Moso bamboo-based degradable material and preparation process thereof

Abstract

The invention discloses a moso bamboo-based degradable material and a preparation process thereof, and relates to the technical field of degradable materials. The plastic is prepared from the following raw materials in parts by weight: 35-45 parts of moso bamboo powder, 20-25 parts of polylactic acid, 20-25 parts of PBAT, 5-10 parts of a compatilizer and 5-10 parts of PBS. According to the invention, moso bamboos are processed into nanoscale superfine bamboo powder through a physical processing technology, after the superfine bamboo powder is added, the requirements of degradable plastics are met, and the bamboo powder is used in the degradable plastic industry and can replace part of resin, so that the cost of degradable plastic products is greatly reduced; the bamboo powder is subjected to alkali treatment modification, colloid on the surface of the bamboo powder can be well removed, the surface polarity of the bamboo powder is reduced, the compatibility between the bamboo powder and polylactic acid is improved, and therefore the crystallinity and the mechanical property of the material are improved; by adding the maleic anhydride grafted compatilizer, the compatibility between the bamboo powder and the polylactic acid is further improved, so that the performance of the material is improved, and meanwhile, the characteristic that the material can be completely biodegraded is ensured.

Description

Technical Field

[0001] This invention relates to the field of biodegradable materials technology, specifically to bamboo-based biodegradable materials and their preparation process. Background Technology

[0002] Plastics are widely used in production and daily life, serving as an essential basic material. However, improper production, use of plastic products, and improper recycling and disposal of plastic waste can lead to resource and energy waste and environmental pollution. Finding alternatives to plastics is an effective way to reduce plastic use, mitigate plastic pollution, and solve the problem at its source. Bamboo, as a green, low-carbon, and biodegradable biomass material, has significant advantages and plays a prominent role in reducing plastic pollution and replacing plastic products.

[0003] my country boasts the world's richest bamboo resources, with a current national bamboo forest area of ​​7.01 million hectares. A single bamboo stalk matures in 3 to 5 years, while typical fast-growing timber forests take 10 to 15 years. Furthermore, bamboo can be successfully planted from scratch and harvested annually; with proper protection, it can be used sustainably. As a green, low-carbon, and biodegradable biomass material, bamboo can directly replace some non-biodegradable plastic products in packaging, building materials, and other fields. "Replacing plastic with bamboo" will increase the proportion of green bamboo products used and reduce plastic pollution.

[0004] However, current bamboo products are costly and difficult to promote due to the complexity of their processing and raw materials. Furthermore, the shelf life and service life of bamboo products are not ideal due to their unique characteristics. Therefore, we propose bamboo-based biodegradable materials and their preparation process to address the aforementioned problems.

[0005] The information disclosed above in this background section is only for enhancing the understanding of the background section of this invention, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0006] The purpose of this invention is to provide bamboo-based biodegradable materials and their preparation process to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a bamboo-based biodegradable material, which, by weight, is composed of the following raw materials: 35-45 parts bamboo powder, 20-25 parts polylactic acid, 20-25 parts PBAT, 5-10 parts compatibilizer, and 5-10 parts PBS.

[0008] Preferably, the compatibilizer is a maleic anhydride grafted compatibilizer.

[0009] The preparation process of bamboo-based biodegradable materials includes the following steps:

[0010] Step 1: Pre-treatment of moso bamboo:

[0011] Step 1.1: Pre-treat the bamboo using a pulverizing device to obtain a bamboo powder mixture;

[0012] Step 1.2: The bamboo powder mixture is coarsely processed and pulverized to obtain coarse bamboo powder;

[0013] Step 1.3: Further process the coarse bamboo powder to obtain fine bamboo powder;

[0014] Step 1.4: Further process the fine bamboo powder to obtain nano-sized bamboo powder, and after thorough drying, seal and store it.

[0015] Step 2, Alkali Treatment and Modification of Bamboo Powder: The dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10, mixed evenly using an ultrasonic disperser, and subjected to a high-temperature water bath reaction. Then it is filtered out and washed with ultrapure water 3-5 times until neutral. Finally, it is placed in a drying oven to dry to constant weight.

[0016] Step 3, Mixing: The modified bamboo powder, polylactic acid, PBAT, maleic anhydride graft compatibilizer and PBS are put into a high-speed mixer and mixed to obtain a blend. After the blend is cooled, it is melt-kneaded.

[0017] Step 4, Crushing and Granulation: The material obtained from melt mixing is crushed into granules using a crusher;

[0018] Step 5: Mold forming: The material particles are placed in the mold and processed into shape according to production needs to obtain biodegradable materials.

