PVC wood-plastic material with strong smoke suppression and flame retardance and preparation method of PVC wood-plastic material

Abstract

The invention provides a strong smoke suppression flame retardant PVC wood-plastic material and a preparation method thereof, and relates to the technical field of wood-plastic composites, the PVC wood-plastic material comprises the following components by weight: 70-100 parts of PVC resin, 20-30 parts of wood flour, 20-30 parts of calcium carbonate, 15-20 parts of a smoke suppression material, 10-15 parts of a flame retardant, 1-6 parts of a foaming agent, 5-10 parts of a stabilizer, 1-2 parts of a coupling agent, 5-10 parts of a processing aid, and 1-4 parts of a lubricant; wherein the smoke suppression material comprises a molybdenum compound, ferrocene and oxalate dihydrate in a mass ratio of 1: (0.5-1.5): (5-10); the preparation method comprises the steps of wood powder end-capping modification and PVC wood-plastic material preparation. The PVC wood-plastic material prepared by the invention has excellent flame retardant property and smoke suppression property.

Description

Technical Field

[0001] The invention relates to the technical field of wood-plastic composite materials, and in particular to a highly smoke-suppressing and flame-retardant PVC wood-plastic material and a preparation method thereof. Background Art

[0002] Wood-plastic composite profiles are a new type of composite material that has been booming in recent years at home and abroad. They refer to the use of polyethylene, polypropylene and polyvinyl chloride, etc., instead of the usual resin adhesives, mixed with waste plant fibers such as wood powder, rice husks, straw to form new wood materials, and then produced through plastic processing processes such as extrusion, molding, and injection molding. The boards or profiles are mainly used in building materials, furniture, logistics packaging and other industries. The boards formed by hot extrusion after mixing plastic and wood powder in a certain proportion are called extruded wood-plastic composite boards. PVC wood-plastic material is the main type of wood-plastic composite material, that is, a composite material formed by melt blending of polyvinyl chloride (PVC) and plant fiber materials (usually wood powder). It is green and environmentally friendly, and has the excellent characteristics of both wood and plastic.

[0003] PVC wood-plastic materials have outstanding advantages such as waterproof and moisture-proof, anti-corrosion and anti-insect, and excellent mechanical properties. In the early stages of production and application, it was generally believed that by using a plastic matrix to wrap wood powder filler, even if no flame retardant was added to the composite material, the flame retardancy of the plastic matrix itself could prevent the attack of flames and provide sufficient flame retardancy for the material. However, when the temperature rises further, the plastic matrix decomposes and becomes the first material to smoke. The plastic matrix first undergoes a dehydrochlorination reaction, followed by a series of reactions such as cross-linking, cyclization, and chain breaking, ultimately generating carbon monoxide, carbon dioxide, benzene ring compounds, and carbon smoke. The existing solution is usually to add flame retardants to the PVC wood-plastic material system. However, the smoke suppression effect of flame retardants is limited and still poses a threat to the lives of residents.

[0004] Based on this, the present invention discloses a highly smoke-suppressing and flame-retardant PVC wood-plastic material and a preparation method thereof. The material not only has excellent flame-retardant properties, but also has outstanding smoke-suppressing properties, and its safety of use is greatly improved. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the present invention provides a highly smoke-suppressing and flame-retardant PVC wood-plastic material and a preparation method thereof, which solves the technical problem that the existing PVC wood-plastic material has poor smoke-suppressing performance.

[0007] (II) Technical solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] The highly smoke-suppressing and flame-retardant PVC wood-plastic material comprises the following components in parts by weight: 70-100 parts of PVC resin, 20-30 parts of wood powder, 20-30 parts of calcium carbonate, 15-20 parts of smoke-suppressing material, 10-15 parts of flame retardant, 1-6 parts of foaming agent, 5-10 parts of stabilizer, 1-2 parts of coupling agent, 5-10 parts of processing aid, and 1-4 parts of lubricant; wherein the smoke-suppressing material comprises a molybdenum compound, ferrocene, and dihydrate oxalate in a mass ratio of 1: (0.5-1.5): (5-10).

