Aging-resistant environment-friendly floor based on biomass modification and preparation method thereof

Abstract

The present application relates to the technical field of wood-plastic floor, and more particularly to an aging-resistant environment-friendly floor based on biomass modification and a preparation method thereof; the present application discloses an aging-resistant environment-friendly floor based on biomass modification and a preparation method thereof, which introduces a low-temperature solidifiable bio-based resin, i.e., bio-based benzoxazine, and forms a strong solidification layer by concentrating the low-temperature solidifiable bio-based benzoxazine resin on the surface layer of the floor, and the strong solidification layer is combined with an unmodified environment-friendly core layer, so that the shortcomings of poor water resistance, insufficient heat aging resistance and poor dimensional stability of the existing biomass-based environment-friendly floor are solved.

Description

Technical Field

[0001] This invention relates to the field of wood-plastic flooring technology, and more particularly to aging-resistant and environmentally friendly flooring based on biomass modification and its preparation method. Background Technology

[0002] With the popularization of green building concepts, the market demand for environmentally friendly flooring made from renewable resources is growing, and wood-plastic composite flooring, mainly composed of wood flour and polyethylene, is currently the mainstream trend. However, traditional wood-plastic flooring has several key performance shortcomings: First, due to the weak interfacial bonding between the hydrophilicity of wood flour and the hydrophobicity of polyethylene, the product has a high water absorption rate, making it prone to expansion, warping, and poor dimensional stability in humid environments. Second, the limited heat resistance of the polyethylene matrix leads to aging phenomena such as heat deformation, yellowing, and surface powdering in long-term use or under underfloor heating environments, limiting its service life. To solve these problems, inorganic fillers are usually added through physical blending or antioxidants are added to improve performance. However, this cannot fundamentally solve the problems of deep water resistance and heat aging caused by interfacial defects and insufficient matrix performance. Therefore, there is a need for an environmentally friendly flooring that achieves a balance between environmental friendliness, processability, and high performance, starting from the material itself. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing biomass-based environmentally friendly flooring, such as poor water resistance, insufficient heat aging resistance, and poor dimensional stability. This invention proposes a biomass-modified, aging-resistant environmentally friendly flooring and its preparation method. By introducing a low-temperature curable bio-based resin, namely bio-based benzoxazine, and concentrating this low-temperature curable bio-based benzoxazine resin on the flooring surface to form a strong curing layer, which is then combined with an unmodified environmentally friendly core layer, a significant improvement in flooring performance is achieved in a low-cost and highly compatible manner.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: an aging-resistant and environmentally friendly flooring based on biomass modification, which consists of an environmentally friendly substrate core layer and a highly effective cured surface layer from the inside out.

[0005] The preparation method of the aging-resistant and environmentally friendly flooring based on biomass modification includes the following steps: Step S1: Weigh the following raw materials in parts by weight: Environmentally friendly substrate core layer raw materials: 55-60 parts wood powder, 15-18 parts polyethylene, 12-15 parts quartz filler, 1-3 parts lubricant and 0.8-1 parts stabilizer; High-efficiency curing surface material: 25-30 parts wood flour, 6-8 parts polyethylene, 6-8 parts bio-based benzoxazine, 0.4-0.5 parts maleic anhydride grafted polyethylene, 1-3 parts lubricant and 0.8-1 parts stabilizer.

[0006] Step S2: Mix the environmentally friendly substrate core material and melt-blend it at 175°C using a twin-screw extruder, then extrude it to obtain the environmentally friendly substrate core. Simultaneously, mix the high-efficiency curing surface material and melt-blend it at 145°C using a twin-screw extruder, then extrude it onto the environmentally friendly substrate core to form a high-efficiency curing surface. Dry it in an oven at 110°C for 2 minutes, then hot-press it at 1.5MPa and 165°C for 1-1.5 minutes. After cooling, sanding, and polishing, the aging-resistant environmentally friendly flooring based on biomass modification is obtained.

