A preparation process of impact-resistant insulating sheet

Abstract

The invention relates to the technical field of polystyrene, and discloses a process for preparing an impact-resistant insulating sheet. The invention adds modified polyurethane and hydroxylated hexagonal boron nitride into a high-speed mixer for blending, then adds the blended material, polystyrene resin and flame retardant into a twin-screw extruder for granulation, and finally hot-presses and forms the material in a flat vulcanizer to obtain an impact-resistant insulating sheet. The modified polyurethane contains polystyrene segments, which have good compatibility with the polystyrene resin, so that the modified polyurethane has a good toughening effect, and can improve the dispersibility of hexagonal nano boron nitride in the polystyrene resin, further improving the mechanical properties and insulating properties of the sheet. The polystyrene segments of the modified polyurethane contain piperazine groups, which can form nitrogen-phosphorus expansion flame retardants with phosphorus-containing flame retardants such as triphenyl phosphate, which is beneficial to improving the limiting oxygen index of the sheet and improving the flame retardant properties.

Description

Technical Field

[0001] The invention relates to the technical field of polystyrene, in particular to a preparation process of an impact-resistant insulating plate. Background Art

[0002] Polystyrene is a general engineering plastic that can be made into bakelite, laminate, plastic board, foam board, film, etc., and is widely used in construction, insulation, packaging, containers, etc. Traditional polystyrene materials have poor impact resistance and are easy to burn. Adding toughening agents, impact modifiers, etc. to polystyrene can improve its toughness, impact resistance and other properties. Patent CN108948554B discloses that the polyolefin polyurethane elastomer prepared with polyolefin polyol, diisocyanate and diamine chain extender as raw materials has a good toughening effect on polystyrene, but the patent does not improve the flame retardant and insulation properties of polystyrene.

[0003] Hexagonal boron nitride is a high-performance inorganic nanomaterial with high mechanical strength, high insulation performance, and strong thermal conductivity. It has important applications in polymer materials such as plastics, fibers, and rubber. Patent CN105860315B discloses that boron nitride, styrene, coupling agents, initiators, etc. are used as raw materials to improve the compatibility between hexagonal boron nitride and polystyrene, and enhance the mechanical and thermal conductivity properties of polystyrene. However, the patent requires the use of silane coupling agents such as KH-570, and does not improve the impact strength, flame retardancy, and other properties of polystyrene. Summary of the invention

[0004] (I) Technical problems to be solved: The present invention solves the problems of poor impact resistance, insulation and flame retardancy of polystyrene sheets.

[0005] (II) Technical solution: A process for preparing an impact-resistant insulating sheet:

[0006] Step A: Add chloroform and styrene-glycidyl methacrylate copolymer to a flask, stir and add 2-(piperazine-1-yl)acetic acid, stir and react at 50-60° C. for 24-36 hours, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain piperazine acetic acid modified polystyrene copolymer. The reaction formula is:

[0007] Step B: Add polyethylene glycol to a flask, dry and dehydrate, add a diisocyanate compound, introduce nitrogen, heat to 70-75° C., react for 2-3 hours, then add piperazine acetic acid modified polystyrene copolymer, react for 1-1.5 hours, cool, and obtain modified polyurethane.

[0008] Step C: adding modified polyurethane and hydroxylated hexagonal boron nitride into a high-speed mixer for blending, then adding the blend, polystyrene resin and flame retardant into a twin-screw extruder for granulation, and finally hot-pressing in a flat vulcanizer to obtain an impact-resistant insulating sheet.

[0009] Preferably, in step A, the mass of 2-(piperazine-1-yl)acetic acid is 25-60% of the mass of styrene-glycidyl methacrylate copolymer.

[0010] Preferably, in step B, the masses of the diisocyanate compound and the piperazineacetic acid modified polystyrene copolymer are 18-26% and 6-10% of the mass of the polyethylene glycol, respectively; and the molecular weight of the polyethylene glycol is 2000.

[0011] Preferably, the diisocyanate compound is toluene-2,4-diisocyanate or diphenylmethane-4,4′-diisocyanate.

[0012] Preferably, the masses of the modified polyurethane, hydroxylated hexagonal boron nitride, and the flame retardant are 5-20%, 8-15%, and 12-18% of the mass of the polystyrene, respectively.

[0013] Preferably, the flame retardant is triphenyl phosphate or resorcinol bis(diphenyl phosphate).

[0014] Preferably, the preparation process of styrene-glycidyl methacrylate copolymer is as follows: add water, styrene, glycidyl methacrylate, sodium dodecylbenzene sulfonate into a flask, add dibenzoyl peroxide after stirring, heat to 80-85°C, react for 5-7h, filter, wash with water and ethanol, and dry to obtain styrene-glycidyl methacrylate copolymer. The structural formula is: .

[0015] Preferably, the masses of glycidyl methacrylate, sodium dodecylbenzene sulfonate and dibenzoyl peroxide are 12-30%, 2-2.5% and 1.6-2.2% of the mass of styrene, respectively.

