Environment-friendly decorative plate for whole house decoration and preparation method of environment-friendly decorative plate

Abstract

The invention discloses an environment-friendly decorative plate for whole house decoration and a preparation method of the environment-friendly decorative plate, belongs to the field of polymer composite materials, and aims to solve the problems of formaldehyde release, poor flame retardance, high density and the like of an existing decorative plate. Modified wood fibers, chopped basalt fibers, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass beads, a chain extender and zinc stearate are used as auxiliary materials. The decorative plate is prepared by mixing the components, performing melt blending and performing hot press molding. The prepared decorative plate is free of formaldehyde release, and has the advantages of light weight, high strength and long-acting flame retardance.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of polymer composites, and particularly relates to an environmentally friendly decorative panel for whole-house decoration and a preparation method thereof. BACKGROUND

[0002] Whole-house decoration is a popular trend in modern home decoration, which puts forward higher requirements for the performance of decorative panels. Not only excellent physical and mechanical properties are required, but also the needs of health and environmental protection and safety and fire prevention.

[0003] At present, the commonly used artificial panels (such as particle board and density board) on the market mostly use urea-formaldehyde resin or phenol-formaldehyde resin as adhesive. This kind of adhesive will continuously release free formaldehyde during production and use, causing serious pollution to indoor air and endangering human health. In addition, in order to meet the fireproof requirement, flame retardants are usually added to the panel. Traditional phosphorus-based flame retardants, such as ammonium polyphosphate (APP), have high flame retardant efficiency, but they are highly water-soluble and hygroscopic, and are easy to migrate and precipitate from the panel matrix in a humid environment, resulting in the decline of the flame retardant performance of the panel over time and affecting the surface decoration effect. In addition, the density of traditional decorative panels is generally large (usually greater than 1.0 g / cm 3 ), which brings many inconveniences to logistics transportation and on-site construction.

[0004] Therefore, how to develop a decorative panel with light weight, high strength, persistent flame retardancy and no formaldehyde release from the source is a technical problem to be solved in the field. SUMMARY

[0005] The present application aims to provide an environmentally friendly decorative panel for whole-house decoration and a preparation method thereof, which aims to solve the technical problems of existing decorative panels, such as formaldehyde release, easy migration and failure of flame retardants, and large density.

[0006] The purpose of the present application can be achieved by the following technical solutions: An environmentally friendly decorative panel for whole-house decoration, comprising the following raw materials in parts by mass: 45-50 parts of polylactic acid; 20-25 parts of polypropylene carbonate; 15-18 parts of modified wood fiber; 12-15 parts of chopped basalt fiber; 10-12 parts of microencapsulated ammonium polyphosphate; 3-4 parts of zinc borate; 0.5-1.0 parts of ferrocene; 10-12 parts of hollow glass microspheres; 0.3-0.5 parts of chain extender ADR-4370S; 0.8-1.2 parts of zinc stearate; The microencapsulated ammonium polyphosphate has a core-shell structure with a surface coated with melamine-phenylpropyl emulsion copolymer after pretreatment with silane coupling agent KH-550; The modified wood fiber is wood fiber treated with NDZ-201 titanate coupling agent.

[0007] Further, the microencapsulated ammonium polyphosphate is prepared by the following steps: The ammonium polyphosphate is dispersed in ethanol, and then the silane coupling agent KH-550 is added, and stirred at 60-65°C for 1-2 hours; then melamine and styrene-acrylic emulsion are added, and the system is heated to 80-90°C, and kept at this temperature for 2-4 hours; then the solid components are collected by filtration, and dried at 40-50°C until the weight is constant, to obtain the microencapsulated ammonium polyphosphate.

[0008] Further, the solid content of the styrene-acrylic emulsion is 40%.

[0009] Further, the ratio of the ammonium polyphosphate, ethanol, silane coupling agent KH-550, melamine and styrene-acrylic emulsion is 100 g:300 mL:5 g:15 g:20 g.

[0010] Further, the modified wood fiber is prepared by the following steps: The wood fiber and NDZ-201 titanate coupling agent are mixed in a high-speed mixer for 20-30 minutes to obtain the modified wood fiber.

[0011] Further, the length of the wood fiber is 100 μm.

[0012] Further, the ratio of the wood fiber and NDZ-201 titanate coupling agent is 100 g:3 g.