[0007] Furthermore, the wood flour is 50 mesh; the polyethylene is from Daqing Petrochemical, with the grade PE-2426K; the quartz filler is 800 mesh; the lubricant is lubtop PE wax 613A; the stabilizer is from Walker, with the grade VOK-1130; and the maleic anhydride-grafted polyethylene is from Xingyuan Chemical, with the grade FR-100A.

[0008] The bio-based benzoxazine was prepared by the following steps: Step A1: Mix hydrochloric acid solution and furanylamine, stir for 15-20 min at a stirring rate of 120-150 rpm and a temperature of 2-5℃, then add levulinic acid, heat to 45-50℃, react for 24 h, cool to room temperature, wash with ethanol, centrifuge and filter to obtain filter cake, mix filter cake, sodium hydroxide and deionized water, stir for 30-40 min at a stirring rate of 300-400 rpm and a temperature of room temperature, extract with dichloromethane, take the aqueous layer and rotary evaporate, precipitate with hydrochloric acid solution, centrifuge and filter, dry to obtain carboxyfuran intermediate; Furthermore, in step A1: the ratio of hydrochloric acid solution, furfural, and levulinic acid is 18-20 mL: 7.2-7.3 g: 4.35-4.4 g; the ratio of filter cake, sodium hydroxide, and deionized water is 8.5-8.6 g: 90-100 mL: 3.2-3.3 g; and the mass fraction of hydrochloric acid solution is 37%.

[0009] Step A2: Mix lignin, ethanol and deionized water, stir at a stirring rate of 180-200 rpm and a temperature of 80°C, add paraformaldehyde and carboxyfuran intermediate, react for 12-14 h, cool to room temperature, rotary evaporate, centrifuge and filter, dry to obtain bio-based benzoxazine. Furthermore, in step A2, the ratio of lignin, ethanol, deionized water, paraformaldehyde, and carboxyfuran intermediate is 10-12g: 85-90mL: 35-40mL: 1.4-1.5g: 3.4-3.5g, the lignin phenolic hydroxyl content is 1.5mmol / g, and the paraformaldehyde mass fraction is 96%.

[0010] Furthermore, in the preparation process of the bio-based benzoxazine: furanylamine and levulinic acid react in hydrochloric acid solution to form an intermediate, which is then dechlorinated with sodium hydroxide to obtain a carboxyfuran intermediate. The benzoxazine structure is formed by reacting the aminofuran structure in the carboxyfuran intermediate, the phenolic hydroxyl structure in lignin, and paraformaldehyde, thus obtaining the bio-based benzoxazine. A detailed reaction diagram is attached to the instruction manual. Figure 1 .

[0011] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention discloses an aging-resistant and environmentally friendly flooring based on biomass modification and its preparation method. By introducing a low-temperature curable bio-based resin, namely bio-based benzoxazine, and by concentrating the low-temperature curable bio-based benzoxazine resin on the surface of the flooring to form a strong curing layer and an unmodified environmentally friendly core layer composite, the shortcomings of existing biomass-based environmentally friendly flooring, such as poor water resistance, insufficient heat aging resistance and poor dimensional stability, are solved.

[0012] The bio-based benzoxazine prepared in this invention is obtained by introducing benzoxazine groups into lignin as a substrate. Since the bio-based benzoxazine contains a large number of carboxyl groups, it can accelerate the ring-opening of the oxazine ring. At the same time, since there are unreacted phenolic hydroxyl groups in the lignin structure, the phenolic hydroxyl groups can interact with the cationic intermediates formed during the curing process of benzoxazine resin, which can accelerate the curing. The combined effect of these factors forms a self-catalytic effect, resulting in a significant decrease in the curing temperature of the bio-based benzoxazine. Meanwhile, because this invention adopts a core-surface layered design, by introducing a low-temperature curable bio-based benzoxazine into the high-efficiency curing surface layer, the surface layer can be completely cured at a low temperature of 165°C. At the same time, this temperature will not cause excessive softening and deformation of the polyethylene core layer, solving the process problem that high-performance thermosetting resins cannot be integrally molded with thermoplastic core layers. Furthermore, at the interface between the core layer and the surface layer, the surface layer resin can slightly penetrate into the micropores on the surface of the core layer under hot pressure, forming a mechanical anchor after curing. At the same time, it interacts with some of the hydroxyl groups on the surface of the wood powder, ensuring that the surface layer does not peel or fall off.

