Bio-based composite materials and method for manufacturing the same

Abstract

To provide a bio-based composite material with excellent mechanical properties and high environmental performance.SOLUTION: A bio-based composite material comprises: 45 to 75 pts.wt. of polypropylene; and 25 to 55 pts.wt. of biomass material, wherein the biomass material is any one of or a combination of two or three of a plasticized starch, a modified biogenic calcium, and a modified cellulose. The bio-based composite material further comprises: 1 to 3 pts.wt. of a linear low-density polyethylene as a modifier; 3 to 5 pts.wt. of an ethylene-vinyl acetate copolymer as a modifier; 2 to 3 pts.wt. of a monoglyceride as a surfactant; 2 to 3 pts.wt. of a polyethylene wax as a modifier; 2 to 3 pts.wt. of a silane coupling agent as a modifier; 0.1 to 0.2 pts.wt. of an antioxidant; and 0 to 3 pts.wt. of a polypropylene graft maleic anhydride as a modifier.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to polymeric material products, and in particular to bio-based composite materials and methods for their manufacture. [Background technology]

[0002] With the improvement of environmental protection performance and the implementation of environmental protection policies, the use of petroleum-based plastics in the field of disposable plastic products is being increasingly restricted, mainly due to the ever-increasing price of raw materials, the ever-increasing requirements for the decomposition of plastic products, and the need to reduce carbon dioxide emissions.

[0003] In response to the above-mentioned societal demands, technology is being developed for producing plastic products with desired performance by mixing various biodegradable raw materials with petroleum-based polymer compound materials.

[0004] For example, Patent Document 1 proposes a composition for producing bioplastics containing ethanol-derived polyethylene, starch, and a biodegradable additive, or a composition further containing plant-derived raw materials such as calcium carbonate, hemp hurd, and soy protein.

[0005] Furthermore, for example, Patent Document 2 describes the production of a sheet- or plate-shaped molded body using a raw material obtained by mixing starch as a main component, or starch and vegetable cellulose as main components, a foaming plastic containing polypropylene, and a modifier for the mixture containing the main component and the foaming plastic, which contains an acrylic modified polytetrafluoroethylene.

[0006] Also, for example, Patent Document 3 proposes a method for producing a natural fiber / starch thermoplastic composite, in which wet natural fibers containing a certain total amount of natural fibers, a certain total amount of starch, and a certain total amount of plasticizer are mixed with water to form a paste, and the paste is blended with a certain total amount of thermoplastic to form the composite. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2023-511750 [Patent Document 2] JP 2020-094189 A [Patent Document 3] JP 2017-516882 A Summary of the Invention [Problem to be solved by the invention]

[0008] Now, let us consider the production of a bio-based composite material with excellent environmental performance by adding biomass materials to polypropylene. If starch, cellulose, and biological calcium are used as the biomass materials, starch, cellulose, and biological calcium are polar materials, but polypropylene is a non-polar material.

[0009] When starch, cellulose and bio-calcium are melt-mixed with petroleum-based polypropylene, the two are poorly miscible due to the difference in polarity, and the resulting composite product may have many defects, such as air bubbles in the composite, uneven distribution of starch, cellulose and bio-calcium, poor mechanical properties of the composite, and very brittle material.

[0010] In this regard, Patent Document 1 describes that hemp hurd can be more uniformly blended and mixed with other base copolymers when it is ground into a fine powder with a diameter of about 0.25 to 0.75 microns, but does not mention the miscibility of starch, biological calcium, and base copolymers. Patent Document 2 describes the addition of a modifier to improve the compatibility of a mixture containing starch and / or plant cellulose, but does not mention biological calcium. Patent Document 3 also describes the addition of a plasticizer to starch and wet natural fibers and mixing them with thermoplastics, but does not mention biological calcium.