[0013] Further, the molecular weight of the polylactic acid is 100,000; the molecular weight of the polypropylene carbonate is 80,000; the length of the chopped basalt fiber is 3 mm; and the particle size of the hollow glass microsphere is 20 μm.

[0014] Further, the preparation method of the environmentally friendly decorative plate for whole house packaging comprises the following steps: The raw materials of polylactic acid, polypropylene carbonate, modified wood fiber, chopped basalt fiber, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass microsphere, chain extender ADR-4370S and zinc stearate are weighed according to the mass fraction, and then all the raw materials are put into a high-speed mixer and mixed for 15-30 minutes to obtain a mixture; the mixture is put into a twin-screw extruder for melt blending, and then cooled and granulated to obtain composite material particles; the composite material particles are put into a mold, preheated at 180-185°C for 3-5 minutes, and then hot-pressed at a pressure of 10 MPa for 10-12 minutes to obtain the environmentally friendly decorative plate.

[0015] Further, the temperature settings of the twin-screw extruder are: zone 1 160℃, zone 2 170℃, zone 3 175℃, and zone 4 170℃; and the screw rotation speed of the twin-screw extruder is set to 200-300 rpm.

[0016] The beneficial effects of the present application are: The environmentally friendly decorative plate for whole house decoration and the preparation method thereof provided by the present application solve the three core technical pain points in the field of existing decorative plates: environmental pollution, insufficient safety performance, and physical performance defects. Specifically, through innovative formula design and synergistic effect, the present application realizes the perfect combination of zero formaldehyde release, long-lasting flame retardancy, and lightweight high-strength mechanical properties. The specific analysis is as follows: (1) The formaldehyde pollution problem is fundamentally solved, and the environmental protection performance is excellent: The present application uses polylactic acid (PLA) and polypropylene carbonate (PPC) as the resin matrix of the composite material. Both of these materials are bio-based or biodegradable polymer materials, and their chemical structures and production processes do not involve formaldehyde. The present application completely abandons traditional formaldehyde-containing adhesives, fundamentally eliminates the source of formaldehyde, and makes the final decorative plate a green material that is completely friendly to human health and indoor environment, meeting the stringent requirements of modern whole house decoration for health and environmental protection.

[0017] (2) The flame retardant performance is efficient and long-lasting, and the safety of the product is significantly improved: The present application uses microencapsulated ammonium polyphosphate (APP) coated with melamine-phenyl emulsion copolymer after pretreatment with silane coupling agent KH-550. The core-shell structure of the microcapsule is like a dense "raincoat", effectively isolating APP from moisture, greatly reducing its water solubility and migration, and ensuring that the decorative plate still maintains excellent and stable flame retardant performance in long-term use or humid environment. The coating layer formed by the copolymer of melamine and phenyl emulsion is more dense and stable than the coating layer formed by single phenyl emulsion, which can more effectively protect APP, further highlighting the superiority of the specific microencapsulation scheme of the present application. At the same time, the present application compounding ferrocene as a synergistic flame retardant. Ferrocene has a significant synergistic flame retardant effect with microencapsulated APP and zinc borate, which can further improve the flame retardant efficiency of the material and achieve a higher safety level under the premise of ensuring the dosage.

[0018] (3) The unification of lightweight and high strength is realized, and the physical performance and application convenience of the product are optimized: The hollow glass microbeads are added as light functional fillers. The introduction of the hollow glass microbeads is a decisive factor for realizing the lightweight of the plate, effectively reducing the self-weight of the product, saving the transportation cost, and greatly reducing the difficulty of installation and construction. Meanwhile, the wood fibers are surface modified by using NDZ-201 titanate coupling agent. The titanate coupling agent successfully builds a "bridge" between the hydrophilic wood fibers and the hydrophobic PLA / PPC matrix, greatly improves the interfacial bonding force, enables the stress to be effectively transmitted, and thus the reinforcing effect of the wood fibers is fully exerted, so that the plate is endowed with excellent stiffness and strength. Finally, the chain extender effectively inhibits or repairs the thermal degradation of the PLA / PPC matrix during the melt processing, maintains a high molecular weight, and thus guarantees the toughness and strength of the composite matrix itself, which is another key guarantee for obtaining excellent mechanical properties.

