Self-extinguishing low-smoke polyvinyl chloride composite material, preparation method and application thereof

Abstract

The application provides a self-extinguishing low-smoke polyvinyl chloride composite material and a preparation method and application thereof, and belongs to the technical field of polyvinyl chloride material processing. The self-extinguishing low-smoke polyvinyl chloride composite material comprises the following raw materials in mass fractions: 150-200 parts of polyvinyl chloride resin, 30-50 parts of magnesium hydroxide, 5-10 parts of manganese compound, 30-50 parts of plasticizer and 1-5 parts of stabilizer. The manganese ion and the magnesium hydroxide synergistically promote the combustion part of the polyvinyl chloride to be firmly combined in the form of a condensed phase residual carbon layer on the surface of the unburned polyvinyl chloride composite material, greatly reducing the escape of the partial combustion smoke solid particles in the air, thereby inhibiting the further combustion of the flame, having excellent flame-retardant performance and inhibition capacity, and further expanding the application field of the polyvinyl chloride composite material.

Description

Technical Field

[0001] This invention relates to the field of polyvinyl chloride composite material processing technology, and in particular to a self-extinguishing, low-smoke polyvinyl chloride composite material, its preparation method, and its application. Background Technology

[0002] Polyvinyl chloride (PVC) is a thermoplastic resin and was once the world's largest-produced general-purpose plastic. It is widely used in building materials, industrial products, daily necessities, flooring, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foaming materials, sealing materials, and fibers. PVC products have high dimensional stability, good surface finish, and excellent water, oil, and corrosion resistance. However, PVC composites have poor light and heat stability. At temperatures above 100°C or after prolonged exposure to sunlight, they decompose to produce hydrogen chloride, which further autocatalytically decomposes, causing discoloration and a rapid decline in physical and mechanical properties. In practical applications, stabilizers must be added to improve thermal and light stability, and plasticizers are added to improve mechanical properties. However, the addition of plasticizers significantly deteriorates the flame retardant properties of PVC composites. To improve its flame retardancy, antimony trioxide is generally added as a flame retardant. However, due to the high price of antimony trioxide and its tendency to produce large amounts of harmful environmental and safety byproducts, the industry is currently seeking new flame retardants to replace antimony trioxide. Magnesium hydroxide is considered an effective alternative to antimony trioxide as a flame retardant. However, although the addition of magnesium hydroxide to PVC composite materials significantly improves smoke suppression, the limiting oxygen index is not high, and the flame retardant ability still needs to be improved.

[0003] Given this situation, the main solution emerging in the market is to compound magnesium hydroxide, hoping to improve the flame retardant properties of composite materials by introducing other flame-retardant components into the magnesium hydroxide compound. The problem is that while the composite flame retardant formed by combining traditional flame retardants with magnesium hydroxide can significantly improve the flame retardant properties of composite materials, the traditional flame-retardant components have conflicting effects with magnesium hydroxide in terms of smoke suppression, which severely affects the smoke suppression ability of the composite material. Summary of the Invention

[0004] The purpose of this invention is to provide a self-extinguishing, low-smoke polyvinyl chloride composite material, its preparation method, and its application, so as to simultaneously improve the flame retardant properties and smoke suppression capabilities of the composite material.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a self-extinguishing, low-smoke polyvinyl chloride composite material, comprising the following raw materials in parts by weight:

[0007] 150-200 parts of polyvinyl chloride resin, 30-50 parts of magnesium hydroxide, 5-10 parts of manganese compound, 30-50 parts of plasticizer and 1-5 parts of stabilizer.

[0008] Preferably, the manganese compound includes one or more of manganese monoxide, manganese dioxide, manganese trioxide, manganese hydroxide, manganese sulfate, manganese chloride, and manganese nitrate.

[0009] Preferably, the plasticizer includes phthalates.

[0010] Preferably, the stabilizer includes one or more of zinc stearate, cadmium stearate, calcium stearate, dibutyltin dilaurate, dibutyltin dimaleate, and calcium zinc hydrotalcite stabilizer.