[0011] In order to solve the above and other problems, one object of the present invention is to provide a bio-based composite material and a manufacturing method thereof, which is obtained by blending polypropylene with a biomass material such as plasticized starch, modified biological calcium, or modified cellulose, and further adding various modifiers and surfactants, and which has mechanical properties and heat resistance equivalent to those of polypropylene, is biodegradable, and reduces carbon emissions. [Means for solving the problem]

[0012] In order to achieve the above and other objects, a bio-based composite material according to one embodiment of the present invention comprises 45 to 75 parts by weight of polypropylene and 25 to 55 parts by weight of a biomass material, the biomass material being any one or a combination of two or three of plasticized starch, modified biological calcium, and modified cellulose, and further comprising 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of a silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of an antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier.

[0013] In addition, a method for producing a bio-based composite material according to one embodiment of the present invention includes producing any one of plasticized starch, modified biological calcium, and modified cellulose, or two or three of them, and producing a mixture of 45 to 75 parts by weight of polypropylene, 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier, and adding and mixing 25 to 55 parts by weight of any one of the plasticized starch, modified biological calcium, and modified cellulose, or a combination of two or three of them, to the mixture to produce a mixed raw material, which is then kneaded, extruded, cut, pelletized, and dried. Effect of the Invention

[0014] According to the present invention, a bio-based composite material is provided which has mechanical properties and heat resistance equivalent to those of polypropylene, is biodegradable, and reduces carbon emissions, by blending polypropylene with a biomass material such as plasticized starch, modified biological calcium, or modified cellulose, and further adding various modifiers and surfactants, and which has the same properties as polypropylene, is biodegradable, and reduces carbon emissions, and a method for producing the same is provided. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a flow chart illustrating a production process of a bio-based composite material in this embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of the configuration of a twin-screw extruder used in producing the bio-based composite material of this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the present invention will be described in detail based on embodiments and examples with reference to the drawings.

[0017] A bio-based composite material according to one embodiment of the present invention comprises 45 to 75 parts by weight of polypropylene and 25 to 55 parts by weight of a biomass material, the biomass material being any one or a combination of two or three of plasticized starch, modified biological calcium, and modified cellulose, and further comprising 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of a silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of an antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier.

[0018] Here, "modification" means modifying the surface of cellulose and biological calcium using additives such as crosslinking agents and surfactants to improve compatibility with polypropylene, toughness, strength, etc.

[0019] Ethylene-vinyl acetate copolymer is a plasticizer for modifying polypropylene, improving its elasticity, flexibility, glossiness, and breathability. It also increases the resistance of polypropylene to cracking caused by external forces and improves its compatibility with biomass materials. To prevent or reduce the deterioration of the mechanical properties of polypropylene, other fillers may be added to reinforce it.

[0020] Monoglyceride and polyethylene wax are lubricants. Antioxidants prevent oxidation and decomposition of materials during the manufacturing process. Silane coupling agents and polypropylene grafted maleic anhydride are crosslinking agents that improve the compatibility of polypropylene with biomass materials.

[0021] The weight percentage of the polypropylene in the bio-based composite material can be between 40 and 60%, and the weight percentage of the biomass material in the bio-based composite material can be between 40 and 60%.

[0022] The polypropylene may be a homopolymer.

[0023] The plasticized starch is a mixture of starch, sodium aluminate, water, glycerin, and polyethylene glycol 400, and the weight ratio of starch, sodium aluminate, water, glycerin, and polyethylene glycol can be 250:1 to 2:25 to 35:40 to 50:10 to 30.

[0024] The modified biogenic calcium may include seashell powder or eggshell powder.

[0025] The modified cellulose is a mixture of wood pulp cellulose, an aluminate ester coupling agent, glycerin, and stearic acid, and the mass ratio of the wood pulp cellulose, the aluminate ester coupling agent, the glycerin, and the stearic acid may be 30:1 to 3:2 to 4:0.3 to 0.5.

[0026] The silane coupling agent may be methyltrimethoxysilane.