[0016] Preferably, the preparation process of hydroxylated hexagonal boron nitride is: adding a sodium hydroxide solution with a mass concentration of 150-200 g / L and hexagonal nano boron nitride into a flask, heating to 95-100° C., stirring and condensing and refluxing for 12-18 hours, filtering, washing with water, and drying to obtain hydroxylated hexagonal boron nitride.

[0017] Technical effect of the present invention: The present invention utilizes styrene-glycidyl methacrylate copolymer and 2-(piperazine-1-yl)acetic acid to carry out a ring-opening reaction to obtain a piperazineacetic acid-modified polystyrene copolymer, the hydroxyl groups contained in the piperazineacetic acid copolymer can be polymerized with polyethylene glycol and a diisocyanate compound to obtain a modified polyurethane containing a polystyrene molecular chain.

[0018] The present invention uses modified polyurethane as a toughening agent, hydroxylated hexagonal boron nitride as an inorganic filler, triphenyl phosphate and the like as a flame retardant, and is compounded with polystyrene resin to obtain an impact-resistant insulating sheet. The modified polyurethane contains polystyrene segments, which have good compatibility with the polystyrene resin, so that the modified polyurethane has a good toughening effect, which is beneficial to improving the bending strength and impact resistance of the polystyrene resin sheet.

[0019] The polystyrene chain segments of the modified polyurethane of the present invention contain carboxyl groups. During the high-temperature blending process, the carboxyl groups can interact with the hydroxyl groups on the surface of the hydroxylated hexagonal boron nitride by hydrogen bonding or the like, so that the modified polyurethane is coated on the surface of the hexagonal boron nitride, thereby improving the dispersibility of the hexagonal nano boron nitride in the polystyrene resin and further improving the mechanical properties of the plate. At the same time, the hexagonal nano boron nitride is uniformly dispersed in the plate matrix, which is beneficial to improving the volume resistivity and insulation performance.

[0020] The polystyrene chain segment of the modified polyurethane of the present invention contains piperazine groups, which can form nitrogen-phosphorus expansion flame retardants with phosphorus-containing flame retardants such as triphenyl phosphate, release non-flammable gases such as nitrogen during combustion, promote the formation of an expansion carbon layer on the board, and play a synergistic flame retardant role with hexagonal nano boron nitride, which is beneficial to improve the limiting oxygen index of the board and improve the flame retardant performance. DETAILED DESCRIPTION

[0021] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the present invention is described in detail below in conjunction with specific embodiments. Unless otherwise specified, the materials, reagents, etc. involved below are all commercially available products well known to those skilled in the art; unless otherwise specified, the methods described are all methods well known in the art.

[0022] Example 1

[0023] (1) Add 70 mL of water, 40 g of styrene, 8.3 g of glycidyl methacrylate, and 0.9 g of sodium dodecylbenzene sulfonate into a flask, stir, add 7.8 g of dibenzoyl peroxide, heat to 80 ° C, react for 7 h, filter, wash with water and ethanol, and dry to obtain styrene-glycidyl methacrylate copolymer.

[0024] (2) Add 1L of 150g / L sodium hydroxide solution and 4g of hexagonal nano boron nitride into a flask, heat to 100°C, stir and condense under reflux for 12h, filter, wash with water, and dry to obtain hydroxylated hexagonal boron nitride.

[0025] (3) Add 120 mL of chloroform and 8 g of styrene-glycidyl methacrylate copolymer into a flask, stir, then add 3.5 g of 2-(piperazine-1-yl)acetic acid (CAS No. 37478-58-3), stir and react at 55 °C for 36 h, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain piperazine acetic acid modified polystyrene copolymer.

[0026] (4) Add 100 g of polyethylene glycol 2000 to a flask, dry and dehydrate, add 26 g of diphenylmethane-4,4'-diisocyanate, introduce nitrogen, heat to 75°C, react for 2 h, then add 6 g of piperazine acetic acid modified polystyrene copolymer, react for 1 h, cool, and obtain modified polyurethane.

[0027] (5) Add 50g of modified polyurethane and 80g of hydroxylated hexagonal boron nitride into a high-speed mixer and blend for 2h at a blending temperature of 80°C. Then add the blend, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation at a melting temperature of 195°C and a screw speed of 150r / min. Finally, hot press molding is performed in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0028] Example 2

[0029] (1) Add 100 mL of water, 40 g of styrene, 12 g of glycidyl methacrylate, and 1 g of sodium dodecylbenzene sulfonate to a flask, stir, add 8.8 g of dibenzoyl peroxide, heat to 85°C, react for 7 h, filter, wash with water and ethanol, and dry to obtain styrene-glycidyl methacrylate copolymer.

[0030] (2) Add 1L of 200g / L sodium hydroxide solution and 4g of hexagonal nano boron nitride into a flask, heat to 100°C, stir and condense under reflux for 12h, filter, wash with water, and dry to obtain hydroxylated hexagonal boron nitride.