[0011] This invention provides a method for preparing the self-extinguishing, low-smoke polyvinyl chloride composite material described in the above technical solution, comprising the following steps:

[0012] Magnesium hydroxide, manganese compounds, and activators are mixed to carry out an activation reaction, yielding an activated product.

[0013] The activated product, polyvinyl chloride resin, plasticizer and stabilizer are mixed and grafted plasticized to obtain a self-extinguishing low-smoke polyvinyl chloride composite material.

[0014] Preferably, the activator includes one of ethanol, methanol, propanol, or ethylene glycol; the mass of the activator is 10-15% of the total mass of the magnesium hydroxide and the manganese compound.

[0015] Preferably, the activation reaction is carried out at a temperature of 70–130°C for a time of 10–120 min.

[0016] Preferably, the grafting and plasticizing temperature is 30–180°C and the time is 10–90 min.

[0017] The present invention also provides the application of the self-extinguishing low-smoke polyvinyl chloride composite material described in the above technical solution or the self-extinguishing low-smoke polyvinyl chloride composite material prepared by the preparation method described in the above technical solution in fireproof materials.

[0018] The beneficial effects of this invention are:

[0019] This invention improves the flame retardant and smoke suppression properties of polyvinyl chloride (PVC) composites by adding manganese compounds and magnesium hydroxide to traditional PVC resin. Manganese ions catalyze the oxidation of PVC alkane branches to form hydroxyl or carboxyl functional groups, which then form organic bonds with the hydroxyl groups on magnesium hydroxide. Simultaneously, the magnesium oxide produced by the thermal decomposition of magnesium hydroxide also has a certain physical adsorption effect. These two elements synergistically promote the firm bonding of the burned PVC to the surface of the unburned PVC composite material in the form of a condensed phase char layer, forming a stable char layer. This layer inhibits further combustion of the flame by isolating combustibles, significantly reducing the escape of some combustion smoke particles into the air and improving the smoke suppression ability of the composite material. Furthermore, the significant increase in the mass of the condensed phase char layer also forms an effective physical barrier, greatly improving the flame retardant properties of the composite material to a certain extent.

[0020] The self-extinguishing, low-smoke polyvinyl chloride composite material prepared by this invention has excellent smoke suppression and flame retardant properties, with a maximum smoke density ≤45.00, smoke density grade ≤38.46, limiting oxygen index ≥30.8, and char residue ≥60.4%. At the same time, manganese compounds are more cost-effective than traditional flame retardants such as antimony trioxide. Attached Figure Description

[0021] Figure 1 The TGA images are of the condensed phase carbon residue of the self-extinguishing low-smoke polyvinyl chloride composite material in Example 1 and Comparative Examples 1 and 2 under air atmosphere.

[0022] Figure 2 This is a SEM image of the condensed phase carbon layer of the self-extinguishing low-smoke polyvinyl chloride composite material in Comparative Example 1.

[0023] Figure 3 This is a SEM image of the condensed phase residual carbon layer of the self-extinguishing low-smoke polyvinyl chloride composite material in Comparative Example 2.

[0024] Figure 4 This is a SEM image of the condensed phase residual carbon layer of the self-extinguishing low-smoke polyvinyl chloride composite material in Example 1.

[0025] Figure 5 This diagram illustrates the difference between the flame-retardant methods of the self-extinguishing, low-smoke polyvinyl chloride composite material of this invention and conventional polyvinyl chloride materials. Detailed Implementation

[0026] This invention provides a self-extinguishing, low-smoke polyvinyl chloride composite material, comprising the following raw materials in parts by weight:

[0027] 150-200 parts of polyvinyl chloride resin, 30-50 parts of magnesium hydroxide, 5-10 parts of manganese compound, 30-50 parts of plasticizer and 1-5 parts of stabilizer.

[0028] In this invention, unless otherwise specified, all raw materials required for preparation are commercially available products well known to those skilled in the art.

[0029] In this invention, the polyvinyl chloride resin is preferably 150-200 parts by weight, more preferably 160-200 parts by weight, and even more preferably 170-200 parts by weight. This invention does not impose any special limitation on the source of the polyvinyl chloride resin; commercially available products well-known in the art are acceptable. In the embodiments of this invention, the polyvinyl chloride resin is preferably derived from products of Gansu Yinda Chemical Co., Ltd.