[0019] In summary, the present application uses PLA / PPC bio-based resin as an environmentally friendly base, APP treated by a specific microencapsulation technology as a long-acting flame retardant core, compounds ferrocene and other synergistic agents, simultaneously uses surface modified wood fibers and basalt fibers for reinforcement, introduces a chain extender to guarantee the performance of the matrix, and uses hollow glass microbeads to realize lightweight, and finally obtains an environmentally friendly decorative plate which integrates absolute environmental protection, long-term safety, lightweight, high strength and other excellent properties. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application. Meanwhile, the raw materials, reagents or devices used in the following embodiments can be obtained from conventional commercial channels or can be obtained by existing known methods, if not otherwise specified.

[0021] Embodiment 1 Preparation of the environmentally friendly decorative plate for whole house decoration: Firstly, the above-mentioned environmentally friendly decorative plate comprises the following raw materials in parts by mass: 45 parts of polylactic acid (PLA, molecular weight 100,000, Zhejiang Haizheng Biology); 20 parts of polypropylene carbonate (PPC, molecular weight 80,000, Zibo Guangtong Chemical Industry); 15 parts of modified wood fiber; 12 parts of chopped basalt fiber (length 3 mm, Zhejiang Shijin Basalt); 10 parts of microencapsulated ammonium polyphosphate; Zinc borate (ZnB, industrial grade, Sinopharm Group) 3 parts; Ferrocene (electronic grade, Aldrich) 0.5 parts; Hollow glass microspheres (particle size 20 μm, 3M Company) 10 parts; Chain extender ADR-4370S (BASF) 0.3 parts; Zinc stearate (analytical pure, Shanghai Aldrin) 0.8 parts; Then, the preparation method of the above-mentioned environmentally friendly decorative plate comprises the following steps: S1, preparing microencapsulated ammonium polyphosphate: 100 g of ammonium polyphosphate is dispersed in 300 mL of ethanol, 5 g of silane coupling agent KH-550 is then added, stirring at 60°C for 1 h, after which 15 g of melamine and 20 g of benzene propyl emulsion (solid content 40%) are added, the system is heated to 80°C, and constant temperature reaction is carried out for 2 h, then the solid components are collected by filtration, and then placed in a constant temperature drying oven at 40°C until the weight is constant, to obtain microencapsulated ammonium polyphosphate.

[0022] S2, preparing modified wood fibers: 100 g of wood fibers (length 100 μm) and 3 g of NDZ-201 titanate coupling agent are placed in a high-speed mixer (800 rpm) and mixed for 20 min to obtain modified wood fibers.

[0023] S3, mixing and granulation: the above-mentioned raw materials (polylactic acid, polypropylene carbonate, modified wood fibers, chopped basalt fibers, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass microspheres, chain extender ADR-4370S and zinc stearate) are weighed according to the mass fraction, and then all the raw materials are placed in a high-speed mixer (1200 rpm) and mixed for 15 min, after which the mixture is obtained, and the mixture is placed in a twin-screw extruder for melt blending (the temperature of the twin-screw extruder is set as follows: zone 1 160°C, zone 2 170°C, zone 3 175°C, zone 4 170°C), wherein the screw speed of the twin-screw extruder is set to 200 rpm, after melt blending, the composite material particles are obtained after cooling and granulation.

[0024] S4, hot pressing: the composite material particles are placed in a mold, preheated at 180°C for 3 min, then hot pressed at 10 MPa for 10 min, and then cold pressed and demolded to obtain the environmentally friendly decorative plate.

[0025] Example 2 Preparation of environmentally friendly decorative plate for whole house installation: Firstly, the above-mentioned environmentally friendly decorative plate comprises the following raw materials according to the mass fraction: Polylactic acid (PLA, molecular weight 100,000, Zhejiang Haizheng Biology) 48 parts; Polypropylene carbonate (PPC, molecular weight 80,000, Zibo Guangtong Chemical) 22 parts; Modified wood fiber 17 parts; Chopped basalt fiber (length 3 mm, Zhejiang Shijin Basalt) 14 parts; Microencapsulated ammonium polyphosphate 12 parts; Zinc borate (ZnB, industrial grade, National Pharmaceutical Group) 4 parts; Ferrocene (electronic grade, Aldrich) 0.8 parts; Hollow glass microbeads (particle size 20 μm, 3M Company) 12 parts; Chain extender ADR-4370S (BASF) 0.5 parts; Zinc stearate (analytical pure, Shanghai Aldrin) 1.0 parts; Then, the preparation method of the above-mentioned environmentally friendly decorative plate comprises the following steps: S1, preparing microencapsulated ammonium polyphosphate: 100 g of ammonium polyphosphate is dispersed in 300 mL of ethanol, 5 g of silane coupling agent KH-550 is then added, stirring at 60°C for 2 h, then 15 g of melamine and 20 g of benzene propyl emulsion (solid content 40%) are added, the system is heated to 85°C, and constant temperature reaction is carried out for 4 h, then the solid components are collected by filtration, and then placed in a constant temperature drying oven at 40°C until the weight is constant, to obtain microencapsulated ammonium polyphosphate.