[0027] The antioxidant can be tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0028] In one embodiment of the present invention, a method for producing a bio-based composite material includes producing one or two or three of plasticized starch, modified biological calcium, and modified cellulose, and producing a mixture of 45 to 75 parts by weight of polypropylene, 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier, and adding 25 to 55 parts by weight of one or a combination of two or three of the plasticized starch, modified biological calcium, and modified cellulose to the mixture and mixing to produce a mixed raw material, which is kneaded, extruded, cut, pelletized, and dried. The moisture content of the produced pellets can be 1% or less.

[0029] The plasticized starch is produced by mixing starch, sodium aluminate, and water, drying, and then adding glycerin and polyethylene glycol 400, and high-speed mixing, drying, and granulating. In the obtained plasticized starch, the weight ratio of starch, sodium aluminate, water, glycerin, and polyethylene glycol can be 250:1-2:25-35:40-50:10-30.

[0030] The modified biological calcium may be produced by removing impurities from seashells or eggshells, washing them thoroughly with water, drying them at 100°C, crushing and sieving them to obtain 100 mesh seashell powder or eggshell powder, dissolving 1 to 3 parts by weight of caprolactam in absolute ethanol at a concentration of 10%, adding 100 parts by weight of the 100 mesh seashell powder or eggshell powder to cold mix, then mixing at 100°C to remove ethanol, and drying.

[0031] The modified cellulose may be obtained by obtaining wood pulp cellulose after dehydration and drying, adding an aluminate ester coupling agent and glycerin, mixing and stirring, and then adding and mixing stearic acid to obtain the modified wood pulp cellulose, and the mass ratio of the wood pulp cellulose, the aluminate ester coupling agent, the glycerin, and the stearic acid may be 30:1 to 3:2 to 4:0.3 to 0.5.

[0032] The plasticized starch, modified biological calcium, and modified cellulose obtained as described above have excellent surface compatibility with polypropylene.

[0033] A mixed raw material obtained by mixing any one or two or three of the plasticized starch, the modified biological calcium, and the modified cellulose with the polypropylene, the linear low-density polyethylene, the ethylene-vinyl acetate copolymer, the monoglyceride, the polyethylene wax, the silane coupling agent, the antioxidant, and the polypropylene-grafted maleic anhydride may be kneaded and heated in a kneading and heating step, and the kneading and heating step may be divided into a first section to an eighth section from an inlet to an outlet, and the temperatures of the first section to the eighth section may be set in the ranges of 165 to 175°C, 165 to 170°C, 170 to 175°C, 170 to 175°C, 170 to 175°C, 165 to 170°C, 165 to 170°C, and 165 to 170°C, respectively, and the temperature of the outlet may be set to 170 to 175°C. The temperature ranges set for the first through eighth sections can be determined experimentally. If the set temperatures are lower than the ranges, the mixture will not melt sufficiently and will not fuse sufficiently. If the set temperatures are higher than the ranges, the biomass material may be carbonized.

[0034] The weight ratio of polypropylene contained in the bio-based composite material is preferably 40 to 60%. The weight ratio of biomass material contained in the bio-based composite material is preferably 40 to 60%. This indicates that the preferred weight ratios of plasticized starch, modified biological calcium, and modified cellulose as biomass materials are each 40 to 60%.

[0035] According to the bio-based composite material of the embodiment of the present invention, polypropylene is mixed with any one or two or three of the biomass materials, such as plasticized starch, modified biological calcium, and modified cellulose, and various modifiers are further mixed in, thereby improving the compatibility between the polypropylene, which is a plastic substrate, and the surfaces of various biomass materials, and making the mechanical performance equivalent to that of polypropylene alone. In addition, under conditions that guarantee the mechanical performance and heat resistance of the material, the amount of biomass material added can be increased up to 60%, and the decomposition efficiency of the material can be improved up to 60%, and the material cost can also be reduced.

[0036] In addition, since the bio-based composite material according to the embodiment of the present invention is obtained in the form of pellets, it is suitable for conventional molding methods such as injection molding, hot pressing, blow molding, extrusion and blowing, and can be used to manufacture various electrical components, audio components, containers, products, tableware, packaging, etc., and has a wide range of applications.

