Preparation method of environment-friendly tableware

Abstract

The present application relates to a kind of preparation methods of environment-friendly tableware, belong to environment-friendly material field, comprising the following steps: A, by mass fraction, 50-75 parts of starch, 1,2-pentanediol 5-10 parts and glycerol 5-10 parts are mixed after stirring, extrusion granulation, obtain modified starch;B, take the modified starch 30-40 parts obtained in step A, with polylactic acid 30-50 parts, polybutylene adipate terephthalate 20-50 parts, plant fiber 12-20 parts, polyethylene glycol 5-10 parts, magnesium aluminum silicate 1-2 parts, silane coupling agent 2-3 parts and filler 2-10 parts are mixed stirring, melt extrusion, granulation, injection molding, it is prepared to obtain environment-friendly tableware.The environment-friendly tableware of the present application is mainly polylactic acid, polybutylene adipate terephthalate and modified starch, complementary advantages of three, and the prepared tableware has excellent degradable performance, and good mechanical property.

Description

Technical Field

[0001] This invention relates to a method for preparing environmentally friendly tableware, belonging to the field of environmentally friendly materials. Background Technology

[0002] With increasing attention to the environment, the use of traditional disposable tableware materials has been largely restricted. As a result, the market has introduced biodegradable materials to prepare disposable tableware. The raw materials for existing biodegradable disposable tableware are mostly polylactic acid (PLA), starch, plant fiber, or PBAT.

[0003] To address the degradation issue of disposable tableware, several solutions have been proposed in the industry. The most common approach involves using plant fibers such as straw and rice straw, and starches such as corn starch as the main raw materials. However, during the pulping process, plant fibers develop numerous micropores on their cell walls, resulting in poor mechanical properties, particularly impact resistance, in the tableware. Furthermore, their excessive surface wettability and hydrophilicity lead to poor water resistance. Once manufactured, these materials quickly oxidize and break down polymer bonds due to direct contact with surrounding moisture and air, causing rapid aging, reduced strength, and rendering them unusable.

[0004] Polylactic acid (PLA) is a novel biodegradable material. It is widely popular due to its abundant and renewable sources, and the fact that the only degradation products of PLA are water and carbon dioxide, causing no environmental pollution. Furthermore, PLA's thermoplasticity makes it an excellent material for disposable tableware. Despite its excellent properties, PLA is a semi-crystalline polymer. Due to its extremely slow crystallization rate and rapid cooling rate during conventional processing, it often becomes amorphous after processing, thus inherently becoming brittle. Compared to traditional petroleum polymers, PLA's properties (such as vapor / gas barrier properties, impact resistance, and melt viscosity) are generally insufficient, limiting its functional applications.

[0005] To solve this technical problem, it is necessary to propose improvements to these environmentally friendly materials. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a method for preparing environmentally friendly tableware, so that the prepared tableware has excellent biodegradability and good mechanical properties.

[0007] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0008] Technical Topic 1

[0009] 2. A method for preparing environmentally friendly tableware, characterized by comprising the following steps:

[0010] A. By mass, 50-75 parts of starch, 5-10 parts of 1,2-pentanediol and 5-10 parts of glycerol are mixed and stirred, then extruded and granulated to obtain modified starch.

[0011] B. Take 30-40 parts of the modified starch obtained in step A, mix it with 30-50 parts of polylactic acid, 20-50 parts of polybutylene terephthalate-adipate, 12-20 parts of plant fiber, 5-10 parts of polyethylene glycol, 1-2 parts of magnesium aluminum silicate, 2-3 parts of silane coupling agent and 2-10 parts of filler, stir and mix, melt extrude, granulate and injection mold to prepare environmentally friendly tableware.

[0012] In a preferred embodiment of the present invention, the stirring rate is 320-450 r / min, and the stirring time is 1-1.5 h. In a preferred embodiment of the present invention, the extrusion temperature of the twin-screw extruder in step A is 130-155℃, and the screw speed is 90-120 r / min.

