Thermoplastic starch-based biomass composite material, product and preparation method

Abstract

The invention discloses a thermoplastic starch-based biomass composite material, a product and a preparation method. The thermoplastic starch-based biomass composite material or product comprises 70%-84% of a biomass material, 16%-24% of N-methylmorpholine-N-oxide and 0%-8% of urea. The biodegradable plastic also can contain one or more of an inorganic filler, a biomass derived material and a biodegradable synthetic polymer. The biomass material can be one or more of a starch material, a cellulose material, a protein material and a chitin material. The mass ratio of the N-methylmorpholine-N-oxide to the urea is preferably (3: 1)-(1: 1). The thermoplastic starch-based biomass composite material is prepared by thermoplastic melting, mixing and extruding, and a product is prepared by thermoplastic extrusion or thermoplastic injection molding. The thermoplastic starch-based biomass composite material and the product are completely biodegradable, excellent in mechanical property and low in cost, and the preparation method is simple, convenient and feasible.

Description

Technical Field

[0001] The present invention relates to a completely biodegradable thermoplastic material, product and preparation method thereof, and particularly to a thermoplastic starch-based biomass composite material, product and preparation method thereof, belonging to the field of biodegradable polymer materials and products. Background Art

[0002] In the past few decades, polymer materials have developed rapidly and vigorously. They not only have a wide variety of types, but also have excellent mechanical properties, and the manufacturing process is simple and fast. The finished products are applicable to various fields in the industry. Nowadays, with the accelerating pace of life, the fast food takeaway industry and the online shopping industry have been rising continuously, and the usage of foams, plastic bags, food preservative films and disposable plastic tableware made of polypropylene, polyethylene, polystyrene, etc. has increased sharply. These traditional petroleum-based plastic products are difficult to recycle and reuse due to their non-degradability, resulting in waste management and pollution problems. Therefore, in order to protect the environment, it is necessary to search for natural raw materials in renewable resources for research, so as to replace the traditional petroleum-based plastics consumed in large quantities every year. Starch, as a rich renewable resource in nature, has the characteristics of non-toxicity and low cost. Using other biomass materials such as cellulose materials and protein materials to compound with starch into a thermoplastic and completely biodegradable composite material is the research focus in the field of biodegradable material science. Summary of the Invention

[0003] The purpose of the present invention is to provide a thermoplastic starch-based biomass composite material, product and preparation method thereof that are completely biodegradable, have excellent mechanical properties, and have a simple and easy preparation method.

[0004] The technical solution to achieve the purpose of the present invention is: a thermoplastic starch-based biomass composite material or product, comprising 70% - 84% of biomass material, 16% - 24% of N-methylmorpholine-N-oxide, and 0% - 8% of urea.

[0005] For the thermoplastic starch-based biomass composite material or product of the present invention, the biomass material can be one or more of starch materials, cellulose materials, protein materials, and chitin materials.

[0006] The thermoplastic starch-based biomass composite material or product of the present invention can contain one or more of inorganic fillers, biomass-derived materials, and biodegradable synthetic polymers.

[0007] For the thermoplastic starch-based biomass composite material or product of the present invention, the melting point of the biodegradable synthetic polymer must be ≤ 140 °C.

[0008] For the thermoplastic starch-based biomass composite material or product of the present invention, the mass ratio of N-methylmorpholine-N-oxide to urea is preferably 3:1 - 1:1.

[0009] The thermoplastic starch-based biomass composite material or product of the present invention is formed into a product by thermoplastic extrusion or thermoplastic injection molding.

[0010] A preparation method of a thermoplastic starch-based biomass composite material or product successively includes the following steps:

[0011] (1) Heat and mix starch, urea, and N-methylmorpholine-N-oxide liquid;

[0012] (2) Solid-state mix with a cellulose material, a protein material, or a chitin material;

[0013] (3) Use a screw extruder to melt and mix and extrude to obtain a thermoplastic starch-based biomass composite material;

[0014] (4) Then use an injection molding machine for thermoplastic injection molding to become a thermoplastic starch-based biomass composite product.