[0037] Furthermore, the bio-based composite material according to the embodiment of the present invention can be decomposed and absorbed by microorganisms, and carbon emissions associated with disposal can be reduced by about 30% compared to polypropylene alone, so that it has a small environmental impact and good environmental and social value.

[0038] Next, the bio-based composite material according to the above embodiment and the method for producing the same will be described with reference to examples.

[0039] [Example] Production of various biomass materials A variety of biomass materials are described that can be mixed with polypropylene to produce the bio-based composite material of the present invention.

[0040] (1) Production of plasticized starch 15g of sodium aluminate was dissolved in 300ml of water, 2500g of starch was added, and the mixture was dried. Then, 450g of glycerin and 200g of polyethylene glycol 400 were added, and the mixture was mixed uniformly for 30 minutes, dried, and granulated. The granulation temperature was 90 to 125°C, and 3165g of plasticized starch was obtained.

[0041] (2) Production of biologically derived calcium (a) Production of modified shell powder The shells were cleaned of impurities, washed thoroughly with water, dried at 100°C, crushed and sieved to obtain 100 mesh shell powder.

[0042] First, 20 g of caprolactam was dissolved in 180 ml of absolute ethanol, added to 1000 g of 100 mesh seashell powder, cold mixed for 30 minutes, then mixed at 100°C for 30 minutes to remove the ethanol, and dried to obtain 1020 g of modified biogenic calcium.

[0043] (b) Manufacturing of modified eggshell powder The eggshells were cleaned of impurities, washed thoroughly with water, dried at 100°C, crushed and sieved to obtain 100 mesh eggshell powder.

[0044] First, 20 g of caprolactam was dissolved in 180 ml of absolute ethanol, added to 1000 g of 100 mesh eggshell powder, cold mixed for 30 min, then mixed at 100°C for 30 min to remove ethanol, and dried to obtain 1020 g of modified biogenic calcium.

[0045] (4) Manufacture of modified cellulose After dehydration and drying, 3,000 g of wood pulp cellulose was mixed with 200 g of an aluminate coupling agent and 300 g of glycerin, then added to a high-speed mixer and stirred, after which 40 g of stearic acid was added and mixed to obtain 3,540 g of modified wood pulp cellulose.

[0046] Manufacturing of bio-based composites Next, the production of a bio-based composite material using various biomass materials produced and prepared will be described. Figure 1 shows a flow chart of an example of a production process of a bio-based material according to an embodiment of the present invention. In the figure, the symbol S means a step.

[0047] First, plasticized starch is produced in step S10, modified biological calcium in step S20, and modified cellulose in step S30.

[0048] In step S40, any one or two or three of the plasticized starch, modified biological calcium, and modified cellulose produced in steps S10 to S30 are mixed with polypropylene.

[0049] In step S50, various additives are further mixed into the mixture produced in step S40.

[0050] In step S60, the mixture obtained in step S50 is charged at the inlet of a twin-screw extruder constituting a kneading and heating process, extruded from a die head (die) at the outlet into a heated atmosphere at a predetermined temperature, and pelletized by hot cutting. FIG. 2 shows a schematic plan view of a twin-screw extruder 100 in this embodiment. The twin-screw extruder 100 illustrated in FIG. 2 includes a pair of screws 140, a first section 120-1 to an eighth section 120-8, and a die head 130. The bio-based composite material mixture obtained in step S50 is supplied to the screw 140 through a supply section 110, which is an inlet, by a side supply hopper (not shown), and enters the first section 120-1 while being kneaded and heated. The first section 120-1 is maintained at a predetermined temperature T1. The kneaded mixture is sent to the second section 120-2 and the third section 120-3 in sequence. The second section 120-2 to the eighth section 120-8 are also maintained at predetermined temperatures T2 to T8, respectively. The mixture that reaches the outlet die head 130 while being heated is extruded through a plurality of fine holes and granulated by a cutter in step S70, and then dried and processed into pellets of the bio-based composite material.