[0010] Preferably, the molybdenum compound is any one of ammonium octamolybdate, molybdenum trioxide, octamolybdate trimethyleneamine, and ammonium phosphomolybdate; the dihydrate oxalate is any one of manganese oxalate dihydrate, ferrous oxalate dihydrate, cobalt oxalate dihydrate, nickel oxalate dihydrate, and copper oxalate dihydrate.

[0011] Preferably, the smoke suppression material comprises ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:(0.5-1):(5-8).

[0012] Preferably, the flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate in a mass ratio of 1:(2.5-5):(0.1-1):(1-4).

[0013] Preferably, 10-20 parts of ABS resin are also included.

[0014] Preferably, the foaming agent is one or a mixture of azodicarbonamide and calcium bicarbonate.

[0015] Preferably, the stabilizer is any one of a calcium zinc stabilizer, a zeolite, and a silica gel.

[0016] Preferably, the coupling agent is titanate or aluminate.

[0017] The preparation method of the strong smoke suppression and flame retardant PVC wood-plastic material specifically comprises the following steps:

[0018] S1. Wood powder end-capping modification:

[0019] Weigh wood powder and add it to 8%wt triethoxysilane;

[0020] Then add vinyl tri(β-methoxyethoxy)silane until the liquid level completely covers the wood powder;

[0021] After standing for 2 to 3 days, the mixed solution of vinyl tri(β-methoxyethoxy)silane and triethoxysilane was removed, and the mixture was washed with anhydrous ethanol for 4 to 6 times;

[0022] The wood powder obtained by filtration is heated in a water bath at a temperature of 30 to 50° C. for 1 to 2 hours, and then dried to obtain modified wood powder;

[0023] S2.PVC wood plastic material preparation:

[0024] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder, calcium carbonate, smoke suppression material, and flame retardant, and mix the above components evenly;

[0025] Then, a foaming agent, a stabilizer, a coupling agent, a processing aid, and a lubricant are added to the mixed system, and stirred to react;

[0026] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

[0027] Preferably, in S2, the ABS resin is first heated to a molten state, and then the PVC resin is added. After the two are stirred and melted evenly, the temperature is lowered and then wood powder, calcium carbonate, smoke suppression material and flame retardant are added.

[0028] (III) Beneficial effects

[0029] The present invention provides a highly smoke-suppressing and flame-retardant PVC wood-plastic material and a preparation method thereof. Compared with the prior art, the present invention has the following beneficial effects:

[0030] 1. The smoke suppression material is added to the PVC wood-plastic material system disclosed in the present invention. The smoke suppression material is a composition of a molybdenum compound, ferrocene and dihydrated oxalate. The molybdenum compound mainly plays a role in the PVC wood-plastic solid phase material, and promotes the formation of a carbon layer and reduces the amount of smoke through Lewis acid. That is to say, at the beginning of combustion, the molybdenum compound can produce a smoke suppression effect; ferrocene in the chlorine-containing PVC system mainly plays a smoke suppression role in the condensed phase. When the combustion proceeds to a certain extent (usually the middle stage), that is, when a certain amount of gas is generated, ferrocene can play a role to the maximum extent, avoiding the problem of a decrease in the smoke suppression effect of the PVC wood-plastic material in the middle stage of combustion; dihydrated oxalate itself produces a smoke suppression effect by cross-linking with PVC and promoting the formation of a carbon layer. At the same time, in the smoke suppression process, it can synergize with the molybdenum compound and dihydrated oxalate to play a smoke suppression and synergistic role.

[0031] 2. Before preparing the PVC wood-plastic material, the present invention first uses two silane coupling agents to end-cap and modify the wood powder. The two silane coupling agents cooperate with each other to improve the flame retardancy of the wood powder, the interface bonding strength with organic matter and the stability of the system. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The embodiments of the present application provide a highly smoke-suppressing and flame-retardant PVC wood-plastic material and a preparation method thereof, thereby solving the technical problem that the existing PVC wood-plastic material has poor smoke suppression performance. The prepared PVC wood-plastic material not only has excellent flame retardant properties, but also has outstanding smoke suppression performance, and its safety of use is greatly improved.