[0013] The extrusion temperature of the twin-screw extruder in step B is 160-175℃, and the screw speed is 90-120 r / min.

[0014] In a preferred embodiment of the present invention, the starch in step A undergoes a drying pretreatment; before step B, the modified starch, polylactic acid, polybutylene terephthalate, and plant fiber are also vacuum dried.

[0015] As a preferred embodiment of the present invention, the silane coupling agent is allyltrimethoxysilane or n-butyltrimethoxysilane in a mass ratio of 2:0.7-1.5.

[0016] In a preferred embodiment of the present invention, the polylactic acid has a weight-average molecular weight of 200,000-300,000 and a melt index of 3-30 g / 10 min; the polybutylene terephthalate has a weight-average molecular weight of 150,000-200,000.

[0017] In a preferred embodiment of the present invention, the average molecular weight of the polyethylene glycol is 4000-6000.

[0018] In a preferred embodiment of the present invention, the plant fiber is selected from one or more of straw fiber, bamboo fiber and wood pulp fiber.

[0019] In a preferred embodiment of the present invention, the average particle size of the plant fiber is 10-50 μm.

[0020] In a preferred embodiment of the present invention, the starch is selected from one or more of corn starch, wheat starch, and potato starch.

[0021] In a preferred embodiment of the present invention, the filler is selected from one or more of calcium carbonate, silicon dioxide and titanium dioxide.

[0022] In a preferred embodiment of the present invention, the filler is 800-1000 mesh.

[0023] The beneficial effects of adopting the above technical solution are as follows:

[0024] The environmentally friendly tableware prepared by this invention adopts the GB / T 19276.1-2003 standard, simulates the biodegradation process in a natural water-containing environment, achieves a biodegradation rate of 85-90%, and has excellent mechanical properties.

[0025] This invention blends polylactic acid (PLA) with starch and polybutylene terephthalate (PET), which improves the toughness of PLA without sacrificing its biodegradability. The addition of plant fibers further enhances the mechanical properties of the plastic. Starch is an inexpensive, readily available, and biodegradable natural polymer. The large number of hydroxyl groups in native starch creates extremely strong intramolecular and intermolecular hydrogen bonds, resulting in poor thermoplasticity and insufficient shear stability. PLA and some biodegradable substances have very low polarity and are hydrophobic, leading to poor compatibility. Furthermore, PLA and PET also have poor compatibility, hindering stress transfer between interfaces under stress.

[0026] To improve the compatibility of the three components, this invention not only uses physical means such as mechanical force to disrupt the structure of starch, but also adds 1,2-pentanediol and glycerol. Under strong shear force, these substances penetrate between starch molecules to disrupt the ring structure of the starch crystalline region. The hydrogen bonds between and within starch molecules are replaced by the hydrogen bonds between 1,2-pentanediol and glycerol and starch, reducing the rigidity of starch, enhancing its plasticity, and improving the compatibility of starch with polylactic acid and polybutylene terephthalate, thereby achieving plasticization modification.

[0027] In this invention, the addition of plant fibers promotes the soil-borne degradation of polylactic acid (PLA). Allyltrimethoxysilane and n-butyltrimethoxysilane contain both organic active functional groups and hydrolyzable inorganic functional groups. The organic active functional groups in their structure can tightly intertwine with the molecular chains of PLA, polybutylene terephthalate (PET), and modified starch, while the hydrolyzable inorganic groups can combine with inorganic materials (such as fillers and plant fibers), thus acting as bridges and links within the material. This makes the two-phase molecular chains within the material more tightly bound together, effectively dispersing and transmitting force under external impact, thereby improving the performance of the composite material. Furthermore, the association between allyltrimethoxysilane and n-butyltrimethoxysilane makes the internal network structure of the material more compact, and the increased intermolecular forces require more energy for decomposition, thus improving the thermal stability of the composite material.

[0028] In this invention, polyethylene glycol is mixed with plant fibers, which allows the plant fibers to be uniformly dispersed in the polylactic acid matrix, increases the compatibility between plant fibers and polylactic acid, and improves the toughness of polylactic acid composite materials.