[0051] For pelletization, a method of hot cutting the raw material extruded from the die head 130 can be adopted, but other pelletization methods such as strand cutting may also be adopted. Also, as described above, in the embodiment of the present invention, the twin screw extruder 100 is used for kneading and heating the mixed raw material, but other types of equipment such as a single screw extruder may also be used.

[0052] Next, the production of bio-based composite materials using various biomass materials will be specifically described.

[0053] Example 1: Production of bio-based composite materials using starch-based biomass materials 315 g of polypropylene, 20 g of linear low density polyethylene, 40 g of ethylene-vinyl acetate copolymer, 20 g of monoglyceride, 30 g of polyethylene wax, 20 g of silane coupling agent, 1 g of antioxidant, and 10 g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 685 g of plasticized starch was added, and after mixing for another 30 minutes, the mixture was added to the twin screw extruder 100 from the side feed hopper, and the mixed raw materials were kneaded, heated, and extruded through the die head 130, pelletized, and dried to obtain a bio-based composite material using starch-based biomass material.

[0054] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 165°C, T2 = 170°C, T3 = 170°C, T4 = 170°C, T5 = 170°C, T6 = 170°C, T7 = 165°C, and T8 = 165°C, and the temperature of the die head 130 was 170°C.

[0055] Example 2: Production of bio-based composite material using biological calcium-based biomass material 550g of polypropylene, 15g of linear low density polyethylene, 40g of ethylene-vinyl acetate copolymer, 30g of monoglyceride, 30g of polyethylene wax, 25g of silane coupling agent, 1.5g of antioxidant, and 20g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 450g of modified shell powder was added and mixed again for 30 minutes, after which the mixture was added to the twin screw extruder 100 from the side feed hopper, the mixed raw materials were kneaded, heated, extruded from the die head 130, pelletized and dried to obtain a bio-based composite material using a biological calcium-based biomass material.

[0056] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the twin-screw extruder's supply section 110 to the die head 130 were T1 = 170°C, T2 = 175°C, T3 = 175°C, T4 = 175°C, T5 = 175°C, T6 = 175°C, T7 = 170°C, and T8 = 170°C, and the temperature of the die head 130 was 176°C.

[0057] Example 3: Production of bio-based composite material using biological calcium-based biomass material 600 g of polypropylene, 15 g of linear low-density polyethylene, 30 g of ethylene-vinyl acetate copolymer, 25 g of monoglyceride, 20 g of polyethylene wax, 20 g of silane coupling agent, 1 g of antioxidant, and 20 g of polypropylene grafted maleic anhydride were added to a high-speed mixer and mixed for 30 minutes, after which 400 g of modified eggshell powder was added, and after mixing for another 30 minutes, the mixture was added to the twin-screw extruder 100 from the side feed hopper, kneaded and heated, extruded from the die head 130, pelletized and dried, and a bio-based composite material using a biological calcium-based biomass material was obtained.

[0058] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the twin-screw extruder's supply section 110 to the die head 130 were T1 = 170°C, T2 = 175°C, T3 = 175°C, T4 = 175°C, T5 = 175°C, T6 = 175°C, T7 = 170°C, and T8 = 170°C, and the temperature of the die head 130 was 176°C.

[0059] Example 4. Preparation of bio-based composites using cellulosic biomass materials 420 g of polypropylene, 30 g of linear low-density polyethylene, 50 g of ethylene-vinyl acetate copolymer, 30 g of monoglyceride, 20 g of polyethylene wax, 25 g of silane coupling agent, 2 g of antioxidant, and 20 g of polypropylene grafted maleic anhydride were added to a high-speed mixer and mixed for 30 minutes, after which 580 g of modified cellulose was added and mixed again for 30 minutes, after which the mixture was added to the twin-screw extruder 100 from the side feed hopper, and the mixed raw materials were kneaded, heated, and extruded from the die head 130, pelletized, and dried to obtain a bio-based composite material using cellulosic biomass material.