[0013] The method used in this invention, which employs a bio-based benzoxazine dense cross-linked network as the surface layer, results in a surface layer with extremely low water absorption, extremely high hardness, excellent heat resistance, and inherent resistance to ultraviolet free radicals. This provides the floor with a strong first line of defense, fundamentally solving the core problems of floor surface being prone to water absorption and swelling, poor heat resistance, and easy aging and yellowing, thus greatly improving the durability of the floor. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the reaction for preparing the bio-based benzoxazine of the present invention. Detailed Implementation

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with existing known technologies. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0016] In the following examples and comparative examples: the wood flour is 50 mesh; the polyethylene is from Daqing Petrochemical, grade PE-2426K; the quartz filler is 800 mesh; the lubricant is lubtop PE wax 613A; the stabilizer is from Walker, grade VOK-1130; and the maleic anhydride grafted polyethylene is from Xingyuan Chemical, grade FR-100A.

[0017] Example 1: A method for preparing an aging-resistant and environmentally friendly floor based on biomass modification, comprising the following steps: Step S1: Weigh the following raw materials in parts by weight: Environmentally friendly substrate core layer raw materials: 55 parts wood powder, 15 parts polyethylene, 12 parts quartz filler, 1 part lubricant and 0.8 parts stabilizer; High-efficiency curing surface material: 25 parts wood flour, 6 parts polyethylene, 6 parts bio-based benzoxazine, 0.4 parts maleic anhydride grafted polyethylene, 1 part lubricant and 0.8 parts stabilizer.

[0018] Step S2: Mix the environmentally friendly substrate core material and melt-blend it at 175°C using a twin-screw extruder, then extrude it to obtain the environmentally friendly substrate core. Simultaneously, mix the high-efficiency curing surface material and melt-blend it at 145°C using a twin-screw extruder, then extrude it onto the environmentally friendly substrate core to form a high-efficiency curing surface. Dry it in an oven at 110°C for 2 minutes, then hot-press it at 1.5MPa and 165°C for 1 minute. After cooling, grind and polish, obtain the biomass-modified aging-resistant environmentally friendly flooring.

[0019] The bio-based benzoxazine was prepared by the following steps: Step A1: Mix hydrochloric acid solution and furanylamine, stir for 15 min at a stirring rate of 120 rpm and a temperature of 5℃, then add levulinic acid, heat to 50℃, react for 24 h, cool to room temperature, wash with ethanol, centrifuge and filter to obtain filter cake, mix filter cake, sodium hydroxide and deionized water, stir for 40 min at a stirring rate of 300 rpm and a temperature of room temperature, extract with dichloromethane, take the aqueous layer and rotary evaporate, precipitate with hydrochloric acid solution, centrifuge and filter, dry to obtain carboxyfuran intermediate; Furthermore, in step A1: the ratio of hydrochloric acid solution, furanylamine, and levulinic acid is 20mL:7.2g:4.35g; the ratio of filter cake, sodium hydroxide, and deionized water is 8.5g:90mL:3.3g; and the mass fraction of hydrochloric acid solution is 37%.

[0020] Step A2: Mix lignin, ethanol and deionized water, stir at 200 rpm and 80°C, add paraformaldehyde and carboxyfuran intermediate, react for 12 h, cool to room temperature, rotary evaporate, centrifuge and filter, dry to obtain bio-based benzoxazine. Furthermore, in step A2, the ratio of lignin, ethanol, deionized water, paraformaldehyde, and carboxyfuran intermediate is 12g:85mL:35mL:1.5g:3.4g, the lignin phenolic hydroxyl content is 1.5mmol / g, and the paraformaldehyde mass fraction is 96%.