[0015] The preparation method of the thermoplastic starch-based biomass composite material or product of the present invention may also be: successively including the following steps:

[0016] (1) Mix starch, urea, and N-methylmorpholine-N-oxide liquid, and use a screw extruder to melt and mix into a thermoplastic starch material;

[0017] (2) Use a screw extruder to melt and mix and extrude the thermoplastic starch material with a cellulose material, a protein material, or a chitin material into biomass thermoplastic material particles;

[0018] (3) Use an injection molding machine to inject the thermoplastic material particles into a thermoplastic starch-based biomass completely biodegradable thermoplastic composite product.

[0019] For the preparation method of the thermoplastic starch-based biomass composite material or product of the present invention, the content of N-methylmorpholine-N-oxide in the N-methylmorpholine-N-oxide liquid ≥ 75%.

[0020] In the preparation method of the thermoplastic starch-based biomass composite material or product of the present invention, the melting and mixing temperature of the screw extruder must ≤ 140°C, and the injection molding temperature of the injection molding machine must ≤ 140°C.

[0021] The thermoplastic starch-based biomass composite material, product, and preparation method of the present invention have the following remarkable advantages: (1) The N-methylmorpholine-N-oxide used in the present invention is environmentally friendly, and the thermoplastic starch-based biomass composite material and product of the present invention are completely biodegradable, have excellent mechanical properties, and are low in cost; (2) The preparation method of the thermoplastic starch-based biomass composite material and product of the present invention is simple, and a product can be obtained through a two-step method of extrusion and injection molding, and the molding method is simple and easy to implement. Specific Embodiments

[0022] The thermoplastic starch-based biomass composite material or product of the present invention comprises 70% - 84% of biomass material, 16% - 24% of N-methylmorpholine-N-oxide, and 0% - 8% of urea.

[0023] For the thermoplastic starch-based biomass composite material or product of the present invention, the biomass material can be one or more of starch materials, cellulose materials, protein materials, and chitin materials. The starch material in the present invention refers to plant materials with starch as the main organic component, which can be one or more of rice, wheat, corn, sorghum, and tubers. Tubers can be potatoes, sweet potatoes, cassava, etc. The cellulose material in the present invention refers to plant materials with cellulose as the main organic component, such as cotton, wood powder, bamboo powder, bagasse, reed, corn stalk, grass, rice husk, walnut shell, etc. The protein material in the present invention refers to plant materials with protein as the main organic component, such as beans (soybeans, peas, mung beans, etc.), soybean dregs, etc. The chitin material in the present invention refers to animal shells with chitin as the main organic component, such as shrimp shells, shellfish, etc. The term "one or more" as used in this text means two or more.

[0024] The thermoplastic starch-based biomass composite material or product of the present invention can contain one or more of inorganic fillers, biomass-derived materials, and biodegradable synthetic polymers. Inorganic fillers such as calcium carbonate, talcum powder, montmorillonite, etc., and the mass content in the entire biomass thermoplastic material or product ≤ 50%. Biomass-derived materials such as starch derivatives, cellulose derivatives, chitin derivatives, and the mass content of biomass-derived materials in the entire thermoplastic starch-based biomass composite material or product ≤ the mass content of biomass material. Biodegradable synthetic polymers such as polybutylene adipate terephthalate, polybutylene succinate, polylactic acid, polycaprolactone, polyhydroxybutyric acid, etc., and the mass content of biodegradable synthetic polymers in the entire thermoplastic starch-based biomass composite material or product ≤ the mass content of biomass material.

[0025] For the thermoplastic starch-based biomass composite material or product of the present invention, the melting point of the biodegradable synthetic polymer must ≤ 140°C.

[0026] For the thermoplastic starch-based biomass composite material or product of the present invention, the mass ratio of N-methylmorpholine-N-oxide to urea is preferably 3:1 - 1:1.

[0027] The thermoplastic starch-based biomass composite material or product of the present invention is formed into a product by thermoplastic extrusion or thermoplastic injection molding.