[0019] Preferably, in step 1.1, the pretreatment is a mixture of bamboo powder with a particle size of 1-5 mm.

[0020] Preferably, in step 1.2, a high-efficiency pulverizer is used to process the bamboo into coarse bamboo powder of 20-40 mesh.

[0021] Preferably, in step 1.3, the bamboo powder is processed into 200-500 mesh using an ultrafine powder processing and pulverizing equipment.

[0022] Preferably, in step 1.4, the bamboo powder is processed into 800-2000 mesh nano-sized bamboo powder using an ultra-fine powder processing pulverizer or a bamboo powder air jet mill.

[0023] Preferably, in step 1.4, the bamboo powder is placed in a drying oven and dried at 70℃-80℃ for 24h-36h.

[0024] Preferably, in step 2, the high-temperature water bath reaction temperature is 70℃-80℃, the time is 3h-5h, and finally it is placed in a drying oven at 60℃-70℃ for 24h-48h.

[0025] Preferably, in step 3, the melt mixing time is 10h-18h.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] (1) This invention uses physical processing technology to process moso bamboo into nano-level ultrafine bamboo powder. After the ultrafine bamboo powder is added, it meets the requirements of biodegradable plastics and can be used in the biodegradable plastics industry. It can replace part of the resin and significantly reduce the cost of biodegradable plastic products.

[0028] (2) By modifying bamboo powder with alkali treatment, the present invention can effectively remove the colloid on the surface of bamboo powder, reduce the surface polarity of bamboo powder, improve the compatibility between bamboo powder and polylactic acid, thereby improving the crystallinity and mechanical properties of the material.

[0029] (3) By adding maleic anhydride graft compatibilizer, the compatibility between bamboo powder and polylactic acid is further improved, thereby improving the performance of the material and ensuring the material's complete biodegradability.

[0030] The above overview is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features of the invention will become readily apparent from the accompanying drawings and the following detailed description. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the preparation process of the present invention. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1 The biodegradable material based on moso bamboo is composed of the following raw materials by weight: 35-45 parts moso bamboo powder, 20-25 parts polylactic acid, 20-25 parts PBAT, 5-10 parts maleic anhydride graft compatibilizer, and 5-10 parts PBS.

[0034] The preparation process of bamboo-based biodegradable materials includes the following steps:

[0035] Step 1: Pre-treatment of moso bamboo:

[0036] Step 1.1: Pre-treat the bamboo using a pulverizing device to obtain a bamboo powder mixture with a particle size of 1-5 mm;

[0037] Step 1.2: The bamboo powder mixture is coarsely pulverized using a high-efficiency pulverizer to obtain coarse bamboo powder of 20-40 mesh.

[0038] Step 1.3: The coarse bamboo powder is further processed using an ultrafine powder processing and pulverizing equipment to obtain fine bamboo powder of 200-500 mesh;

[0039] Step 1.4: Further process the fine bamboo powder using a fine bamboo powder ultrafine powder processing pulverizer or a bamboo powder air jet mill to obtain 800-2000 mesh nano-grade ultrafine bamboo powder. Place it in a drying oven at 70℃-80℃ for 24-36 hours and then seal it for storage.

[0040] Step 2, Alkali Treatment and Modification of Bamboo Powder: The dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10. The mixture is then stirred evenly using an ultrasonic disperser and reacted in a high-temperature water bath at 70℃-80℃ for 3-5 hours. After that, it is filtered out and washed with ultrapure water 3-5 times until neutral. Finally, it is placed in a drying oven at 60℃-70℃ for 24-48 hours until constant weight is achieved.

[0041] Step 3, Mixing: Put the modified bamboo powder, polylactic acid, PBAT, maleic anhydride graft compatibilizer and PBS into a high-speed mixer and mix them together to obtain a blend. After the blend cools down, melt-mix it for 10-18 hours.

[0042] Step 4, Crushing and Granulation: The material obtained from melt mixing is crushed into granules using a crusher;

[0043] Step 5: Mold forming: The material particles are placed in the mold and processed into shape according to production needs to obtain biodegradable materials.

[0044] Example 1

[0045] Prepare the following raw materials in parts by weight: 35 parts bamboo powder, 25 parts polylactic acid, 25 parts PBAT, 7.5 parts maleic anhydride graft compatibilizer, and 7.5 parts PBS.