[0021] Example 2: A method for preparing aging-resistant and environmentally friendly flooring based on biomass modification, comprising the following steps: Step S1: Weigh the following raw materials in parts by weight: Environmentally friendly substrate core layer raw materials: 60 parts wood powder, 15 parts polyethylene, 15 parts quartz filler, 1 part lubricant and 1 part stabilizer; High-efficiency curing surface material: 25 parts wood flour, 6 parts polyethylene, 6 parts bio-based benzoxazine, 0.4 parts maleic anhydride grafted polyethylene, 1 part lubricant and 0.8 parts stabilizer.

[0022] Step S2: Mix the environmentally friendly substrate core material and melt-blend it at 175°C using a twin-screw extruder, then extrude it to obtain the environmentally friendly substrate core. Simultaneously, mix the high-efficiency curing surface material and melt-blend it at 145°C using a twin-screw extruder, then extrude it onto the environmentally friendly substrate core to form a high-efficiency curing surface. Dry it in an oven at 110°C for 2 minutes, then hot-press it at 1.5MPa and 165°C for 1.5 minutes. After cooling, sanding, and polishing, the aging-resistant environmentally friendly flooring based on biomass modification is obtained.

[0023] The bio-based benzoxazine was prepared by the following steps: Step A1: Mix hydrochloric acid solution and furanylamine, stir for 15 min at a stirring rate of 120 rpm and a temperature of 2℃, then add levulinic acid, heat to 45℃, react for 24 h, cool to room temperature, wash with ethanol, centrifuge and filter to obtain filter cake, mix filter cake, sodium hydroxide and deionized water, stir for 30 min at a stirring rate of 300 rpm and a temperature of room temperature, extract with dichloromethane, take the aqueous layer and rotary evaporate, precipitate with hydrochloric acid solution, centrifuge and filter, dry to obtain carboxyfuran intermediate; Furthermore, in step A1, the ratio of hydrochloric acid solution, furfural, and levulinic acid is 18 mL: 7.2 g: 4.35 g, the ratio of filter cake, sodium hydroxide, and deionized water is 8.5 g: 90 mL: 3.2 g, and the mass fraction of hydrochloric acid solution is 37%.

[0024] Step A2: Mix lignin, ethanol and deionized water, stir at 180 rpm and 80 ℃, add paraformaldehyde and carboxyfuran intermediate, react for 12 h, cool to room temperature, rotary evaporate, centrifuge and filter, dry to obtain bio-based benzoxazine. Furthermore, in step A2, the ratio of lignin, ethanol, deionized water, paraformaldehyde, and carboxyfuran intermediate is 10g:85mL:35mL:1.4g:3.4g, the lignin phenolic hydroxyl content is 1.5mmol / g, and the paraformaldehyde mass fraction is 96%.

[0025] Example 3: A method for preparing aging-resistant and environmentally friendly flooring based on biomass modification, which includes the following steps: Step S1: Weigh the following raw materials in parts by weight: Environmentally friendly substrate core layer raw materials: 60 parts wood powder, 18 parts polyethylene, 15 parts quartz filler, 3 parts lubricant and 1 part stabilizer; High-efficiency curing surface material: 30 parts wood powder, 8 parts polyethylene, 8 parts bio-based benzoxazine, 0.5 parts maleic anhydride grafted polyethylene, 3 parts lubricant and 1 part stabilizer.

[0026] Step S2: Mix the environmentally friendly substrate core material and melt-blend it at 175°C using a twin-screw extruder, then extrude it to obtain the environmentally friendly substrate core. Simultaneously, mix the high-efficiency curing surface material and melt-blend it at 145°C using a twin-screw extruder, then extrude it onto the environmentally friendly substrate core to form a high-efficiency curing surface. Dry it in an oven at 110°C for 2 minutes, then hot-press it at 1.5MPa and 165°C for 1.5 minutes. After cooling, sanding, and polishing, the aging-resistant environmentally friendly flooring based on biomass modification is obtained.