[0028] A preparation method of a thermoplastic starch-based biomass composite material or product successively includes the following steps:

[0029] (1) Heat and mix starch, urea, and N-methylmorpholine-N-oxide liquid;

[0030] (2) Mix solidly with cellulose material, protein material, or chitin material;

[0031] (3) Use a screw extruder to melt, mix, and extrude to obtain a thermoplastic starch-based biomass composite material;

[0032] (4) Then use an injection molding machine to thermoplastically inject and mold into a thermoplastic starch-based biomass composite product.

[0033] The preparation method of the thermoplastic starch-based biomass composite material or product of the present invention may also include the following steps in sequence:

[0034] (1) Mix starch, urea, and N-methylmorpholine-N-oxide liquid, and use a screw extruder to melt and mix into a thermoplastic starch material;

[0035] (2) Use a screw extruder to melt, mix, and extrude the thermoplastic starch material with cellulose material, protein material, or chitin material to obtain a thermoplastic starch-based biomass composite material;

[0036] (3) Use an injection molding machine to thermoplastically inject and mold into a thermoplastic starch-based biomass composite product.

[0037] Of course, other suitable preparation methods can also be used for the thermoplastic starch-based biomass composite material or product of the present invention.

[0038] For the preparation method of the thermoplastic starch-based biomass composite material or product of the present invention, the content of N-methylmorpholine-N-oxide in the N-methylmorpholine-N-oxide liquid must be ≥ 75%. The content of N-methylmorpholine-N-oxide in the N-methylmorpholine-N-oxide liquid is preferably ≥ 80%. For example, the N-methylmorpholine-N-oxide liquid is N-methylmorpholine-N-oxide monohydrate.

[0039] In the preparation method of the thermoplastic starch-based biomass composite material or product of the present invention, the melting and mixing temperature of the screw extruder must be ≤ 140 °C, preferably 100 - 120 °C. The injection molding temperature of the injection molding machine must be ≤ 140 °C, preferably 100 - 120 °C. In addition to extrusion injection molding, the thermoplastic starch-based biomass composite material of the present invention can be formed into the thermoplastic starch-based biomass composite product by thermoplastic processing methods such as pressing and calendering. Among them, the thermoplastic molding temperature must be ≤ 140 °C, preferably 100 - 120 °C.

[0040] Example 1

[0041] 180 g of corn starch and 120 g of N-methyl morpholine-N-oxide hydrate containing 13.5% water were heated to 100 °C for mixing and kept for one hour. After cooling, they were broken into particles, and then solid-state mixed with 200 g of dried commercially available corn starch and 5 g of antioxidant 1010 at room temperature. They were melt-blended and extruded using a twin-screw extruder at 120 °C, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 8.69 MPa.

[0042] Example 2

[0043] 120 g of wheat flour, 80 g of N-methyl morpholine-N-oxide hydrate containing 13.5% water and 40 g of urea were heated to 100 °C for mixing and kept for 1 hour. After cooling, they were broken into particles, and then solid-state mixed with 260 g of dried commercially available wheat flour and 5 g of antioxidant 1010. They were melt-blended and extruded using a twin-screw extruder at 120 °C, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 14.9 MPa.

[0044] Example 3

[0045] 120 g of wheat flour, 80 g of N-methyl morpholine-N-oxide hydrate containing 13.5% water and 40 g of urea were heated to 100 °C for mixing and kept for 1 hour. After cooling, they were broken into particles, and then mixed with 160 g of dried commercially available wheat flour, 100 g of polylactic acid fiber cut into 10 mm in length and 5 g of antioxidant 1010. They were melt-blended and extruded using a twin-screw extruder at 120 °C, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 13.8 MPa.

[0046] Example 4

[0047] 120 g of wheat flour was mixed with 80 g of N-methylmorpholine-N-oxide hydrate containing 13.5% water and 40 g of urea, heated to 100 °C, maintained for 1 hour, cooled and broken into particles, and then mixed with 160 g of dried commercial wheat flour, 100 g of viscose fiber cut into 10 mm in length, and 5 g of antioxidant 1010. It was melt-blended and extruded at 120 °C using a twin-screw extruder, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 21.2 MPa.