[0030] Based on the mass fraction of the polyvinyl chloride resin, the mass fraction of magnesium hydroxide in this invention is preferably 30-50 parts, more preferably 30-45 parts, and even more preferably 30-42 parts; the magnesium hydroxide in this invention is preferably ultrafine magnesium hydroxide, and the mesh size of the ultrafine magnesium hydroxide is preferably ≥2000 mesh, more preferably 6000 mesh; the ultrafine magnesium hydroxide is preferably sourced from Jiangxi Guangyuan Chemical Group, with product number GY-6000; the magnesium hydroxide in this invention is an ultra-high mesh magnesium hydroxide product produced by crushing raw ore, which has strong hydrophilicity, a large contact area with polyvinyl chloride, and a good modification effect on polyvinyl chloride.

[0031] Based on the mass fraction of the polyvinyl chloride resin, the mass fraction of the manganese compound in this invention is preferably 5 to 10 parts, more preferably 5 to 8 parts; the manganese compound preferably includes one or more of manganese monoxide, manganese dioxide, manganese trioxide, manganese hydroxide, manganese sulfate, manganese chloride, and manganese nitrate, more preferably one or more of manganese monoxide, manganese dioxide, manganese trioxide, manganese sulfate, manganese chloride, and manganese nitrate; manganese ions can catalytically oxidize the alkane branches of PVC to form oxidizing functional groups such as hydroxyl or carboxyl groups. When the alkane molecular chain is catalytically oxidized, the resulting combustion products can quickly combine with magnesium hydroxide, driving the aggregation of the surrounding PVC composite material. The rapid aggregation of a large amount of PVC composite material will cause the oxygen required for combustion to become "deficient" in a short time, thereby achieving a quenching effect and realizing self-extinguishing flame retardancy.

[0032] Based on the mass fraction of the polyvinyl chloride resin, the mass fraction of the plasticizer is preferably 30-50 parts, more preferably 30-40 parts; the present invention does not have a special limitation on the type of plasticizer, and any plasticizer commonly used in the art is acceptable; in the embodiments of the present invention, the plasticizer is preferably phthalate, and the phthalate is sourced from Shanghai Maclean Biochemical Technology Co., Ltd.

[0033] Based on the mass fraction of the polyvinyl chloride resin, the mass fraction of the stabilizer is preferably 1 to 5 parts, more preferably 2 to 5 parts; the stabilizer preferably includes one or more of zinc stearate, cadmium stearate, calcium stearate, dibutyltin dilaurate, dibutyltin dimaleate, and calcium zinc hydrotalcite stabilizer, more preferably one or more of zinc stearate, cadmium stearate, calcium stearate, and calcium zinc hydrotalcite stabilizer.

[0034] This invention provides a method for preparing the self-extinguishing, low-smoke polyvinyl chloride composite material described in the above technical solution, comprising the following steps:

[0035] Magnesium hydroxide, manganese compounds, and activators are mixed to carry out an activation reaction, yielding an activated product.

[0036] The activated product, polyvinyl chloride resin, plasticizer and stabilizer are mixed and grafted plasticized to obtain a self-extinguishing low-smoke polyvinyl chloride composite material.

[0037] In this invention, the activator preferably includes one of ethanol, methanol, propanol or ethylene glycol; the mass of the activator is preferably 10-15% of the total mass of the magnesium hydroxide and the manganese compound, more preferably 10-12%.

[0038] In this invention, the temperature of the activation reaction is preferably 70-130°C, more preferably 80-120°C, and even more preferably 90-120°C; the time is preferably 10-120 min, more preferably 10-110 min, and even more preferably 10-100 min.

[0039] In this invention, the grafting and plasticizing temperature is preferably 30-180°C, more preferably 40-180°C, and even more preferably 60-180°C; the time is preferably 10-90 min, more preferably 10-75 min, and even more preferably 10-55 min.