[0026] S2, preparing modified wood fiber: 100 g of wood fiber (length 100 μm) and 3 g of NDZ-201 titanate coupling agent are placed in a high-speed mixer (800 rpm) and mixed for 30 min to obtain modified wood fiber.

[0027] S3, mixing and granulation: the above-mentioned raw materials (polylactic acid, polypropylene carbonate, modified wood fiber, chopped basalt fiber, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass microbeads, chain extender ADR-4370S and zinc stearate) are weighed according to the mass fraction, and then all the raw materials are placed in a high-speed mixer (1200 rpm) and mixed for 30 min, then the mixture is obtained, and the mixture is placed in a twin-screw extruder for melt blending (the temperature of the twin-screw extruder is set as follows: zone 1 160°C, zone 2 170°C, zone 3 175°C, zone 4 170°C), wherein the screw rotation speed of the twin-screw extruder is set as 300 rpm, and after melt blending, the composite material particles are obtained after cooling and granulation.

[0028] S4, hot pressing: the composite material particles are placed in a mold, preheated at 180°C for 5 min, then hot pressed at a pressure of 10 MPa for 12 min, and then cold pressed and demolded to obtain the environmentally friendly decorative plate.

[0029] Example 3 Preparation of environmentally friendly decorative sheet for whole house packaging: Firstly, the above-mentioned environmentally friendly decorative sheet comprises the following raw materials in parts by mass: Poly lactic acid (PLA, molecular weight 100,000, Zhejiang Haizheng Biology) 50 parts; Polypropylene carbonate (PPC, molecular weight 80,000, Zibo Guangtong Chemical Industry) 25 parts; Modified wood fiber 18 parts; Chopped basalt fiber (length 3 mm, Zhejiang Shijin Basalt) 15 parts; Microencapsulated ammonium polyphosphate 12 parts; Zinc borate (ZnB, industrial grade, National Medicine Group) 4 parts; Ferrocene (electronic grade, Aladdin) 1.0 part; Hollow glass microbeads (particle size 20 μm, 3M Company) 12 parts; Chain extender ADR-4370S (BASF) 0.5 parts; Zinc stearate (analytical pure, Shanghai Aladdin) 1.2 parts; Then, the preparation method of the above-mentioned environmentally friendly decorative sheet comprises the following steps: S1, preparation of microencapsulated ammonium polyphosphate: 100 g of ammonium polyphosphate is dispersed in 300 mL of ethanol, 5 g of silane coupling agent KH-550 is added, stirring at 65℃ for 2 h, then 15 g of melamine and 20 g of benzyl lactate emulsion (solid content 40%) are added, the system is heated to 90℃, and constant temperature reaction is carried out for 4 h, then the solid components are collected by filtration, and then placed in a constant temperature dryer at 50℃ until the weight is constant, to obtain microencapsulated ammonium polyphosphate.

[0030] S2, preparation of modified wood fiber: 100 g of wood fiber (length 100 μm) and 3 g of NDZ-201 titanate coupling agent are placed in a high-speed mixer (800 rpm) and mixed for 30 min to obtain modified wood fiber.

[0031] S3, mixing and granulation: the above-mentioned raw materials (poly lactic acid, polypropylene carbonate, modified wood fiber, chopped basalt fiber, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass microbeads, chain extender ADR-4370S and zinc stearate) are weighed according to parts by mass, then all the raw materials are put into a high-speed mixer (1200 rpm) and mixed for 30 min, then the mixed material is obtained, and the mixed material is placed in a twin-screw extruder for melt blending (the temperature of the twin-screw extruder is set as follows: zone 1 160℃, zone 2 170℃, zone 3 175℃, zone 4 170℃), wherein the screw speed of the twin-screw extruder is set as 300 rpm, after melt blending, the composite material particles are obtained after cooling and granulation.

