.

[0012] Furthermore, in step S1, the mass ratio of chitosan to bamboo powder is 1:10-12, the mass ratio of chitosan to water is 1:90-95; and the mass ratio of chitosan to acetic acid is 1:0.05-0.08.

[0013] Furthermore, the cross-linking agent is an aqueous solution of glutaraldehyde, the mass concentration of the aqueous solution of glutaraldehyde is 15-20 mg / mL, and the mass ratio of chitosan to the cross-linking agent is 1:12-15.

[0014] Furthermore, the invertase in step S2 is cellulase, the amount of invertase added is 2-3 mL per kg of bamboo powder, and the enzymatic activity of the cellulase is 3000-5000 U / L.

[0015] Furthermore, the rotation speed of the high-speed stirring in step S1 is 5000-6000 r / min.

[0016] Furthermore, the bamboo powder and toughening material powder are both powders that have passed through a 400-mesh sieve.

[0017] Furthermore, the starch is one or more of cassava starch, corn starch or potato starch.

[0018] Furthermore, the foaming agent is baking powder, the nucleating agent is calcium carbonate, and the binder is polyvinyl alcohol.

[0019] The bamboo powder foam product prepared by the bamboo powder foam product preparation method.

[0020] Beneficial effects of the present invention:

[0021] The preparation method of the bamboo powder foamed product of the present invention comprises the following steps: the toughening material powder formed by chitosan and bamboo powder absorbs water, swells and explodes to form a microporous skeleton structure when encountering water; the bamboo powder also slightly swells when absorbing water and is filled in the microporous skeleton structure together with starch; and then when the starch is foamed and hot-pressed at high temperature, the water evaporates instantly to form a porous structure; the bamboo powder fiber, the toughening material and the starch are cross-linked to form a stable network structure; under the condition of low starch content, the foaming ratio is high, the toughness of the bamboo powder foamed product is improved, the brittleness of the bamboo powder foamed product is reduced, the product can be used normally, and can be completely degraded in a natural environment, and both the use performance and biodegradability of the bamboo powder foamed product are taken into consideration. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a photo of the internal foaming of the foaming material in Example 1;

[0023] Figure 2 This is a photo of the internal foaming of the foaming material in Comparative Example 1;

[0024] Figure 3 This is a photo of the internal foaming of the foaming material in Comparative Example 2;

[0025] Figure 4 This is a photo of the internal foaming of the foam material in Comparative Example 3. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the embodiments of the present invention and the accompanying drawings.

[0027] Example 1

[0028] The preparation method of the bamboo powder foam product of this embodiment comprises the following steps:

[0029] S1: Take 100g chitosan and 1000g bamboo powder, add 9000g water after mixing and stir evenly, add 6g acetic acid while stirring, then add 1300g cross-linking agent and stir at high speed, the speed of high-speed stirring is 5000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 18mg / mL.

[0030] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent, invertase, and adhesive and mix them evenly. Then add water and stir for 120s to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 60kg bamboo powder, 15kg starch, 8kg toughening material powder, 0.4kg nucleating agent, 4kg foaming agent, 1.5kg adhesive, and 18kg water. The invertase is cellulase, and the amount of invertase added is 2mL per kg of bamboo powder. The enzyme activity of cellulase is 3000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate and the binder is polyvinyl alcohol.

[0031] S3: The bamboo flour dough is hot-pressed at 220° C. to obtain the obtained product, and the hot-pressing time is 18 seconds.

[0032] The bamboo powder foam product of this embodiment is prepared by the preparation method of the bamboo powder foam product of this embodiment.

[0033] Example 2

[0034] The preparation method of the bamboo powder foam product of this embodiment comprises the following steps:

[0035] S1: Take 100g chitosan and 1200g bamboo powder, add 9500g water after mixing and stir evenly, add 5g acetic acid while stirring, then add 1500g cross-linking agent and stir at high speed, the speed of high-speed stirring is 5000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 20mg / mL.

[0036] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent, invertase, and adhesive and mix them evenly. Then add water and stir for 60 seconds to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 65kg bamboo powder, 13kg starch, 6kg toughening material powder, 0.2kg nucleating agent, 3kg foaming agent, 2kg adhesive, and 20kg water. The invertase is cellulase, and the amount of invertase added is 3mL per kg of bamboo powder. The enzyme activity of cellulase is 5000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is cassava starch. The nucleating agent is calcium carbonate and the binder is polyvinyl alcohol.