[0060] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 165°C, T2 = 165°C, T3 = 170°C, T4 = 170°C, T5 = 170°C, T6 = 170°C, T7 = 165°C, and T8 = 165°C, and the temperature of the die head 130 was 170°C.

[0061] Example 5: Preparation of a bio-based composite material using starch-based biomass material and biologically derived calcium-based biomass material 350g of polypropylene, 30g of linear low density polyethylene, 40g of ethylene-vinyl acetate copolymer, 20g of monoglyceride, 20g of polyethylene wax, 30g of silane coupling agent, 1g of antioxidant, and 30g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 400g of plasticized starch and 250g of modified shell powder were added, and after mixing for another 30 minutes, the mixture was added to the twin screw extruder 100 from the side feed hopper, kneaded and heated, extruded from the die head 130, pelletized and dried to obtain a bio-based composite material using a starch-based biomass material and a biologically derived calcium-based biomass material.

[0062] The temperature settings for the first section 120-1 to the eighth section 120-8, which make up the supply section 110 to the die head 130 of the twin-screw extruder 100, were T1 = 165°C, T2 = 170°C, T3 = 170°C, T4 = 175°C, T5 = 175°C, T6 = 170°C, T7 = 165°C, and T8 = 165°C, respectively, and the temperature of the die head 130 was 170°C.

[0063] Example 6. Preparation of bio-based composites using starch-based and cellulosic biomass materials 450 g of polypropylene, 25 g of linear low density polyethylene, 50 g of ethylene-vinyl acetate copolymer, 20 g of monoglyceride, 30 g of polyethylene wax, 30 g of silane coupling agent, 1.5 g of antioxidant, and 20 g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 400 g of plasticized starch and 150 g of modified cellulose were added and mixed again for 30 minutes before being added to the twin screw extruder 100 from the side feed hopper, the mixed raw materials were kneaded, heated, and extruded from the die head 130, pelletized and dried to obtain a bio-based composite material using a starch-based biomass material and a cellulose-based biomass material.

[0064] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 165°C, T2 = 165°C, T3 = 165°C, T4 = 170°C, T5 = 170°C, T6 = 170°C, T7 = 165°C, and T8 = 165°C, and the temperature of the die head 130 was 170°C.

[0065] Example 7: Preparation of a bio-based composite material using cellulosic biomass material and biological calcium biomass material 540 g of polypropylene, 10 g of linear low-density polyethylene, 30 g of ethylene-vinyl acetate copolymer, 20 g of monoglyceride, 30 g of polyethylene wax, 30 g of silane coupling agent, 1 g of antioxidant, and 30 g of polypropylene grafted maleic anhydride were added to a high-speed mixer and mixed for 30 minutes, after which 300 g of modified cellulose and 160 g of modified shell powder were added and mixed again for 30 minutes, after which the mixture was added to the twin-screw extruder 100 from the side feed hopper, and the mixed raw materials were kneaded, heated, and extruded from the die head 130, pelletized, and dried to obtain a bio-based composite material using a cellulose-based biomass material and a biologically derived calcium-based biomass material.

[0066] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 170°C, T2 = 170°C, T3 = 175°C, T4 = 175°C, T5 = 175°C, T6 = 170°C, T7 = 165°C, and T8 = 165°C, and the temperature of the die head 130 was 175°C.

[0067] Example 8: Preparation of bio-based composite materials using starch-based biomass materials, modified biological calcium-based biomass materials, and modified cellulose-based biomass materials 400g of polypropylene, 20g of linear low density polyethylene, 40g of ethylene-vinyl acetate copolymer, 20g of monoglyceride, 30g of polyethylene wax, 30g of silane coupling agent, 1g of antioxidant, and 20g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 300g of plasticized starch, 150g of modified shell powder, and 150g of modified cellulose were added and mixed again for 30 minutes, after which the mixture was added to the twin screw extruder 100 from the side feed hopper, the mixed raw materials were kneaded, heated, extruded from the die head 130, pelletized and dried to obtain a bio-based composite material using starch-based, biological calcium-based, and cellulose-based biomass materials.