[0032] S4, hot-pressing: the composite particles were placed in a mold, preheated at 185℃ for 5 min, then hot-pressed at 10 MPa for 12 min, and finally demolded by cold-pressing to obtain the environmentally friendly decorative plate.

[0033] Comparative Example 1 Comparative Example 1 is a control group of Example 2, in which the raw material microencapsulated ammonium polyphosphate 12 parts in Example 2 is replaced by ammonium polyphosphate 12 parts, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained.

[0034] Comparative Example 2 Comparative Example 2 is a control group of Example 2, in which the raw material modified wood fiber 17 parts in Example 2 is replaced by wood fiber (length 100 μm) 17 parts, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained.

[0035] Comparative Example 3 Comparative Example 3 is a control group of Example 2, in which the raw material hollow glass microspheres (particle size 20 μm, 3M Company) 12 parts in Example 2 is removed, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained.

[0036] Comparative Example 4 Comparative Example 4 is a control group of Example 2, in which the raw material chain extender ADR-4370S (BASF) 0.5 parts in Example 2 is removed, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained.

[0037] Comparative Example 5 Comparative Example 5 is a control group of Example 2, in which the raw material ferrocene (electronic grade, Araldin) 0.8 parts in Example 2 is removed, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained.

[0038] Comparative Example 6 Comparative Example 6 is a control group of Example 2, in which the raw material melamine 15 g in S1 of Example 2 is removed, and the remaining raw materials, raw material amount and preparation steps remain consistent with Example 2. Finally, an environmentally friendly decorative plate is obtained, as follows: First, the above environmentally friendly decorative plate comprises the following raw materials by mass fraction: Polylactic acid (PLA, molecular weight 100,000, Zhejiang Haizheng Biology) 48 parts; Polypropylene carbonate (PPC, molecular weight 80,000, Zibo Guangtong Chemical Industry) 22 parts; Modified wood fiber 17 parts; Chopped basalt fiber (length 3 mm, Zhejiang Shijin basalt) 14 parts; Modified ammonium polyphosphate 12 parts; Zinc borate (ZnB, industrial grade, China National Pharmaceutical Group) 4 parts; Ferrocene (electronic grade, Aldrich) 0.8 parts; Hollow glass microspheres (particle size 20 μm, 3M Company) 12 parts; Chain extender ADR-4370S (BASF) 0.5 parts; Zinc stearate (analytical pure, Shanghai Aldrich) 1.0 parts; Then, the preparation method of the above-mentioned environmentally friendly decorative plate comprises the following steps: S1, preparing modified ammonium polyphosphate: 100 g of ammonium polyphosphate is dispersed in 300 mL of ethanol, 5 g of silane coupling agent KH-550 is then added, stirring at 60°C for 2 h, then 20 g of styrene-acrylic emulsion (solid content 40%) is added, the system is heated to 85°C, and constant temperature reaction is carried out for 4 h, then the solid component is collected by filtration, and then placed in a constant temperature drying oven at 40°C until the weight is constant, to obtain the modified ammonium polyphosphate.

[0039] S2, preparing modified wood fiber: 100 g of wood fiber (length 100 μm) and 3 g of NDZ-201 titanate coupling agent are placed in a high-speed mixer (800 rpm) and mixed for 30 min to obtain the modified wood fiber.

[0040] S3, mixing and granulation: the above-mentioned raw materials (polylactic acid, polypropylene carbonate, modified wood fiber, chopped basalt fiber, modified ammonium polyphosphate, zinc borate, ferrocene, hollow glass microspheres, chain extender ADR-4370S and zinc stearate) are weighed according to the mass fraction, and then all the raw materials are placed in a high-speed mixer (1200 rpm) and mixed for 30 min, then the mixture is obtained, and the mixture is placed in a twin-screw extruder for melt blending (the temperature of the twin-screw extruder is set as follows: zone 1 160°C, zone 2 170°C, zone 3 175°C, zone 4 170°C), wherein the screw rotation speed of the twin-screw extruder is set as 300 rpm, and after melt blending, the composite material particles are obtained after cooling and granulation.