[0037] S3: hot-pressing the bamboo flour dough at 210° C. to obtain the bamboo flour dough, wherein the hot-pressing time is 20 seconds.

[0038] The bamboo powder foam product of this embodiment is prepared by the preparation method of the bamboo powder foam product of this embodiment.

[0039] Example 3

[0040] The preparation method of the bamboo powder foam product of this embodiment comprises the following steps:

[0041] S1: Take 100g chitosan and 1100g bamboo powder, add 9200g water after mixing and stir evenly, add 8g acetic acid while stirring, then add 1200g cross-linking agent and stir at high speed, the speed of high-speed stirring is 6000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 15mg / mL.

[0042] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent, invertase, and adhesive and mix them evenly. Then add water and stir for 120s to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 55kg bamboo powder, 14kg starch, 5kg toughening material powder, 0.3kg nucleating agent, 2kg foaming agent, 1.8kg adhesive, and 20kg water. The invertase is cellulase, and the amount of invertase added is 2mL per kg of bamboo powder. The enzyme activity of cellulase is 4000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate and the binder is polyvinyl alcohol.

[0043] S3: The bamboo flour dough is hot-pressed at 210° C. to obtain the obtained product, and the hot-pressing time is 18 seconds.

[0044] The bamboo powder foam product of this embodiment is prepared by the preparation method of the bamboo powder foam product of this embodiment.

[0045] Example 4

[0046] The preparation method of the bamboo powder foam product of this embodiment comprises the following steps:

[0047] S1: Take 100g chitosan and 1000g bamboo powder, add 9200g water after mixing and stir evenly, add 6g acetic acid while stirring, then add 1300g cross-linking agent and stir at high speed, the speed of high-speed stirring is 6000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 18mg / mL.

[0048] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent, invertase, and adhesive and mix them evenly. Then add water and stir for 120s to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 60kg bamboo powder, 15kg starch, 6kg toughening material powder, 0.2kg nucleating agent, 2kg foaming agent, 1.5kg adhesive, and 15kg water. The invertase is cellulase, and the amount of invertase added is 2mL per kg of bamboo powder. The enzyme activity of cellulase is 4000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is potato starch. The nucleating agent is calcium carbonate and the binder is polyvinyl alcohol.

[0049] S3: hot pressing the bamboo flour dough at 220° C. to obtain the bamboo flour dough, wherein the hot pressing time is 20 seconds.

[0050] The bamboo powder foam product of this embodiment is prepared by the preparation method of the bamboo powder foam product of this embodiment.

[0051] Example 5

[0052] The preparation method of the bamboo powder foam product of this embodiment comprises the following steps:

[0053] S1: Take 100g chitosan and 1200g bamboo powder, add 9200g water after mixing and stir evenly, add 8g acetic acid while stirring, then add 1500g cross-linking agent and stir at high speed, the speed of high-speed stirring is 5000-6000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 12mg / mL.

[0054] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent, invertase, and adhesive and mix them evenly. Then add water and stir for 120s to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 65kg bamboo powder, 14kg starch, 5kg toughening material powder, 0.4kg nucleating agent, 4kg foaming agent, 5kg adhesive, and 18kg water. The invertase is cellulase, and the amount of invertase added is 3mL per kg of bamboo powder. The enzyme activity of cellulase is 3000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate and the binder is polyvinyl alcohol.

[0055] S3: The bamboo flour dough is hot-pressed at 210° C. to obtain the obtained product, and the hot-pressing time is 18 seconds.

[0056] The bamboo powder foam product of this embodiment is prepared by the preparation method of the bamboo powder foam product of this embodiment.