[0046] Step 1: Pre-treatment of moso bamboo:

[0047] Step 1.1: Pre-treat the bamboo using a pulverizing device to obtain a bamboo powder mixture with a particle size of 1-5 mm;

[0048] Step 1.2: The bamboo powder mixture is coarsely pulverized using a high-efficiency pulverizer to obtain coarse bamboo powder of 20-40 mesh.

[0049] Step 1.3: The coarse bamboo powder is further processed using an ultrafine powder processing and pulverizing equipment to obtain fine bamboo powder of 200-500 mesh;

[0050] Step 1.4: Further process the fine bamboo powder using a fine bamboo powder ultrafine powder processing pulverizer or a bamboo powder air jet mill to obtain 800-2000 mesh nano-grade ultrafine bamboo powder. Place it in a drying oven at 70℃-80℃ for 24-36 hours and then seal it for storage.

[0051] Step 2, Alkali Treatment and Modification of Bamboo Powder: The dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10. The mixture is then stirred evenly using an ultrasonic disperser and reacted in a high-temperature water bath at 70℃-80℃ for 3-5 hours. After that, it is filtered out and washed with ultrapure water 3-5 times until neutral. Finally, it is placed in a drying oven at 60℃-70℃ for 24-48 hours until constant weight is achieved.

[0052] Step 3, Mixing: Put the modified bamboo powder, polylactic acid, PBAT, maleic anhydride graft compatibilizer and PBS into a high-speed mixer and mix them together to obtain a blend. After the blend cools down, melt-mix it for 10-18 hours.

[0053] Step 4, Crushing and Granulation: The material obtained from melt mixing is crushed into granules using a crusher;

[0054] Step 5: Mold forming: The material particles are placed in the mold and processed into shape according to production needs to obtain biodegradable materials.

[0055] Example 2

[0056] Prepare the following raw materials in parts by weight: 40 parts bamboo powder, 2 parts polylactic acid, 25 parts PBAT, 7.5 parts maleic anhydride graft compatibilizer, and 7.5 parts PBS.

[0057] Step 1: Pre-treatment of moso bamboo:

[0058] Step 1.1: Pre-treat the bamboo using a pulverizing device to obtain a bamboo powder mixture with a particle size of 1-5 mm;

[0059] Step 1.2: The bamboo powder mixture is coarsely pulverized using a high-efficiency pulverizer to obtain coarse bamboo powder of 20-40 mesh.

[0060] Step 1.3: The coarse bamboo powder is further processed using an ultrafine powder processing and pulverizing equipment to obtain fine bamboo powder of 200-500 mesh;

[0061] Step 1.4: Further process the fine bamboo powder using a fine bamboo powder ultrafine powder processing pulverizer or a bamboo powder air jet mill to obtain 800-2000 mesh nano-grade ultrafine bamboo powder. Place it in a drying oven at 70℃-80℃ for 24-36 hours and then seal it for storage.

[0062] Step 2, Alkali Treatment and Modification of Bamboo Powder: The dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10. The mixture is then stirred evenly using an ultrasonic disperser and reacted in a high-temperature water bath at 70℃-80℃ for 3-5 hours. After that, it is filtered out and washed with ultrapure water 3-5 times until neutral. Finally, it is placed in a drying oven at 60℃-70℃ for 24-48 hours until constant weight is achieved.

[0063] Step 3, Mixing: Put the modified bamboo powder, polylactic acid, PBAT, maleic anhydride graft compatibilizer and PBS into a high-speed mixer and mix them together to obtain a blend. After the blend cools down, melt-mix it for 10-18 hours.

[0064] Step 4, Crushing and Granulation: The material obtained from melt mixing is crushed into granules using a crusher;

[0065] Step 5: Mold forming: The material particles are placed in the mold and processed into shape according to production needs to obtain biodegradable materials.

[0066] Example 3

[0067] Prepare the following raw materials in parts by weight: 45 parts bamboo powder, 20 parts polylactic acid, 20 parts PBAT, 7.5 parts maleic anhydride graft compatibilizer, and 7.5 parts PBS.

[0068] Step 1: Pre-treatment of moso bamboo:

[0069] Step 1.1: Pre-treat the bamboo using a pulverizing device to obtain a bamboo powder mixture with a particle size of 1-5 mm;

[0070] Step 1.2: The bamboo powder mixture is coarsely pulverized using a high-efficiency pulverizer to obtain coarse bamboo powder of 20-40 mesh.