[0041] S4, hot pressing: the composite material particles are placed in a mold, preheated at 180°C for 5 min, then hot pressed at 10 MPa for 12 min, and then cold pressed and demolded to obtain the environmentally friendly decorative plate.

[0042] Test Example 1 The environmentally friendly decorative board prepared from Example 1 to Example 3 and Comparative Example 1 to Comparative Example 6 was subjected to performance testing, and the performance testing process was as follows, and the test results are shown in Table 1: (1) Density test: According to GB / T 1033.1-2008 standard, the density of the sample was tested by density balance method.

[0043] (2) Mechanical property test: A. Bending strength: According to GB / T 9341-2008 standard, three-point bending test was carried out on a universal material testing machine.

[0044] B. Tensile strength: According to GB / T 1040.2-2006 standard, the board was made into a standard dumbbell-shaped sample, and tensile test was carried out on a universal material testing machine.

[0045] (3) Flame retardant performance test: A. Limiting oxygen index (LOI): According to GB / T 2406.2-2009 standard, test was carried out on an oxygen index tester.

[0046] B. Vertical burning grade: Test was carried out according to GB / T 2408-2008 (equivalent to UL-94) standard.

[0047] (4) Flame retardant performance durability test (water resistance): The sample was completely immersed in boiling water for 24 hours. After taking out, it was dried to constant weight in an oven at 60°C, and then the limiting oxygen index (LOI) was retested. By comparing the change of LOI before and after boiling water treatment, the anti-migration ability of the flame retardant was evaluated.

[0048] (5) Formaldehyde emission test: According to the dryer method in GB 18580-2017 "Indoor decoration and decoration materials - Formaldehyde emission limit of artificial board and its products".

[0049] Table 1 Test results Data analysis from Table 1: 1. Formaldehyde emission analysis: Results: The formaldehyde emission of all examples (1-3) and comparative examples (1-6) was "not detected".

[0050] Analysis: Because the base material used in the present application is polylactic acid (PLA) and polypropylene carbonate (PPC), it completely replaces the urea-formaldehyde resin or phenol-formaldehyde resin adhesive that will release formaldehyde in traditional artificial board. Therefore, the source of formaldehyde is fundamentally eliminated. This result verifies the basic advantage of the present application in environmental protection.

[0051] 2. Flame Retardant Performance and Durability Analysis: Comparison: Example 2 vs. Comparative Example 1 (unmicroencapsulated APP) vs. Comparative Example 5 (without ferrocene) vs. Comparative Example 6 (microcapsule wall material lacks melamine).

[0052] Analysis: (1) Necessity of Microencapsulation (Example 2 vs. Comparative Example 1): Initial Flame Retardancy: The initial limiting oxygen index (LOI) and vertical burning rating (V-0) of both are very close, indicating that in the initial state, APP provides excellent flame retardant effect whether it is microencapsulated or not.

[0053] Flame Retardant Durability (Key Difference): After 24 hours of boiling water treatment, the LOI of Example 2 only decreases from 34.2% to 33.9%, with a negligible change. However, the LOI of Comparative Example 1 (using untreated APP) decreases sharply from 33.8% to 19.5%. This shows that untreated APP, due to its water solubility and hygroscopicity, migrates and loses a large amount during the boiling water treatment process, resulting in almost complete loss of flame retardant performance of the board. On the contrary, the microcapsule structure in Example 2 effectively protects APP, greatly improves its water resistance and anti-migration ability, and ensures the long-term and durable flame retardant performance. This is one of the core advantages of the invention.

[0054] (2) Role of Synergistic Flame Retardant (Example 2 vs. Comparative Example 5): After removing ferrocene in Comparative Example 5, its LOI (29.5%) is significantly lower than that of Example 2 (34.2%), and the vertical burning rating decreases from V-0 to V-1. This proves that ferrocene, as a synergistic flame retardant, has a significant synergistic effect with ammonium polyphosphate and zinc borate system, effectively improving the flame retardant efficiency of the material.

[0055] (3) Role of Microcapsule Wall Material Integrity (Example 2 vs. Comparative Example 6): Comparative Example 6 removes melamine during the preparation of microcapsules and only uses a phenolic emulsion for coating. Its initial LOI (32.1%) is slightly lower than that of Example 2 (34.2%), but the key is that after boiling water treatment, its LOI decreases significantly from 32.1% to 28.6%. Although the decrease is not as dramatic as Comparative Example 1, it is still significantly inferior to Example 2. This shows that the coating layer formed by the copolymerization of melamine and phenolic emulsion is more dense and stable than the coating layer formed by the use of phenolic emulsion alone, which can more effectively prevent water erosion and APP migration.