[0034] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with specific implementation methods.

[0035] All raw materials of the present invention are purchased from cooperative manufacturers.

[0036] Embodiment 1:

[0037] Strong smoke suppression and flame retardant PVC wood-plastic material, including the following components in parts by weight: 70 parts of PVC resin, 20 parts of wood powder, 20 parts of calcium carbonate, 15 parts of smoke suppression material, 10 parts of flame retardant, 1 part of azodicarbonamide, 5 parts of zeolite, 1 part of titanate, 5 parts of processing aid, and 1 part of silicone oil;

[0038] The smoke suppression material includes ammonium octamolybdate, ferrocene, and manganese oxalate dihydrate in a mass ratio of 1:0.5:5;

[0039] The flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate in a mass ratio of 1:2.5:0.1:1.

[0040] The preparation method of the strong smoke suppression and flame retardant PVC wood-plastic material specifically comprises the following steps:

[0041] S1. Wood powder end-capping modification:

[0042] Weigh wood powder and add it to 8%wt vinyltriethoxysilane;

[0043] Then add vinyl tri(β-methoxyethoxy)silane until the liquid level completely covers the wood powder;

[0044] After standing for 3 days, the mixed solution of vinyl tri(β-methoxyethoxy) silane and vinyl triethoxy silane was removed and washed with anhydrous ethanol for 4 times;

[0045] The wood powder obtained by filtration was heated in a water bath at a temperature of 30°C for 2 hours, and then dried to obtain modified wood powder;

[0046] S2.PVC wood plastic material preparation:

[0047] The modified wood powder is sieved and placed in an oven to dry for 8 hours. The PVC resin is first heated to a molten state, and then the wood powder, calcium carbonate, smoke suppression material, and flame retardant are added after stirring evenly. The above components are first mixed evenly;

[0048] Then, azodicarbonamide, zeolite, titanate, processing aid and silicone oil are added to the mixed system, and stirred to react;

[0049] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

[0050] Embodiment 2:

[0051] Strong smoke suppression and flame retardant PVC wood-plastic material, including the following components in parts by weight: 90 parts of PVC resin, 25 parts of wood powder, 25 parts of calcium carbonate, 18 parts of smoke suppression material, 12 parts of flame retardant, 3 parts of calcium bicarbonate, 7 parts of calcium zinc stabilizer, 1.5 parts of aluminate, 7 parts of processing aid, and 3 parts of silicone oil;

[0052] The smoke suppression material includes ammonium phosphomolybdate, ferrocene, and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6;

[0053] The flame retardant includes ammonium polyphosphate, aluminum hydroxide, zinc borate, and melamine cyanurate in a mass ratio of 1:3.5:0.5:3;

[0054] The preparation method of the strong smoke suppression and flame retardant PVC wood-plastic material specifically comprises the following steps:

[0055] S1. Wood powder end-capping modification:

[0056] Weigh wood powder and add it to 8%wt vinyltriethoxysilane;

[0057] Then add vinyl tri(β-methoxyethoxy)silane until the liquid level completely covers the wood powder;

[0058] After standing for 3 days, the mixed solution of vinyl tri(β-methoxyethoxy)silane and vinyl triethoxysilane was removed and washed with anhydrous ethanol for 5 times;

[0059] The wood powder obtained by filtration was heated in a water bath at a temperature of 40°C for 1 hour, and then dried to obtain modified wood powder;

[0060] S2.PVC wood plastic material preparation:

[0061] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder, calcium carbonate, smoke suppression material, and flame retardant, and mix the above components evenly;

[0062] Then, calcium bicarbonate, calcium zinc stabilizer, aluminate, processing aid and silicone oil are added to the mixed system, and stirred to react;