[0071] Step 1.3: The coarse bamboo powder is further processed using an ultrafine powder processing and pulverizing equipment to obtain fine bamboo powder of 200-500 mesh;

[0072] Step 1.4: Further process the fine bamboo powder using a fine bamboo powder ultrafine powder processing pulverizer or a bamboo powder air jet mill to obtain 800-2000 mesh nano-grade ultrafine bamboo powder. Place it in a drying oven at 70℃-80℃ for 24-36 hours and then seal it for storage.

[0073] Step 2, Alkali Treatment and Modification of Bamboo Powder: The dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10. The mixture is then stirred evenly using an ultrasonic disperser and reacted in a high-temperature water bath at 70℃-80℃ for 3-5 hours. After that, it is filtered out and washed with ultrapure water 3-5 times until neutral. Finally, it is placed in a drying oven at 60℃-70℃ for 24-48 hours until constant weight is achieved.

[0074] Step 3, Mixing: Put the modified bamboo powder, polylactic acid, PBAT, maleic anhydride graft compatibilizer and PBS into a high-speed mixer and mix them together to obtain a blend. After the blend cools down, melt-mix it for 10-18 hours.

[0075] Step 4, Crushing and Granulation: The material obtained from melt mixing is crushed into granules using a crusher;

[0076] Step 5: Mold forming: The material particles are placed in the mold and processed into shape according to production needs to obtain biodegradable materials.

[0077] Comparative Example 1

[0078] The only difference between Comparative Example 1 and Example 1 is that Comparative Example 1 omits the bamboo powder alkali treatment modification step and directly uses unmodified bamboo powder.

[0079] Comparative Example 2

[0080] The only difference between Comparative Example 2 and Example 2 is that Comparative Example 2 omits the bamboo powder alkali treatment modification step and directly uses unmodified bamboo powder.

[0081] Comparative Example 3

[0082] The only difference between Comparative Example 3 and Example 3 is that Comparative Example 3 omits the bamboo powder alkali treatment modification step and directly uses unmodified bamboo powder.

[0083] Comparative Example 4

[0084] The only difference between Comparative Example 4 and Example 1 is that the raw materials of Comparative Example 4 do not include maleic anhydride graft compatibilizer.

[0085] Comparative Example 5

[0086] The only difference between Comparative Example 5 and Example 2 is that the raw materials of Comparative Example 5 do not include maleic anhydride graft compatibilizer.

[0087] Comparative Example 6

[0088] The only difference between Comparative Example 6 and Example 3 is that the raw materials of Comparative Example 6 do not include maleic anhydride graft compatibilizer.

[0089] Samples were prepared using the raw materials and preparation processes of Examples 1-3 and Comparative Examples 1-6, and mechanical property tests were conducted to verify the following:

[0090] 1. The effect of bamboo powder modification on the properties of biodegradable materials

[0091] project Tensile strength (MPa) Bending strength (MPa) <![CDATA[Impact strength (KJ / m 2 )]]> Example 1 14.71 20.21 10.23 Example 2 14.83 20.54 10.34 Example 3 14.52 20.33 10.15 Comparative Example 1 10.32 16.22 8.12 Comparative Example 2 10.25 16.14 8.09 Comparative Example 3 10.18 16.10 8.16

[0092] As shown above, after alkali treatment modification, the tensile strength, flexural strength, and impact strength of the degradable material reached 14.83 MPa, 20.54 MPa, and 10.34 KJ / m, respectively. 2 Compared to the unmodified bamboo powder biodegradable material, the mechanical properties of the modified bamboo powder were improved by 43.7%, 26.6%, and 27.3%, respectively. Unmodified bamboo powder has a highly polar surface, which is incompatible with non-polar polylactic acid (PLA), resulting in poor mechanical properties of the biodegradable material. However, after alkali treatment, the polarity of the bamboo powder decreased, and the compatibility between bamboo powder and PLA improved, thus enhancing the overall mechanical properties of the biodegradable material.

[0093] 2. Effect of maleic anhydride graft compatibilizer addition on the properties of biodegradable materials

[0094] project Tensile strength (MPa) Bending strength (MPa) <![CDATA[Impact strength (KJ / m 2 )]]> Example 1 14.71 20.21 10.23 Example 2 14.83 20.54 10.34 Example 3 14.52 20.33 10.15 Comparative Example 4 10.95 17.09 7.60 Comparative Example 5 11.03 17.12 7.89 Comparative Example 6 10.88 17.04 7.76

[0095] As shown above, after adding maleic anhydride graft compatibilizer, the tensile strength, flexural strength, and impact strength of the degradable material reached 14.83 MPa, 20.54 MPa, and 10.34 KJ / m, respectively. 2 Compared to the unmodified bamboo powder degradable material, the mechanical properties of the material were improved by 34.4%, 19.9%, and 31.1%, respectively. Maleic anhydride graft compatibilizer acts as a "bridge" between bamboo powder and polylactic acid, significantly improving the bonding between them and thus enhancing the mechanical properties of the degradable material.