[0029] The filler added in this invention serves a filling function, reduces the "cavitation" effect, and improves the mechanical properties of the material. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the present invention clearer, the invention will be described clearly and completely below in conjunction with specific embodiments.

[0031] In the embodiments and comparative examples of this invention, the polylactic acid used has a weight-average molecular weight of 200,000-300,000 and a melt index of 3-30 g / 10 min; the polybutylene terephthalate (PET) has a weight-average molecular weight of 150,000-200,000; the plant fiber has an average particle size of 10-50 μm; the calcium carbonate, silicon dioxide, and titanium dioxide all have a particle size of 800-1000 mesh; the starch preferably has a moisture content of 5-8 wt%; the plant fiber preferably has a moisture content of less than 5 wt%; and other raw materials can be purchased commercially.

[0032] Example 1

[0033] A method for preparing environmentally friendly tableware includes the following steps:

[0034] A. First, dry the starch at 80℃ for 30 min; then, by mass, mix 50 parts starch, 10 parts 1,2-pentanediol and 5 parts glycerol, stir at a stirring rate of 450 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 155℃ and a screw speed of 90 r / min to obtain modified starch.

[0035] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 90°C for 4 hours; the filler and plant fiber are vacuum dried at 100°C for 7 hours.

[0036] Take 40 parts of the modified starch obtained in step A, mix it with 30 parts of polylactic acid, 50 parts of polybutylene terephthalate-adipate, 12 parts of plant fiber, 10 parts of polyethylene glycol, 1 part of magnesium aluminum silicate, 3 parts of silane coupling agent and 2 parts of filler, and stir at a stirring rate of 450 r / min for 1 h. Then, melt extrude the mixture using a twin-screw extruder at a temperature of 175℃ and a screw speed of 90 r / min. Granulate the mixture and then injection mold it to obtain environmentally friendly tableware.

[0037] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1.5; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber; the starch is potato starch; and the filler is calcium carbonate.

[0038] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0039] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0040] The results are shown below.

[0041] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 1 86 456 24.7

[0042] Example 2

[0043] A method for preparing environmentally friendly tableware includes the following steps:

[0044] A. First, the starch is dried at 60℃ for 1 hour; then, by mass, 75 parts of starch, 5 parts of 1,2-pentanediol and 10 parts of glycerol are mixed and stirred at a stirring rate of 320 r / min for 1.5 hours. Then, the mixture is extruded and granulated using a twin-screw extruder at a temperature of 130℃ and a screw speed of 120 r / min to obtain modified starch.

[0045] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 60°C for 5 hours; the filler and plant fiber are vacuum dried at 90°C for 8 hours.

[0046] Take 30 parts of the modified starch obtained in step A, and mix it with 50 parts of polylactic acid, 20 parts of polybutylene terephthalate-adipate, 20 parts of plant fiber, 5 parts of polyethylene glycol, 2 parts of magnesium aluminum silicate, 2 parts of silane coupling agent and 10 parts of filler. Mix and stir at a stirring rate of 320 r / min for 1.5 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 160℃ and a screw speed of 120 r / min. Granulation and injection molding are then performed to obtain environmentally friendly tableware.

[0047] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:0.7; the average molecular weight of polyethylene glycol is 6000; the plant fiber is bamboo fiber, the starch is corn starch, and the filler is titanium dioxide.

[0048] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0049] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0050] The results are shown below.

[0051] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 2 85 462 25.6

[0052] Example 3

[0053] A method for preparing environmentally friendly tableware includes the following steps:

[0054] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0055] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0056] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0057] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silicon dioxide and titanium dioxide in a mass ratio of 1:1.2.

[0058] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0059] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0060] The results are shown below.

[0061] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 3 90 504 30.2

[0062] Example 4

[0063] A method for preparing environmentally friendly tableware includes the following steps:

[0064] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0065] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0066] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0067] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is titanium dioxide.