[0068] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 165°C, T2 = 170°C, T3 = 175°C, T4 = 175°C, T5 = 175°C, T6 = 170°C, T7 = 170°C, and T8 = 165°C, and the temperature of the die head 130 was 175°C.

[0069] Example 9: Preparation of bio-based composite materials using starch-based biomass materials, modified biological calcium-based biomass materials, and modified cellulose-based biomass materials 450g of polypropylene, 20g of linear low density polyethylene, 40g of ethylene-vinyl acetate copolymer, 20g of monoglyceride, 30g of polyethylene wax, 30g of silane coupling agent, 1g of antioxidant, and 20g of polypropylene grafted maleic anhydride were added to a high speed mixer and mixed for 30 minutes, after which 300g of plasticized starch, 100g of modified eggshell powder, and 150g of modified cellulose were added and mixed again for 30 minutes, and then added to the twin screw extruder 100 from the side feed hopper, and the mixed raw materials were kneaded, heated, extruded from the die head 130, pelletized, and dried to obtain a bio-based composite material using starch-based, biological calcium-based, and cellulose-based biomass materials.

[0070] The temperature settings of each section from the first section 120-1 to the eighth section 120-8 constituting the supply section 110 to the die head 130 of the twin-screw extruder 100 were T1 = 165°C, T2 = 170°C, T3 = 175°C, T4 = 175°C, T5 = 175°C, T6 = 170°C, T7 = 170°C, and T8 = 165°C, and the temperature of the die head 130 was 175°C.

[0071] The bio-based composite materials produced in Examples 1 to 9 and petroleum-derived polypropylene (product name: Maoming Petrochemical PP040) were measured for their elongation at break, tensile strength, and elastic modulus according to ISO527-1:2019. The measurement results of the mechanical performance indexes of the bio-based composite materials and polypropylene according to each Example of the present invention are shown in Table 1. The mechanical performance indexes of the bio-based composite materials according to each Example of the present invention are similar to that of polypropylene. The biomass material content of Examples 1 to 9 of the present invention is 35.4% to 60.0%, while the biomass material content of polypropylene is 0. Table 1. Comparison of the characteristic indices of the bio-based composite materials according to the various embodiments of the present invention and polypropylene [Table 1]

[0072] Although several embodiments of the present invention have been described above, these embodiments are merely illustrative and do not limit the technical scope of the present invention. The present invention can take various other embodiments, and it is also possible to combine the configurations of the above-mentioned embodiments and the modified examples. Furthermore, various modifications such as omissions and substitutions can be made without departing from the gist of the present invention. These embodiments and their modifications are included in the scope and gist of the invention described in this specification, etc., and are included in the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0073] 100 Twin Screw Extruder 110 Supply section 120-1 to 120-8 Sections (of extruder 100) 130 Die Head 140 Screw

Claims

1. The present invention relates to a method for producing a cellulose fiber composite material, the cellulose fiber composite material comprising: 45 to 75 parts by weight of polypropylene; and 25 to 55 parts by weight of a biomass material, the biomass material being any one or a combination of two or three of plasticized starch, modified biogenic calcium, and modified cellulose; Further comprising 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of a silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of an antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier; Bio-based composites.

2. 2. The bio-based composite material of claim 1, wherein the weight percentage of the polypropylene in the bio-based composite material is between 40 and 60% and the weight percentage of the biomass material in the bio-based composite material is between 40 and 60%.

3. The bio-based composite material of claim 1 , wherein the bio-based composite material is formed into pellets.

4. 10. The bio-based composite material of claim 1, wherein the polypropylene is a homopolymer.

5. 2. The bio-based composite material of claim 1, wherein the plasticized starch is a mixture of starch, sodium aluminate, water, glycerin, and polyethylene glycol 400, and the weight ratio of starch, sodium aluminate, water, glycerin, and polyethylene glycol is 250:1-2:25-35:40-50:10-30.