[0048] Example 5

[0049] 120 g of wheat flour was mixed with 80 g of N-methylmorpholine-N-oxide hydrate containing 13.5% water and 40 g of urea, heated to 100 °C, maintained for 1 hour, cooled and broken into particles, and then mixed with 160 g of dried commercial wheat flour, 100 g of cotton yarn fiber cut into 10 mm in length, and 5 g of antioxidant 1010. It was melt-blended and extruded at 120 °C using a twin-screw extruder, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 25.7 MPa.

[0050] Example 6

[0051] 120 g of wheat flour was mixed with 80 g of N-methylmorpholine-N-oxide hydrate containing 13.5% water and 40 g of urea, heated to 100 °C, maintained for 1 hour, cooled and broken into particles, and then mixed with 160 g of dried commercial wheat flour, 100 g of bamboo powder, and 5 g of antioxidant 1010. It was melt-blended and extruded at 120 °C using a twin-screw extruder, cooled by cold air and then sent to a pelletizer for pelletizing. The pellets were injection-molded at 120 °C using an injection molding machine to obtain the thermoplastic starch-based biomass composite material of the present invention. The tensile strength of the injection-molded tensile spline after being kept at a constant temperature and humidity of 23 °C and 50% relative humidity for 24 hours was 18.6 MPa.

Claims

1. A thermoplastic starch-based biomass composite material or product, characterized in that: It contains 70% - 84% of biomass material, 16% - 24% of N-methyl morpholine-N-oxide, and 0% - 8% of urea.

2. The thermoplastic starch-based biomass composite material or product according to claim 1, characterized in that: The biomass material is one or more of starch material, cellulose material, protein material, and chitin material.

3. The thermoplastic starch-based biomass composite material or product according to claim 1 or 2, characterized in that: It contains one or more of inorganic filler, biomass-derived material, and biodegradable synthetic polymer.

4. The thermoplastic starch-based biomass composite material or product according to any one of claims 1 to 3, characterized in that: The melting point of the biodegradable synthetic polymer is ≤ 140°C.

5. The thermoplastic starch-based biomass composite material or product according to any one of claims 1 to 4, characterized in that: The mass ratio of N-methyl morpholine-N-oxide to urea is 3:1 - 1:

1.

6. The thermoplastic starch-based biomass composite material or product according to any one of claims 1 to 5, characterized in that: It is formed into a product by thermoplastic extrusion or thermoplastic injection molding.

7. The preparation method of the thermoplastic starch-based biomass composite material or product according to any one of claims 1 to 6, characterized in that: It successively includes the following steps: (1) Heat and mix starch, urea, and liquid N-methyl morpholine-N-oxide. (2) Solid-state mix with cellulose material, protein material, or chitin material. (3) Use a screw extruder to melt and mix and extrude to obtain a thermoplastic starch-based biomass composite material. (4) Then use an injection molding machine for thermoplastic injection molding to become a thermoplastic starch-based biomass composite product.

8. The preparation method of the thermoplastic starch-based biomass composite material or product according to any one of claims 1 to 6, characterized in that: It successively includes the following steps: (1) Mix starch, urea, and liquid N-methyl morpholine-N-oxide, and use a screw extruder to melt and mix into a thermoplastic starch material. (2) Use a screw extruder to melt and mix and extrude the thermoplastic starch material with cellulose material, protein material, or chitin material to obtain a thermoplastic starch-based biomass composite material. (3) Use an injection molding machine for thermoplastic injection molding to become a thermoplastic starch-based biomass composite product.

9. The preparation method of the thermoplastic starch-based biomass composite material or product according to claim 7 or 8, characterized in that: The content of N-methyl morpholine-N-oxide in the liquid N-methyl morpholine-N-oxide is ≥ 75%.

10. The preparation method of the thermoplastic starch-based biomass composite material or product according to any one of claims 7 to 9, characterized in that: The melting and mixing temperature of the screw extruder is ≤ 140°C, and the injection molding temperature of the injection molding machine is ≤ 140°C.