[0063] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

[0064] Example 3

[0065] The strong smoke suppression and flame retardant PVC wood-plastic material comprises the following components in parts by weight: 100 parts of PVC resin, 30 parts of wood powder, 30 parts of calcium carbonate, 20 parts of smoke suppression material, 15 parts of flame retardant, 6 parts of calcium bicarbonate, 10 parts of silica gel, 2 parts of titanate, 10 parts of processing aid, and 4 parts of silicone oil;

[0066] The smoke suppression material includes molybdenum trioxide, ferrocene, and nickel oxalate dihydrate in a mass ratio of 1:1.5:10;

[0067] The flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate in a mass ratio of 1:5:1:4.

[0068] The preparation method of the strong smoke suppression and flame retardant PVC wood-plastic material specifically comprises the following steps:

[0069] S1. Wood powder end-capping modification:

[0070] Weigh wood powder and add it to 8%wt vinyltriethoxysilane;

[0071] Then add vinyl tri(β-methoxyethoxy)silane until the liquid level completely covers the wood powder;

[0072] After standing for 3 days, the mixed solution of vinyl tri(β-methoxyethoxy)silane and vinyl triethoxysilane was removed and washed with anhydrous ethanol for 6 times;

[0073] The wood powder obtained by filtration was heated in a water bath at a temperature of 50°C for 1 hour, and then dried to obtain modified wood powder;

[0074] S2.PVC wood plastic material preparation:

[0075] First, heat the PVC resin to a molten state, stir it evenly, then add wood powder, calcium carbonate, smoke suppression material, and flame retardant, and mix the above components evenly;

[0076] Then, calcium bicarbonate, silica gel, titanate, processing aid and silicone oil are added to the mixed system, and stirred to react;

[0077] After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

[0078] Embodiment 4 is different from Embodiment 2 in that:

[0079] The smoke suppression material comprises ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:1:8.

[0080] Embodiment 5 is different from Embodiment 2 in that:

[0081] The highly smoke-suppressing and flame-retardant PVC wood-plastic material also includes 15 parts of ABS resin.

[0082] When preparing PVC wood-plastic material, first heat the ABS resin to a molten state, then add the PVC resin, stir the two together evenly, cool to 160°C, and then add wood powder, calcium carbonate, smoke suppression material, and flame retardant.

[0083] Comparative Example 1 is different from Example 5 in that:

[0084] Delete ferrous oxalate dihydrate from smoke suppression materials.

[0085] Comparative Example 2 is different from Example 5 in that:

[0086] Delete ferrocene from smoke suppression materials.

[0087] Comparative Example 3 is different from Example 5 in that:

[0088] The smoke suppression material comprises a magnesium-zinc complex, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6.

[0089] Comparative Example 4 is different from Example 5 in that:

[0090] The smoke suppression material comprises ammonium phosphomolybdate, magnesium-zinc complex and ferrous oxalate dihydrate in a mass ratio of 1:0.75:6.

[0091] Comparative Example 5 is different from Example 5 in that:

[0092] Do not add smoke suppression materials to the PVC wood-plastic material system.

[0093] Comparative Example 6 is different from Example 5 in that:

[0094] The smoke suppression material comprises ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:1.2:12.

[0095] Comparative Example 7 is different from Example 5 in that:

[0096] The smoke suppression material comprises ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:0.3:3.

[0097] Comparative Example 8 is different from Example 5 in that:

[0098] Remove ammonium polyphosphate from flame retardants.

[0099] Comparative Example 9 is different from Example 5 in that:

[0100] Remove zinc borate from flame retardants.

[0101] Comparative Example 10 is different from Example 5 in that:

[0102] Remove zinc borate and melamine cyanurate from flame retardants.

[0103] Comparative Example 11 is different from Example 5 in that:

[0104] The flame retardant comprises red phosphorus, aluminum hydroxide, zinc borate and melamine cyanurate in a mass ratio of 1:3.5:0.5:3.