6. 10. The bio-based composite material of claim 1, wherein the modified biogenic calcium comprises seashell powder or eggshell powder.

7. 2. The bio-based composite material of claim 1, wherein the modified cellulose is a mixture of wood pulp cellulose, an aluminate ester coupling agent, glycerin, and stearic acid, and the weight ratio of wood pulp cellulose, aluminate ester coupling agent, glycerin, and stearic acid is 30:1-3:2-4:0.3-0.

5.

8. 10. The bio-based composite material of claim 1, wherein the silane coupling agent is methyltrimethoxysilane.

9. 2. The bio-based composite material of claim 1, wherein the antioxidant is tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

10. Producing any one or two or three of a plasticized starch, a modified biogenic calcium, and a modified cellulose; A mixture is prepared by mixing 45 to 75 parts by weight of polypropylene, 1 to 3 parts by weight of linear low density polyethylene as a modifier, 3 to 5 parts by weight of ethylene-vinyl acetate copolymer as a modifier, 2 to 3 parts by weight of monoglyceride as a surfactant, 2 to 3 parts by weight of polyethylene wax as a modifier, 2 to 3 parts by weight of a silane coupling agent as a modifier, 0.1 to 0.2 parts by weight of an antioxidant, and 0 to 3 parts by weight of polypropylene grafted maleic anhydride as a modifier; Add 25 to 55 parts by weight of any one of the plasticized starch, the modified biological calcium, and the modified cellulose, or a combination of two or three of them, to the mixture and mix to produce a mixed raw material; The mixed raw material is kneaded, extruded, cut, pelletized and dried. Methods for producing bio-based composite materials.

11. 11. The method for producing a bio-based composite material according to claim 10, wherein the plasticized starch is produced by mixing starch, sodium aluminate and water, drying, then adding glycerin and polyethylene glycol 400, high speed mixing, drying and granulating, and the weight ratio of starch, sodium aluminate, water, glycerin and polyethylene glycol in the obtained plasticized starch is 250: 1-2: 25-35: 40-50: 10-30.

12. 11. The method of claim 10, wherein the modified biogenic calcium is produced by removing impurities from seashell or eggshell, washing it thoroughly with water, drying at 100°C, crushing and sieving to obtain 100 mesh seashell or eggshell powder, dissolving 1-3 parts by weight of caprolactam in absolute ethanol at 10% concentration, adding to 100 parts by weight of the 100 mesh seashell or eggshell powder and cold mixing, then mixing at 100°C to remove ethanol and drying.

13. 11. The method for producing a bio-based composite material according to claim 10, wherein the modified cellulose is obtained by obtaining wood pulp cellulose after dehydration and drying, adding an aluminate ester coupling agent and glycerin, mixing and stirring the mixture, and then adding and mixing stearic acid to obtain the modified wood pulp cellulose, and the weight ratio of the wood pulp cellulose, the aluminate ester coupling agent, the glycerin, and the stearic acid is 30:1 to 3:2 to 4:0.3 to 0.

5.

14. 11. The method for producing a bio-based composite material according to claim 10, wherein the mixed raw material obtained by mixing any one or two or three of the plasticized starch, the modified biological calcium, and the modified cellulose with the polypropylene, the linear low density polyethylene, the ethylene-vinyl acetate copolymer, the monoglyceride, the polyethylene wax, the silane coupling agent, the antioxidant, and the polypropylene grafted maleic anhydride is kneaded and heated in a kneading and heating step, the inlet to the outlet of the kneading and heating step are divided into first to eighth sections, the temperatures of the first to eighth sections are set in the ranges of 165 to 175°C, 165 to 170°C, 170 to 175°C, 170 to 175°C, 170 to 175°C, 165 to 170°C, 165 to 170°C, and 165 to 170°C, respectively, and the temperature of the outlet is set to 170 to 175°C.

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