[0057] Comparative Example 1

[0058] The preparation method of the bamboo powder foam product in this comparative example is roughly the same as that in Example 1, except that: in this comparative example, no toughening material powder is added, and starch is used instead of the toughening material powder, that is, the following steps are included:

[0059] S1: Take bamboo powder and starch and mix them evenly, add nucleating agent, invertase and adhesive and mix them evenly, then add water and stir for 120s to pre-expand the bamboo powder, then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12min at 40℃ for pre-foaming. The masses of bamboo powder, starch, nucleating agent, foaming agent, adhesive and water are: 60kg bamboo powder, 23kg starch, 0.4kg nucleating agent, 4kg foaming agent, 1.5kg adhesive and 18kg water respectively. The invertase is cellulase, and the amount of invertase added is 2mL per kg of bamboo powder, and the enzyme activity of cellulase is 3000U / L. Bamboo powder is a powder that passes through a 400 mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate and the adhesive is polyvinyl alcohol.

[0060] S2: The bamboo flour dough is hot-pressed at 220° C. to obtain the obtained product, and the hot-pressing time is 18 s.

[0061] The bamboo powder foamed product of this comparative example is prepared by the preparation method of the bamboo powder foamed product of this comparative example.

[0062] Comparative Example 2

[0063] The preparation method of the bamboo powder foam product in this comparative example is roughly the same as that in Example 1, except that no invertase is added, that is, the method comprises the following steps:

[0064] S1: Take 100g chitosan and 1000g bamboo powder, add 9000g water after mixing and stir evenly, add 6g acetic acid while stirring, then add 1300g cross-linking agent and stir at high speed, the speed of high-speed stirring is 5000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 18mg / mL.

[0065] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly. Add nucleating agent and adhesive and mix them evenly. Then add water and stir for 120s to pre-expand the toughening material powder and bamboo powder. Then add foaming agent and stir into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring for 12 minutes at 40°C for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 60kg bamboo powder, 15kg starch, 8kg toughening material powder, 0.4kg nucleating agent, 4kg foaming agent, 1.5kg adhesive, and 18kg water. Both bamboo powder and toughening material powder are powders that have passed a 400-mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate, and the adhesive is polyvinyl alcohol.

[0066] S3: The bamboo flour dough is hot-pressed at 220° C. to obtain the obtained product, and the hot-pressing time is 18 seconds.

[0067] The bamboo powder foamed product of this comparative example is prepared by the preparation method of the bamboo powder foamed product of this comparative example.

[0068] Comparative Example 3

[0069] The preparation method of the bamboo powder foamed product in this comparative example is roughly the same as that in Example 1, except that no pre-expansion is performed, that is, the method comprises the following steps:

[0070] S1: Take 100g chitosan and 1000g bamboo powder, add 9000g water after mixing and stir evenly, add 6g acetic acid while stirring, then add 1300g cross-linking agent and stir at high speed, the speed of high-speed stirring is 5000r / min. After high-speed stirring, centrifuge to remove the supernatant, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; the cross-linking agent is an aqueous solution of glutaraldehyde, and the mass concentration of the glutaraldehyde aqueous solution is 18mg / mL.

[0071] S2: Take bamboo powder, starch, and toughening material powder and mix them evenly, add nucleating agent, invertase, and adhesive and mix them evenly, then add water and foaming agent and stir them into a soft bamboo powder mass. After stirring into a soft bamboo powder mass, continue stirring at 40°C for 12 minutes for pre-foaming. The masses of bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are: 60kg bamboo powder, 15kg starch, 8kg toughening material powder, 0.4kg nucleating agent, 4kg foaming agent, 1.5kg adhesive, and 18kg water. The invertase is cellulase, and the amount of invertase added is 2mL per kg of bamboo powder. The enzyme activity of cellulase is 3000U / L. Both bamboo powder and toughening material powder are powders that pass through a 400-mesh sieve. The foaming agent is baking powder. The starch is corn starch. The nucleating agent is calcium carbonate, and the adhesive is polyvinyl alcohol.

[0072] S3: The bamboo flour dough is hot-pressed at 220° C. to obtain the obtained product, and the hot-pressing time is 18 seconds.

[0073] The bamboo powder foamed product of this comparative example is prepared by the preparation method of the bamboo powder foamed product of this comparative example.

[0074] The foaming morphologies of the bamboo powder foam products of Example 1 and Comparative Examples 1 to 3 are observed. Figure 1-Figure 4 As shown, from Figure 1 It can be seen that the bubbles of the bamboo powder foam product of Example 1 are uniform in size and relatively dense. The bubbles of the bamboo powder foam product of Comparative Example 1 are relatively large and sparse. The bubbles of the bamboo powder foam product of Comparative Example 2 are uneven, and the bubbles are larger than those of the bamboo powder foam product of Example 1. The bubbles of the bamboo powder foam product of Comparative Example 3 are of different sizes, and the difference between large bubbles and small bubbles is relatively large.