[0105] Comparative Example 12 is different from Example 5 in that:

[0106] The flame retardant comprises red phosphorus, aluminum hydroxide, magnesium hydroxide and melamine cyanurate in a mass ratio of 1:3.5:0.5:3.

[0107] Comparative Example 13 is different from Example 5 in that:

[0108] When the wood powder is end-capped and modified, vinyl tri(β-methoxyethoxy)silane is replaced by vinyl trimethoxysilane.

[0109] Comparative Example 14 is different from Example 5 in that:

[0110] The wood flour is not end-capped and modified.

[0111] Performance Testing

[0112] The smoke suppression performance and flame retardant performance of the PVC wood-plastic materials prepared by Examples 1-5 and Comparative Examples 1-14 were tested, and the test results are recorded in Table 1.

[0113] Limiting oxygen index determination: An oxygen index meter is used to measure the limiting oxygen index (LOI) of wood-plastic composite materials in accordance with GB / T 2406.2-2009 to characterize the flame retardant properties of the material. The larger the limiting oxygen index, the more difficult it is for the material to burn.

[0114] Cone calorimetry: The sample size is 100mm×100mm×5mm, and the test is carried out in accordance with ISO5660-1 "Combustion Heat Release Rate Test" standard, and the heat radiation power is 50kW / m 2 The heat release rate is a basic parameter that reflects the development of fire and determines the indoor temperature and smoke production. The smaller the value, the less heat is released and the slower the flame propagation speed.

[0115] Smoke density: used to characterize the smoke suppression performance of materials, tested according to ASTM D2843 standard. According to the test results, it is divided into three grades: A, B, and C. Grade A means the lowest smoke density, and grade C means the highest smoke density.

[0116] Table 1 - Smoke suppression and flame retardant performance data of materials prepared in Examples 1-5 and Comparative Examples 1-14

[0117]

[0118]

[0119] From Table 1, we can see that

[0120] 1. It can be seen from the test data of Examples 1-5 that the PVC wood-plastic material prepared by the present invention has excellent flame retardant and smoke suppression properties, especially after adding ABS resin to the system. This is probably because the ABS resin and the smoke suppression material ferrocene have a synergistic effect. The addition of ABS resin changes the action phase of ferrocene, so that it can continue to play a smoke suppression role in the gas phase, thereby improving the smoke suppression effect;

[0121] 2. It can be seen from the test data of Example 5 and Comparative Examples 1-7 that the smoke suppression material of the present invention has excellent smoke suppression and flame retardant properties, and the three components of ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate have a synergistic effect. By controlling the three components within a reasonable ratio range, the smoke suppression effect can be maximized;

[0122] 3. It can be seen from the test data of Example 5 and Comparative Examples 8-12 that the ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate used in the flame retardant of the present invention have a synergistic effect, which can significantly improve the flame retardant properties of PVC wood-plastic materials;

[0123] 4. It can be seen from the test data of Example 5 and Comparative Examples 13-14 that end-capping modification of wood powder can affect the flame retardant and smoke suppression properties of PVC wood-plastic materials to a certain extent, and vinyl tri(β-methoxyethoxy) silane and vinyl triethoxy silane have a certain synergistic effect.

[0124] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0125] 1. The smoke suppression material is added to the PVC wood-plastic material system disclosed in the present invention. The smoke suppression material is a composition of a molybdenum compound, ferrocene and dihydrated oxalate. The molybdenum compound mainly plays a role in the PVC wood-plastic solid phase material, and promotes the formation of a carbon layer and reduces the amount of smoke through Lewis acid. That is to say, at the beginning of combustion, the molybdenum compound can produce a smoke suppression effect; ferrocene in the chlorine-containing PVC system mainly plays a smoke suppression role in the condensed phase. When the combustion proceeds to a certain extent (usually the middle stage), that is, when a certain amount of gas is generated, ferrocene can play a role to the maximum extent, avoiding the problem of a decrease in the smoke suppression effect of the PVC wood-plastic material in the middle stage of combustion; dihydrated oxalate itself produces a smoke suppression effect by cross-linking with PVC and promoting the formation of a carbon layer. At the same time, in the smoke suppression process, it can synergize with the molybdenum compound and dihydrated oxalate to play a smoke suppression and synergistic role.