[0027] The bio-based benzoxazine was prepared by the following steps: Step A1: Mix hydrochloric acid solution and furanylamine, stir for 20 min at a stirring rate of 150 rpm and a temperature of 5℃, then add levulinic acid, heat to 50℃, react for 24 h, cool to room temperature, wash with ethanol, centrifuge and filter to obtain filter cake, mix filter cake, sodium hydroxide and deionized water, stir for 40 min at a stirring rate of 400 rpm and a temperature of room temperature, extract with dichloromethane, take the aqueous layer and rotary evaporate, precipitate with hydrochloric acid solution, centrifuge and filter, dry to obtain carboxyfuran intermediate; Furthermore, in step A1: the ratio of hydrochloric acid solution, furfural, and levulinic acid is 20 mL: 7.3 g: 4.4 g; the ratio of filter cake, sodium hydroxide, and deionized water is 8.6 g: 100 mL: 3.3 g; and the mass fraction of hydrochloric acid solution is 37%.

[0028] Step A2: Mix lignin, ethanol and deionized water, stir at 200 rpm and 80°C, add paraformaldehyde and carboxyfuran intermediate, react for 14 h, cool to room temperature, rotary evaporate, centrifuge and filter, dry to obtain bio-based benzoxazine. Furthermore, in step A2, the ratio of lignin, ethanol, deionized water, paraformaldehyde, and carboxyfuran intermediate is 12g:90mL:40mL:1.5g:3.5g, the lignin phenolic hydroxyl content is 1.5mmol / g, and the paraformaldehyde mass fraction is 96%.

[0029] Comparative Example 1: Compared with Example 3, this comparative example removes the bio-based benzoxazine from the high-efficiency curing surface material of Example 3, while the other steps are the same.

[0030] Comparative Example 2: Compared with Example 3, the bio-based benzoxazine in the strong curing surface material of Example 3 was replaced with bisphenol A type benzoxazine resin. The other steps were the same. The bisphenol A type benzoxazine resin was from Yuanyu Biotechnology Co., Ltd.

[0031] Comparative Example 3: Compared with Example 3, this comparative example directly blends the environmentally friendly substrate core material and the high-efficiency curing surface material of Example 3, and then performs the subsequent steps. Other steps are the same.

[0032] The environmentally friendly flooring prepared in Examples 1, 2, 3, Comparative Examples 1, 2, and 3 were tested against GB / T 17657-2022 for its peel resistance, UV yellowing resistance, boiling water resistance, and formaldehyde emission (per 1m³). 3 The results, obtained using the climate chamber method, are shown in the table below. Table 1 Test Results As shown in the table, the test results indicate that when comparing Examples 1, 2, and 3 with Comparative Examples 1, 2, and 3, the following results are observed: Comparative Example 1 removed the bio-based benzoxazine from the high-performance curing surface material of Example 3. Due to the lack of a high-performance surface layer barrier and reinforcement, water, light, and oxygen could easily penetrate and attack the wood flour and polyethylene in the core layer, resulting in a significant decrease in various properties. Comparative Example 2 replaced the bio-based benzoxazine in the high-performance curing surface material of Example 3 with bisphenol A type benzoxazine resin. Due to the mismatch in curing temperature, the surface resin could not be fully cured. The incompletely cured resin was a sticky or brittle weak solid, unable to form a strong bond with the core layer, and also unable to provide... High hardness leads to decreased peel resistance. The incompletely cross-linked network structure is loose, with numerous micropores and molecular chain ends, making it easier for water vapor and ultraviolet rays to penetrate, significantly weakening water and UV resistance. Comparative Example 3 directly blends the environmentally friendly substrate core material and the high-efficiency curing surface material from Example 3, abandoning the layered design, which leads to performance dilution and complicated interface problems. The small amount of bio-based benzoxazine is dispersed in the whole, failing to form a continuous and dense protective layer, resulting in limited improvement in water and UV resistance. At the same time, bio-based benzoxazine is also prone to forming a large number of micro-interfaces in the matrix, which may become stress concentration points, crack sources, and water vapor penetration channels, thus damaging the overall toughness and environmental resistance of the material.