[0040] In this invention, the activation reaction and the grafting polymerization reaction are preferably carried out under stirring conditions, and the stirring speed is preferably 400-1200 rpm, more preferably 500-1100 rpm, and even more preferably 600-1000 rpm.

[0041] The present invention also provides the application of the self-extinguishing low-smoke polyvinyl chloride composite material described in the above technical solution or the self-extinguishing low-smoke polyvinyl chloride composite material prepared by the preparation method described in the above technical solution in fireproof materials.

[0042] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0043] The polyvinyl chloride resin used in Examples 1-15 and Comparative Examples 1-2 of this invention was sourced from Gansu Yinda Chemical Co., Ltd.; the magnesium hydroxide used was 6000 mesh and sourced from Jiangxi Guangyuan Chemical Group, product number GY-6000; the phthalate used was sourced from Shanghai Maclean Biochemical Technology Co., Ltd.

[0044] The manganese compounds and stabilizers used in Examples 1-15 and Comparative Examples 1-2 of this invention are all commercially available products, and there are no specific requirements regarding their source.

[0045] Example 1

[0046] Mix 50g magnesium hydroxide, 5g manganese dioxide and 15mL ethanol, and carry out the activation reaction at 120℃ for 10min under stirring at 800rpm to obtain the activated product.

[0047] The activated product was mixed with 200g of PVC resin, 30g of phthalate and 2g of hydrotalcite calcium zinc stabilizer, and heated at 170°C for 15min under stirring at 800rpm to obtain the self-extinguishing low-smoke polyvinyl chloride composite material of Example 1.

[0048] Example 2

[0049] The only difference from Example 1 is:

[0050] The manganese compound used is manganese monoxide;

[0051] The stabilizer used is zinc stearate;

[0052] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 2 was obtained.

[0053] Example 3

[0054] The only difference from Example 1 is:

[0055] The manganese compound used is manganese trioxide;

[0056] The stabilizer used is cadmium stearate;

[0057] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 3 was obtained.

[0058] Example 4

[0059] The only difference from Example 1 is:

[0060] The manganese compound used is manganese nitrate;

[0061] The stabilizer used is calcium stearate;

[0062] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 4 was obtained.

[0063] Example 5

[0064] The only difference from Example 1 is:

[0065] The manganese compound used is manganese chloride;

[0066] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 5 was obtained.

[0067] Example 6

[0068] The only difference from Example 1 is:

[0069] The activation reaction was carried out at a temperature of 90℃ for 30 minutes.

[0070] The graft polymerization reaction was carried out at a temperature of 150℃ for 25 minutes.

[0071] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 6 was obtained.

[0072] Example 7

[0073] The only difference from Example 2 is:

[0074] The activation reaction was carried out at a temperature of 90℃ for 30 minutes.

[0075] The graft polymerization reaction was carried out at a temperature of 150℃ for 25 minutes.

[0076] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 7 was obtained.

[0077] Example 8

[0078] The only difference from Example 3 is that:

[0079] The activation reaction was carried out at a temperature of 90℃ for 30 minutes.

[0080] The graft polymerization reaction was carried out at a temperature of 150℃ for 25 minutes.

[0081] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 8 was obtained.

[0082] Example 9

[0083] The only difference from Example 4 is that:

[0084] The activation reaction was carried out at a temperature of 90℃ for 30 minutes.

[0085] The graft polymerization reaction was carried out at a temperature of 150℃ for 25 minutes.

[0086] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 9 was obtained.

[0087] Example 10

[0088] The only difference from Example 5 is that:

[0089] The activation reaction was carried out at a temperature of 90℃ for 30 minutes.

[0090] The graft polymerization reaction was carried out at a temperature of 150℃ for 25 minutes.

[0091] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 10 was obtained.

[0092] Example 11

[0093] The only difference from Example 1 is:

[0094] The activation reaction time is 30 min;

[0095] The graft polymerization reaction time was 25 min;

[0096] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 11 was obtained.

[0097] Example 12

[0098] The only difference from Example 2 is:

[0099] The activation reaction time is 30 min;

[0100] The graft polymerization reaction time was 25 min;

[0101] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 12 was obtained.