[0068] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0069] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0070] The results are shown below.

[0071] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 4 84 481 28.9

[0072] Example 5

[0073] A method for preparing environmentally friendly tableware includes the following steps:

[0074] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0075] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0076] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0077] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silicon dioxide.

[0078] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0079] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0080] The results are shown below.

[0081] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 5 85 473 27.3

[0082] Example 6

[0083] A method for preparing environmentally friendly tableware includes the following steps:

[0084] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0085] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0086] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0087] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is calcium carbonate.

[0088] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0089] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0090] The results are shown below.

[0091] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Example 6 85 468 26.1

[0092] Comparative Example 1

[0093] A method for preparing environmentally friendly tableware includes the following steps:

[0094] A. First, dry the starch at 90℃ for 30 min; then, mix 55 parts starch and 17 parts glycerol by mass, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0095] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0096] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0097] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silicon dioxide and titanium dioxide in a mass ratio of 1:1.2.

[0098] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0099] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0100] The results are shown below.

[0101] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 1 84 325 12.5

[0102] Comparative Example 2

[0103] A method for preparing environmentally friendly tableware includes the following steps:

[0104] A. First, dry the starch at 90℃ for 30 min; then, mix 55 parts starch and 17 parts 1,2-pentanediol by mass, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0105] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0106] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0107] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silicon dioxide and titanium dioxide in a mass ratio of 1:1.2.

[0108] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0109] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0110] The results are shown below.

[0111] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 2 82 334 13.3

[0112] Comparative Example 3

[0113] A method for preparing environmentally friendly tableware includes the following steps:

[0114] Starch, polylactic acid, and polybutylene terephthalate were vacuum dried at 80°C for 5 hours; filler and plant fiber were vacuum dried at 100°C for 8 hours.

[0115] Take 35 parts of starch, 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent, and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 hour. Then, melt extrude the mixture using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulate the mixture and then injection mold it to obtain environmentally friendly tableware.

[0116] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silicon dioxide and titanium dioxide in a mass ratio of 1:1.2.

[0117] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0118] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0119] The results are shown below.

[0120] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 3 80 215 9.3

[0121] Comparative Example 4

[0122] A method for preparing environmentally friendly tableware includes the following steps:

[0123] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0124] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0125] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0126] The silane coupling agent is n-butyltrimethoxysilane; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silica and titanium dioxide in a mass ratio of 1:1.2.

[0127] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0128] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0129] The results are shown below.

[0130] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 4 82 432 21.5

[0131] Comparative Example 5

[0132] A method for preparing environmentally friendly tableware includes the following steps:

[0133] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0134] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0135] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, 2.5 parts of silane coupling agent and 5 parts of filler. Mix and stir at a stirring rate of 350 r / min for 1 h. Melt extrusion is performed using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulation and injection molding are then performed to prepare environmentally friendly tableware.

[0136] The silane coupling agent is allyltrimethoxysilane; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the filler is silica and titanium dioxide in a mass ratio of 1:1.2.

[0137] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0138] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0139] The results are shown below.

[0140] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 5 83 405 18.2

[0141] Comparative Example 6

[0142] A method for preparing environmentally friendly tableware includes the following steps:

[0143] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0144] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the filler and plant fiber are vacuum dried at 100°C for 8 hours.

[0145] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate and 5 parts of filler. Mix the mixture at a stirring rate of 350 r / min for 1 h, and then melt-extrude it using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulate the mixture and then injection mold it to obtain environmentally friendly tableware.

[0146] The average molecular weight of the polyethylene glycol is 4000; the plant fiber is straw fiber, the starch is wheat starch, and the fillers are silicon dioxide and titanium dioxide in a mass ratio of 1:1.2.

[0147] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0148] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0149] The results are shown below.