[0075] Test Example 1

[0076] The mechanical properties of the bamboo powder foam products of Example 1 and Comparative Examples 1 to 3 were measured, and the test results are shown in Table 1.

[0077] Table 1 Mechanical properties of bamboo powder foam products of Example 1 and Comparative Examples 1-3

[0078] Bamboo powder foam product samples Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Elongation at break (%) 4.51 3.75 3.56 2.97

[0079] It can be seen from Table 1 that the elongation at break of the sample in Example 1 of the present invention is relatively high, which means that the sample in Example 1 has good toughness and is not easy to break.

[0080] Test Example 2

[0081] The degradation performance of the bamboo powder foam products of Example 1 and Comparative Examples 1 to 3 was measured. The bamboo powder foam products of Example 1 and Comparative Examples 1 to 3 were broken into sample blocks of about 1 cm×1 cm, and buried in the soil to keep the soil moist. The results are shown in Table 2.

[0082] Table 2 Degradability of bamboo powder foam products of Example 1 and Comparative Examples 1-3

[0083]

[0084] As can be seen from Table 2, the bamboo powder foam product of the present invention has good degradation performance and can be completely degraded after being buried for 3 months, indicating that the added toughening material does not affect its decomposition performance.

Claims

1. A method for preparing a bamboo powder foam product, characterized in that: The following steps are involved: S1: Take chitosan and bamboo powder, add water and stir evenly, add acetic acid while stirring, then add a cross-linking agent and stir at high speed, centrifuge and remove the supernatant after the high-speed stirring, place the obtained suspension in a container to form a toughening material embryo, freeze-dry and crush the toughening material embryo to obtain a toughening material powder; S2: Mix bamboo powder, starch, and toughening material powder evenly, add a nucleating agent, an invertase, and an adhesive, and then add water and stir for 60 to 120 seconds to pre-expand the toughening material powder and the bamboo powder; then add a foaming agent and stir to form a soft bamboo powder mass; the mass proportions of the bamboo powder, starch, toughening material powder, nucleating agent, foaming agent, adhesive, and water are as follows: 55 to 65 parts of bamboo powder, 13 to 15 parts of starch, 5 to 8 parts of toughening material powder, 0.2 to 0.4 parts of nucleating agent, 2 to 4 parts of foaming agent, 1 to 2 parts of adhesive, and 15 to 20 parts of water; S3: hot pressing the bamboo flour dough at 210-220° C. to obtain the bamboo flour dough.

2. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: Step S2: After the bamboo powder is stirred into a soft dough, stirring is continued for 10 to 15 minutes at 35 to 40° C. to perform pre-foaming.

3. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: In step S1, the mass ratio of chitosan to bamboo powder is 1:10-12, the mass ratio of chitosan to water is 1:90-95; and the mass ratio of chitosan to acetic acid is 1:0.05-0.

08.

4. The method for preparing the bamboo powder foamed product according to any one of claims 1 to 3, characterized in that: The cross-linking agent is an aqueous solution of glutaraldehyde, the mass concentration of the aqueous solution of glutaraldehyde is 15-20 mg / mL, and the mass ratio of chitosan to the cross-linking agent is 1:12-15.

5. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: The invertase in step S2 is cellulase, the amount of invertase added is 2-3 mL per kg of bamboo powder, and the enzymatic activity of the cellulase is 3000-5000 U / L.

6. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: The rotation speed of the high-speed stirring in step S1 is 5000-6000 r / min.

7. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: The bamboo powder and toughening material powder are both powders that have passed through a 400-mesh sieve.

8. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: The starch is one or more of cassava starch, corn starch or potato starch.

9. The method for preparing the bamboo powder foamed product according to claim 1, characterized in that: The foaming agent is baking powder, the nucleating agent is calcium carbonate, and the binder is polyvinyl alcohol.

10. The bamboo powder foamed product prepared by the method for preparing the bamboo powder foamed product according to claim 1.

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