[0102] Example 13

[0103] The only difference from Example 3 is that:

[0104] The activation reaction time is 30 min;

[0105] The graft polymerization reaction time was 25 min;

[0106] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 13 was obtained.

[0107] Example 14

[0108] The only difference from Example 4 is that:

[0109] The activation reaction time is 30 min;

[0110] The graft polymerization reaction time was 25 min;

[0111] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 14 was obtained.

[0112] Example 15

[0113] The only difference from Example 5 is that:

[0114] The activation reaction time is 30 min;

[0115] The graft polymerization reaction time was 25 min;

[0116] The self-extinguishing, low-smoke polyvinyl chloride composite material of Example 15 was obtained.

[0117] Comparative Example 1

[0118] The only difference from Example 1 is:

[0119] No manganese dioxide was added;

[0120] A self-extinguishing, low-smoke polyvinyl chloride composite material, as described in Comparative Example 1, was obtained.

[0121] Comparative Example 2

[0122] The only difference from Example 1 is:

[0123] No magnesium hydroxide was added;

[0124] The self-extinguishing, low-smoke polyvinyl chloride composite material of Comparative Example 2 was obtained.

[0125] Performance testing

[0126] The composite materials obtained in Examples 1-15 and Comparative Examples 1-2 were subjected to performance tests, and the test results are recorded in Table 1:

[0127] (1) Maximum smoke density and smoke density level test: Tested according to GB / T8627-2007 standard;

[0128] (2) Limiting oxygen index test: Tested according to GB / T2406.2-2009 standard;

[0129] (3) Determination of char rate: Weigh the standard sample in (1) before combustion. After the combustion test, weigh the remaining mass. Calculate the char rate by the ratio of the remaining mass to the initial mass.

[0130] Table 1. Test results of the composite materials obtained in Examples 1-15 and Comparative Examples 1-2.

[0131]

[0132]

[0133] The results of Examples 1, 1, and 2 show that the flame retardant properties and smoke suppression capabilities of the PVC composite material are significantly different when either magnesium hydroxide or manganese compound is absent. This indicates a clear synergistic flame retardant effect between magnesium hydroxide and manganese compound, and that manganese compound needs to be combined with magnesium hydroxide to exhibit a significant flame retardant effect. This suggests that the catalytic flame retardant effect of manganese compound is synergistic, with magnesium hydroxide as the primary flame retardant. With the addition of both magnesium hydroxide and manganese compound, the flame retardant properties and smoke suppression capabilities of the PVC composite material are significantly enhanced, with a marked improvement in limiting oxygen index, maximum smoke density, and smoke density rating.

[0134] After testing the smoke density level and maximum smoke density of the samples, the condensed phase char layer was collected. Under air atmosphere, the mass change of the condensed phase char layer of the self-extinguishing low-smoke PVC composite material prepared with magnesium hydroxide and manganese compounds in Example 1, magnesium hydroxide only in Comparative Example 1, and manganese compounds only in Comparative Example 2 was determined using a thermogravimetric analyzer at different temperatures. Figure 1 .from Figure 1 It can be seen that the pyrolysis curves of the three are different. Only the pyrolysis curves of adding one of them as flame retardants are similar, and the decomposition temperature is low, and the condensed phase char layer is not stable enough. On the contrary, the pyrolysis temperature of the condensed phase char layer of the composite material with added magnesium hydroxide and manganese compounds is significantly higher, indicating that its condensed phase char layer is more stable.