[0056] 3. Mechanical Property Analysis: Comparison: Example 2 vs. Comparative Example 2 (unmodified wood fiber) vs. Comparative Example 4 (without chain extender).

[0057] Analysis: (1) The necessity of wood fiber modification (Example 2 vs. Comparative Example 2): After using unmodified wood fiber in Comparative Example 2, its flexural strength (25.1 MPa) and tensile strength (16.8 MPa) decreased by about 50% compared with Example 2 (flexural 48.5 MPa, tensile 32.6 MPa). This is because the wood fiber surface contains a large number of hydrophilic hydroxyl groups, which are poorly compatible with the hydrophobic PLA / PPC resin matrix, resulting in very weak interfacial bonding. Stress cannot be effectively transferred from the matrix to the reinforcing fibers, and the fibers act as defects rather than reinforcements. However, Example 2 uses titanate coupling agent to modify the wood fiber, and the coupling agent molecules act as a "bridge", one end of which is combined with the fiber surface and the other end is entangled with the resin matrix, greatly improving the interfacial compatibility, thereby significantly improving the mechanical properties.

[0058] (2) The necessity of chain extender (Example 2 vs. Comparative Example 4): After removing the chain extender ADR-4370S in Comparative Example 4, its flexural strength (21.5 MPa) and tensile strength (14.2 MPa) decreased by more than 50% compared with Example 2 (flexural 48.5 MPa, tensile 32.6 MPa), and the performance deteriorated very seriously. This shows that the chain extender plays a crucial role in the system. During melt blending, PLA and PPC may undergo some degree of thermal degradation, resulting in chain scission and a decrease in molecular weight. The chain extender can react with the broken chain ends (-OH, -COOH) to reconnect them, effectively inhibiting or repairing degradation, and increasing the molecular weight and melt strength of the entire polymer matrix, thereby fundamentally ensuring the excellent mechanical properties of the composite material.

[0059] 4. Density analysis: Comparison: Example 2 vs. Comparative Example 3 (without hollow glass microspheres).

[0060] Analysis: The density of Example 2 is 0.96 g / cm 3 , and the density of Comparative Example 3 increases to 1.18 g / cm 3 after removing the hollow glass microspheres. This clearly proves that the introduction of hollow glass microspheres is a key factor in achieving lightweight boards. The hollow structure provides volume while hardly increasing weight, effectively reducing the overall density of the composite material and achieving the purpose of lightweight.

[0061] 5. Internal comparison analysis of Examples 1-3: Trend: From Example 1 to Example 3, the amount of each component (such as PLA, PPC, fiber, flame retardant, etc.) gradually increases within the range defined in the claims, tending towards the upper limit.

[0062] Performance changes: Mechanical properties: flexural strength (45.2→48.5→51.3 MPa) and tensile strength (30.1→32.6→34.8 MPa) steadily increase. This is mainly due to the increase in the content of reinforcing phases (modified wood fiber, basalt fiber) and the optimization of the mechanical properties of the matrix by the higher content of chain extender.

[0063] Flame retardant performance: limiting oxygen index (33.5→34.2→35.1%) also increases, which is directly related to the increase in the content of flame retardants (microcapsule APP, zinc borate, ferrocene).

[0064] Density: the density (0.98→0.96→0.95 g / cm 3 ) decreases slightly, which may be because in the formulation with increased total mass, the relative volume fraction of lightweight filler (hollow glass microbeads) is more prominent.

[0065] Summary: (1) Environmental protection: by using PLA / PPC bio-based resin, the present application successfully solves the problem of formaldehyde release from traditional wood-based panels from the source.

[0066] (2) Long-term flame retardancy: by microencapsulating APP (especially using melamine-phenylpropyl emulsion copolymer coating) and compounding ferrocene and other synergistic flame retardants, the present application not only achieves excellent V-0 level flame retardant performance, but more importantly, successfully solves the technical pain points of easy migration and failure of traditional phosphorus-based flame retardants, ensuring the durability and stability of the flame retardant performance.