[0126] 2. Before preparing the PVC wood-plastic material, the present invention first uses two silane coupling agents to end-cap and modify the wood powder. The two silane coupling agents cooperate with each other to improve the flame retardancy of the wood powder, the interface bonding strength with organic matter and the stability of the system.

[0127] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0128] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A strong smoke suppression and flame retardant PVC wood plastic material, characterized in that: The invention comprises the following components in parts by weight: 70-100 parts of PVC resin, 20-30 parts of wood powder, 20-30 parts of calcium carbonate, 15-20 parts of smoke suppression material, 10-15 parts of flame retardant, 1-6 parts of foaming agent, 5-10 parts of stabilizer, 1-2 parts of coupling agent, 5-10 parts of processing aid and 1-4 parts of lubricant; wherein the smoke suppression material comprises molybdenum compound, ferrocene and dihydrate oxalate in a mass ratio of 1:(0.5-1.5):(5-10).

2. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 1, characterized in that: The molybdenum compound is any one of ammonium octamolybdate, molybdenum trioxide, octamolybdate trimethyleneamine, and ammonium phosphomolybdate; the dihydrate oxalate is any one of manganese oxalate dihydrate, ferrous oxalate dihydrate, cobalt oxalate dihydrate, nickel oxalate dihydrate, and copper oxalate dihydrate.

3. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 2, characterized in that: The smoke suppression material comprises ammonium phosphomolybdate, ferrocene and ferrous oxalate dihydrate in a mass ratio of 1:(0.5-1):(5-8).

4. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 3, characterized in that: The flame retardant comprises ammonium polyphosphate, aluminum hydroxide, zinc borate and melamine cyanurate in a mass ratio of 1:(2.5-5):(0.1-1):(1-4).

5. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 1, characterized in that: It also includes 10-20 parts of ABS resin.

6. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 1, characterized in that: The foaming agent is one of azodicarbonamide and calcium bicarbonate or a mixture of both.

7. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 1, characterized in that: The stabilizer is any one of a calcium zinc stabilizer, a zeolite, and a silica gel.

8. The strong smoke suppression and flame retardant PVC wood-plastic material according to claim 1, characterized in that: The coupling agent is titanate or aluminate.

9. The method for preparing the highly smoke-suppressing and flame-retardant PVC wood-plastic material according to any one of claims 1 to 8, characterized in that: The specific steps include: S1. Wood powder end-capping modification: Weigh wood powder and add it to 8%wt triethoxysilane; Then add vinyl tri(β-methoxyethoxy)silane until the liquid level completely covers the wood powder; After standing for 2 to 3 days, the mixed solution of vinyl tri(β-methoxyethoxy)silane and triethoxysilane was removed, and the mixture was washed with anhydrous ethanol for 4 to 6 times; The wood powder obtained by filtration is heated in a water bath at a temperature of 30 to 50° C. for 1 to 2 hours, and then dried to obtain modified wood powder; S2.PVC wood plastic material preparation: First, heat the PVC resin to a molten state, stir it evenly, then add wood powder, calcium carbonate, smoke suppression material, and flame retardant, and mix the above components evenly; Then, a foaming agent, a stabilizer, a coupling agent, a processing aid, and a lubricant are added to the mixed system, and stirred to react; After the reaction is completed, the PVC wood-plastic material is melt-extruded, pressed into shape, crushed and sieved to obtain the finished product.

10. The method for preparing the highly smoke-suppressing and flame-retardant PVC wood-plastic material according to any one of claim 9, characterized in that: In S2, the ABS resin is first heated to a molten state, and then the PVC resin is added. After the two are stirred and melted evenly, the temperature is lowered and then wood powder, calcium carbonate, smoke suppression material, and flame retardant are added.

Images