[0135] The condensed phase carbon residue of the self-extinguishing low-smoke polyvinyl chloride composite materials in Comparative Examples 1-2 and Example 1 was observed using a scanning electron microscope, and the results were obtained. Figures 2-4 .from Figure 2 , Figure 3 and Figure 4It can be seen that the PVC composite material with only magnesium hydroxide added has a relatively dense surface, but the physical adsorption capacity of the magnesium oxide generated by its decomposition is limited, and the condensed phase char layer of the composite material is still not stable and strong enough. On the other hand, the condensed phase char layer of the PVC composite material with only manganese compound added is obviously denser, and the difference can also be clearly observed from the char rate. This is because the catalytic flame retardant effect of manganese ions can concentrate the surrounding PVC alkane molecular chains over a large area in a short time, causing an instantaneous "depletion" of oxygen, achieving a quenching effect. However, this may also lead to more intense secondary combustion, so its limiting oxygen index is lower. But when magnesium hydroxide and manganese compound are added at the same time, the condensed phase char layer of the PVC composite material is strong and dense. At the same time, magnesium hydroxide and manganese compound work together to quench the flame, forming a series of physical barriers mainly composed of magnesium oxide while quenching the flame in a short time, preventing the continued spread of combustion. Compared with traditional flame retardants such as antimony trioxide, manganese compound is more environmentally friendly and more affordable while maintaining excellent flame retardant performance and smoke suppression ability. It can broaden the application of manganese compound catalytic flame retardancy and further obtain PVC composite materials with even better flame retardant performance and smoke suppression ability.

[0136] To further illustrate the difference between the flame-retardant methods of the self-extinguishing, low-smoke PVC composite material of this invention and conventional PVC materials, such as... Figure 5 As shown, conventional polyvinyl chloride (PVC) materials contain magnesium hydroxide flame retardant and additives, which release CO2, CO, and HCl during combustion. Adding magnesium hydroxide alone cannot effectively curb the spread of combustion. However, the composite material of this invention uses magnesium hydroxide and manganese compounds as flame retardants. During combustion, the PVC in the combustion zone firmly covers the surface of the unburned material in the form of a condensed phase char layer, forming a solid protective barrier. This greatly reduces the escape of some combustion smoke solid particles into the air, inhibits further combustion of the flame by isolating combustibles, significantly slows down the spread of fire, and greatly reduces gas emissions during combustion. To a certain extent, this improves both the flame retardant and smoke suppression properties of the composite material.

[0137] As can be seen from Examples 1-15 and Comparative Examples 1-2 above, the self-extinguishing low-smoke polyvinyl chloride composite material prepared by the present invention has a maximum smoke density ≤45.00, a smoke density grade ≤38.46, a limiting oxygen index ≥30.8, and a char residue rate ≥60.4%, which gives it high added value and further expands the application field of polyvinyl chloride composite materials.

[0138] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a self-extinguishing, low-smoke polyvinyl chloride composite material, characterized in that, Includes the following steps: Magnesium hydroxide, manganese compounds, and activators are mixed to carry out an activation reaction, yielding an activated product. The activated product, polyvinyl chloride resin, plasticizer and stabilizer are mixed and grafted plasticized to obtain a self-extinguishing low-smoke polyvinyl chloride composite material. The manganese compound is one or more of manganese monoxide, manganese dioxide, manganese trioxide, manganese hydroxide, manganese sulfate, manganese chloride, and manganese nitrate. The activator is one of ethanol, methanol, propanol or ethylene glycol; The self-extinguishing, low-smoke polyvinyl chloride composite material comprises the following raw materials in parts by weight: 150-200 parts of polyvinyl chloride resin, 30-50 parts of magnesium hydroxide, 5-10 parts of manganese compound, 30-50 parts of plasticizer and 1-5 parts of stabilizer; The self-extinguishing, low-smoke polyvinyl chloride composite material further includes an activator, the mass of which is 10-15% of the total mass of the magnesium hydroxide and the manganese compound.

2. The preparation method according to claim 1, characterized in that, The plasticizer is phthalate.

3. The preparation method according to claim 1, characterized in that, The stabilizer is one or more of zinc stearate, cadmium stearate, calcium stearate, dibutyltin dilaurate, dibutyltin dimaleate, and hydrotalcite calcium zinc stabilizer.

4. The preparation method according to claim 1, characterized in that, The activation reaction is carried out at a temperature of 70–130°C for a time of 10–120 min.

5. The preparation method according to claim 1, characterized in that, The grafting and plasticizing temperature is 30–180°C, and the time is 10–90 min.

6. The application of the self-extinguishing, low-smoke polyvinyl chloride composite material prepared by the preparation method according to any one of claims 1 to 5 in fireproof materials.

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