[0150] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 6 81 396 17.7

[0151] Comparative Example 7

[0152] A method for preparing environmentally friendly tableware includes the following steps:

[0153] A. First, dry the starch at 90℃ for 30 min; then, according to the mass fraction, mix 55 parts of starch, 8 parts of 1,2-pentanediol and 9 parts of glycerol, stir at a stirring rate of 400 r / min for 1 h, and then extrude and granulate using a twin-screw extruder at a temperature of 150℃ and a screw speed of 100 r / min to obtain modified starch.

[0154] B. The modified starch, polylactic acid, and polybutylene terephthalate obtained in step A are vacuum dried at 80°C for 5 hours; the plant fiber is vacuum dried at 100°C for 8 hours.

[0155] Take 35 parts of the modified starch obtained in step A, and mix it with 45 parts of polylactic acid, 45 parts of polybutylene terephthalate-adipate, 15 parts of plant fiber, 8 parts of polyethylene glycol, 1.5 parts of magnesium aluminum silicate, and 2.5 parts of silane coupling agent. Mix and stir at a stirring rate of 350 r / min for 1 h. Then, melt extrude the mixture using a twin-screw extruder at a temperature of 170℃ and a screw speed of 100 r / min. Granulate the mixture and then injection mold it to obtain environmentally friendly tableware.

[0156] The silane coupling agent is allyltrimethoxysilane and n-butyltrimethoxysilane in a mass ratio of 2:1; the average molecular weight of polyethylene glycol is 4000; the plant fiber is straw fiber and the starch is wheat starch.

[0157] The environmentally friendly tableware material obtained by this invention was cut into strips with a length of 40 mm, a width of 5 mm, and a thickness of 0.5 mm. The degradation rate of the environmentally friendly tableware materials prepared in each embodiment and comparative example was tested according to the GB / T 19276.1-2003 standard.

[0158] According to GB / T1040-2018 Determination of Tensile Properties of Plastics, the longitudinal elongation at break and tensile strength at break of the sheet were tested at a speed of 20 mm / min using an electronic tensile testing machine.

[0159] The results are shown below.

[0160] project 120-day degradation rate % Elongation at break % Tensile strength at break (MPa) Comparative Example 7 86 382 16.3

[0161] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing environmentally friendly tableware, characterized in that: Includes the following steps: A. By mass, 50-75 parts of starch, 5-10 parts of 1,2-pentanediol and 5-10 parts of glycerol are mixed and stirred, then extruded and granulated to obtain modified starch. B. Take 30-40 parts of the modified starch obtained in step A, mix it with 30-50 parts of polylactic acid, 20-50 parts of polybutylene terephthalate-adipate, 12-20 parts of plant fiber, 5-10 parts of polyethylene glycol, 1-2 parts of magnesium aluminum silicate, 2-3 parts of silane coupling agent and 2-10 parts of filler, stir and mix, melt extrude, granulate, and injection mold to prepare environmentally friendly tableware; The silane coupling agent is allyltrimethoxysilane or n-butyltrimethoxysilane in a mass ratio of 2:0.7-1.5; The filler is selected from one or more of calcium carbonate, silicon dioxide and titanium dioxide, and the filler is 800-1000 mesh.

2. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The stirring rate is 320-450 r / min, and the stirring time is 1-1.5 h.

3. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The extrusion temperature in step A is 130-155℃; the extrusion temperature in step B is 160-175℃.

4. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The starch in step A undergoes a drying pretreatment; before step B, the modified starch, polylactic acid, polybutylene terephthalate, filler, and plant fiber are also vacuum dried.

5. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The polylactic acid has a weight-average molecular weight of 200,000-300,000 and a melt index of 3-30 g / 10 min; the polybutylene terephthalate has a weight-average molecular weight of 150,000-200,000.

6. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The average molecular weight of the polyethylene glycol is 4000-6000.

7. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The plant fiber is selected from one or more of straw fiber, bamboo fiber and wood pulp fiber, and the average particle size of the plant fiber is 10-50 μm.

8. The method for preparing an environmentally friendly tableware according to claim 1, characterized in that: The starch is selected from one or more of corn starch, wheat starch, and potato starch.