[0067] (3) Excellent mechanical properties: by surface modification of wood fiber and addition of chain extender, the present application effectively improves the compatibility of fillers and matrix, and enhances the toughness and strength of the matrix itself, thereby achieving mechanical properties far superior to unmodified / unadded systems.

[0068] (4) Lightweight: by introducing hollow glass microbeads, the present application significantly reduces the density of the panel, achieving the goal of lightweight and high strength, and solving the problem of traditional heavy panels.

[0069] It should be noted that in this text, terms such as "include, contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent elements of such process, method, article or device.

[0070] While embodiments of the application have been shown and described, it is to be understood that the application is not limited to the details of the embodiments described, since numerous changes, modifications, substitutions and alterations can be made thereto without departing from the spirit and scope of the application as defined by the appended claims and their equivalents.

Claims

1. An environmentally friendly decorative sheet material for whole house finishing, characterized by, By mass parts, including the following raw materials: polylactic acid 45-50 parts; polypropylene carbonate 20-25 parts; modified wood fiber 15-18 parts; chopped basalt fiber 12-15 parts; microencapsulated ammonium polyphosphate 10-12 parts; zinc borate 3-4 parts; ferrocene 0.5-1.0 parts; hollow glass microspheres 10-12 parts; chain extender ADR-4370S 0.3-0.5 parts; zinc stearate 0.8-1.2 parts; The microencapsulated ammonium polyphosphate is a core-shell structure coated with melamine-phenylpropyl emulsion copolymer after pretreatment with silane coupling agent KH-550. The modified wood fiber is a wood fiber treated with NDZ-201 titanate coupling agent.

2. An environmentally friendly decorative sheet material for whole house finishing according to claim 1, wherein The microencapsulated ammonium polyphosphate is prepared by the following steps: Disperse ammonium polyphosphate in ethanol, then add silane coupling agent KH-550, stir at 60-65℃ for 1-2h, then add melamine and phenylpropyl emulsion, heat the system to 80-90℃, and keep the temperature for 2-4h, then collect the solid components by filtration, and dry at 40-50℃ until constant weight to obtain the microencapsulated ammonium polyphosphate.

3. A green decorative sheet for whole house finishing according to claim 2, wherein The solid content of the phenylpropyl emulsion is 40%.

4. A green decorative sheet for whole house finishing according to claim 2, wherein The amount ratio of the ammonium polyphosphate, ethanol, silane coupling agent KH-550, melamine and phenylpropyl emulsion is 100g:300mL:5g:15g:20g.

5. The environmentally friendly decorative sheet material for whole house finishing according to claim 1, wherein The modified wood fiber is prepared by the following steps: Mix the wood fiber and NDZ-201 titanate coupling agent in a high-speed mixer for 20-30min to obtain the modified wood fiber.

6. A green decorative sheet for whole house finishing according to claim 5, wherein The length of the wood fiber is 100μm.

7. A green decorative sheet for whole house finishing according to claim 5, wherein The amount ratio of the wood fiber and NDZ-201 titanate coupling agent is 100g:3g.

8. A green decorative sheet for whole house finishing according to claim 1, wherein The molecular weight of the polylactic acid is 100,000; the molecular weight of the polypropylene carbonate is 80,000; the length of the chopped basalt fiber is 3mm; and the particle size of the hollow glass microspheres is 20μm.

9. The method for preparing an environmentally friendly decorative sheet for a whole house according to any one of claims 1 to 8, wherein Including the following steps: Weigh the raw materials polylactic acid, polypropylene carbonate, modified wood fiber, chopped basalt fiber, microencapsulated ammonium polyphosphate, zinc borate, ferrocene, hollow glass microspheres, chain extender ADR-4370S and zinc stearate by mass parts, then mix all the raw materials in a high-speed mixer for 15-30min to obtain a mixture, melt blend the mixture in a twin-screw extruder, then cool, pelletize, and obtain composite particles, preheat the composite particles in a mold at 180-185℃ for 3-5min, then hot-press at 10MPa for 10-12min, and then cold-press and demold to obtain an environmentally friendly decorative panel.

10. The method for preparing an environmentally friendly decorative sheet for a whole house according to claim 9, wherein The temperature of the twin-screw extruder is set as follows: zone 1 160℃, zone 2 170℃, zone 3 175℃, and zone 4 170℃; and the screw speed of the twin-screw extruder is set as 200-300rpm.

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