[0033] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing aging-resistant and environmentally friendly flooring based on biomass modification, characterized in that: The process includes the following steps: Step S1: Weigh the following raw materials by weight: Environmentally friendly substrate core layer raw materials: 55-60 parts wood powder, 15-18 parts polyethylene, 12-15 parts quartz filler, 1-3 parts lubricant and 0.8-1 parts stabilizer; High-efficiency curing surface material: 25-30 parts wood flour, 6-8 parts polyethylene, 6-8 parts bio-based benzoxazine, 0.4-0.5 parts maleic anhydride grafted polyethylene, 1-3 parts lubricant and 0.8-1 parts stabilizer; Step S2: Mix the environmentally friendly substrate core material and melt-blend it at 175°C using a twin-screw extruder, then extrude it to obtain the environmentally friendly substrate core. Simultaneously, mix the high-efficiency curing surface material and melt-blend it at 145°C using a twin-screw extruder, then extrude it onto the environmentally friendly substrate core to form a high-efficiency curing surface. Dry it in an oven at 110°C for 2 minutes, then hot-press it at 1.5MPa and 165°C for 1-1.5 minutes. After cooling, sanding, and polishing, the aging-resistant environmentally friendly flooring based on biomass modification is obtained.

2. The method for preparing aging-resistant and environmentally friendly flooring based on biomass modification according to claim 1, characterized in that: The bio-based benzoxazine was prepared by the following steps: Step A1: Mix hydrochloric acid solution and furanylamine, stir for 15-20 min at a stirring rate of 120-150 rpm and a temperature of 2-5℃, then add levulinic acid, heat to 45-50℃, react for 24 h, cool to room temperature, wash with ethanol, centrifuge and filter to obtain filter cake, mix filter cake, sodium hydroxide and deionized water, stir for 30-40 min at a stirring rate of 300-400 rpm and a temperature of room temperature, extract with dichloromethane, take the aqueous layer and rotary evaporate, precipitate with hydrochloric acid solution, centrifuge and filter, dry to obtain carboxyfuran intermediate; Step A2: Mix lignin, ethanol and deionized water, stir at a speed of 180-200 rpm and a temperature of 80°C, add paraformaldehyde and carboxyfuran intermediate, react for 12-14 h, cool to room temperature, rotary evaporate, centrifuge and filter, dry to obtain bio-based benzoxazine.

3. The method for preparing aging-resistant and environmentally friendly flooring based on biomass modification according to claim 2, characterized in that: In step A1: the ratio of hydrochloric acid solution, furfural, and levulinic acid is 18-20 mL: 7.2-7.3 g: 4.35-4.4 g; the ratio of filter cake, sodium hydroxide, and deionized water is 8.5-8.6 g: 90-100 mL: 3.2-3.3 g; and the mass fraction of hydrochloric acid solution is 37%.

4. The method for preparing aging-resistant and environmentally friendly flooring based on biomass modification according to claim 2, characterized in that: In step A2, the ratio of lignin, ethanol, deionized water, paraformaldehyde, and carboxyfuran intermediate is 10-12g: 85-90mL: 35-40mL: 1.4-1.5g: 3.4-3.5g, the lignin phenolic hydroxyl content is 1.5mmol / g, and the mass fraction of paraformaldehyde is 96%.

5. The biomass-modified, aging-resistant, and environmentally friendly flooring prepared according to any one of claims 1-4, characterized in that: From the inside out, the layers consist of an environmentally friendly substrate core and a high-efficiency cured surface layer.

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