[0096] In summary, this invention utilizes physical processing technology to process moso bamboo into nano-scale ultrafine bamboo powder. This ultrafine bamboo powder, once added, meets the requirements for biodegradable plastics and can be used in the biodegradable plastics industry, replacing some resins and significantly reducing the cost of biodegradable plastic products. Furthermore, by modifying the bamboo powder with alkali treatment, this invention effectively removes the colloids on the bamboo powder surface, reduces the surface polarity of the bamboo powder, and improves the compatibility between bamboo powder and polylactic acid, thereby increasing the crystallinity and mechanical properties of the material. Finally, by adding a maleic anhydride graft compatibilizer, this invention further improves the compatibility between bamboo powder and polylactic acid, thereby enhancing the material's performance while ensuring its complete biodegradability.

[0097] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0098] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. Bamboo-based biodegradable materials, It is characterized in that The preparation method is composed of the following raw materials in parts by weight: 35-45 parts of bamboo powder, 20-25 parts of polylactic acid, 20-25 parts of PBAT, 5-10 parts of compatibilizer and 5-10 parts of PBS.

2. The bamboo-based degradable material according to claim 1, Features: The compatibilizer is a maleic anhydride grafted compatibilizer.

3. The preparation process of the bamboo-based degradable material according to any one of claims 1 to 2, It is characterized in that The steps include: Step 1: Bamboo pretreatment: Step 1.1, pre-treating the bamboo by crushing equipment to obtain a bamboo powder mixture; Step 1.2, roughly processing and crushing the bamboo powder mixture to obtain coarse bamboo powder; Step 1.3, further processing the coarse bamboo powder to obtain fine bamboo powder; Step 1.4, further processing the fine bamboo powder to obtain nano-scale ultrafine bamboo powder, and after being fully dried, sealing and storing; Step 2, modification of bamboo powder by alkali treatment: the dried bamboo powder is placed in a 3% sodium hydroxide solution at a solid-liquid ratio of 1:10, mixed evenly using an ultrasonic disperser, and reacted in a high-temperature water bath, then filtered out, washed with ultrapure water for 3-5 times until neutral, and finally placed in a drying oven to dry to constant weight; Step 3, mixing: putting the modified bamboo powder, polylactic acid, PBAT, maleic anhydride grafted compatibilizer and PBS into a high-speed mixer and blending to obtain a blend, and after the blend is cooled, melt-mixing is performed; Step 4, crushing and granulating: crush the melt-mixed material into granules using a crusher; Step 5: Mold forming: Place the material particles in a mold for processing and forming according to production needs to obtain a degradable material.

4. The preparation process of the bamboo-based degradable material according to claim 1, Features: In the step 1.1, the pre-treatment is to prepare a bamboo powder mixture with a particle size of 1-5 mm.

5. The preparation process of the bamboo-based degradable material according to claim 1, Features: In the step 1.2, a high-efficiency crusher is used to process the bamboo powder into 20-40 mesh coarse bamboo powder.

6. The preparation process of the bamboo-based degradable material according to claim 1, Features: In the step 1.3, ultrafine powder processing and crushing equipment is used to process the bamboo powder into fine bamboo powder of 200-500 mesh.

7. The preparation process of the bamboo-based degradable material according to claim 1, Features: In the step 1.4, ultrafine powder processing and pulverizing equipment or bamboo powder air flow mill is used to process the bamboo powder into 800-2000 mesh nano-grade bamboo powder.

8. The process for preparing the bamboo-based degradable material according to claim 1, Features: In the step 1.4, the bamboo powder is placed in a drying oven at 70° C.-80° C. and dried for 24 h-36 h.

9. The process for preparing the bamboo-based degradable material according to claim 1, Features: In the step 2, the high temperature water bath reaction temperature is 70°C-80°C, the reaction time is 3h-5h, and finally the mixture is placed in a drying oven at 60°C-70°C for drying for 24h-48h.

10. The process for preparing the bamboo-based degradable material according to claim 1, Features: In the step 3, the melt mixing time is 10h-18h.

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