[0031] (3) Add 140 mL of chloroform and 8 g of styrene-glycidyl methacrylate copolymer into a flask, stir, then add 4.8 g of 2-(piperazine-1-yl)acetic acid, stir and react at 60 °C for 36 h, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain piperazine acetic acid modified polystyrene copolymer.

[0032] (4) Add 100 g of polyethylene glycol 2000 to a flask, dry and dehydrate, add 18 g of toluene-2,4-diisocyanate, introduce nitrogen, heat to 75°C, react for 2 h, then add 8 g of piperazine acetic acid modified polystyrene copolymer, react for 1.5 h, cool, and obtain modified polyurethane.

[0033] (5) Add 120g of modified polyurethane and 120g of hydroxylated hexagonal boron nitride into a high-speed mixer and blend for 2h at a blending temperature of 80°C. Then, add the blend, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation at a melting temperature of 195°C and a screw speed of 150r / min. Finally, hot-press mold the mixture in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0034] Example 3

[0035] (1) Add 60 mL of water, 40 g of styrene, 4.8 g of glycidyl methacrylate, and 0.8 g of sodium dodecylbenzene sulfonate to a flask, stir, add 6.4 g of dibenzoyl peroxide, heat to 85 °C, react for 5 h, filter, wash with water and ethanol, and dry to obtain styrene-glycidyl methacrylate copolymer.

[0036] (2) Add 1L of 150g / L sodium hydroxide solution and 4g of hexagonal nano boron nitride into a flask, heat to 95°C, stir and condense under reflux for 18h, filter, wash with water, and dry to obtain hydroxylated hexagonal boron nitride.

[0037] (3) Add 80 mL of chloroform and 8 g of styrene-glycidyl methacrylate copolymer into a flask, stir, then add 2 g of 2-(piperazine-1-yl)acetic acid, stir and react at 50 °C for 24 h, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain piperazine acetic acid modified polystyrene copolymer.

[0038] (4) Add 100 g of polyethylene glycol 2000 to a flask, dry and dehydrate, add 26 g of diphenylmethane-4,4'-diisocyanate, introduce nitrogen, heat to 70°C, react for 3 h, then add 10 g of piperazineacetic acid modified polystyrene copolymer, react for 1.5 h, cool, and obtain modified polyurethane.

[0039] (5) Add 200 g of modified polyurethane and 150 g of hydroxylated hexagonal boron nitride into a high-speed mixer and blend for 2 h at a blending temperature of 80 °C. Then add the blend, 1 kg of polystyrene resin, and 120 g of flame retardant hydroquinone bis(diphenyl phosphate) into a twin-screw extruder for granulation at a melting temperature of 195 °C and a screw speed of 150 r / min. Finally, hot-press mold the mixture in a flat vulcanizer at a temperature of 190 °C and a pressure of 10 MPa to obtain an impact-resistant insulating sheet.

[0040] The difference between Comparative Example 1 and Example 1 is that modified polyurethane and hydroxylated hexagonal boron nitride are not added, specifically as follows:

[0041] (1) Add 1 kg of polystyrene resin and 180 g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation, with a melting temperature of 195°C and a screw speed of 150 r / min; finally, hot press molding is performed in a flat vulcanizer at a temperature of 190°C and a pressure of 10 MPa to obtain an impact-resistant insulating sheet.

[0042] The difference between Comparative Example 2 and Example 1 is that no modified polyurethane is added, specifically as follows:

[0043] (1) Add 80g of hydroxylated hexagonal boron nitride, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation, with a melting temperature of 195°C and a screw speed of 150r / min; finally, hot press molding is performed in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0044] The difference between Comparative Example 3 and Example 1 is that hydroxylated hexagonal boron nitride is not added, specifically as follows:

[0045] (1) Add 50g of modified polyurethane, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation, with a melting temperature of 195°C and a screw speed of 150r / min; finally, hot press molding is performed in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0046] The difference between Comparative Example 4 and Example 1 is that when preparing the polyurethane, the piperazine acetic acid-modified polystyrene copolymer is not added, as follows:

[0047] (1) Add 100 g of polyethylene glycol 2000 to a flask, dry and dehydrate, add 26 g of diphenylmethane-4,4'-diisocyanate, introduce nitrogen, heat to 75°C, react for 2 h, and cool to obtain polyurethane.

[0048] (2) Add 50g of polyurethane and 80g of hydroxylated hexagonal boron nitride into a high-speed mixer and blend for 2h at a blending temperature of 80°C. Then, add the blend, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation at a melting temperature of 195°C and a screw speed of 150r / min. Finally, hot-press mold the mixture in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0049] The difference between Comparative Example 5 and Example 1 is that 1-methylpiperazine (CAS No. 109-01-3) is used instead of 2-(piperazin-1-yl)acetic acid when preparing the modified polystyrene copolymer.

[0050] (1) Add 120 mL of chloroform and 8 g of styrene-glycidyl methacrylate copolymer into a flask, stir and then add 3.5 g of 1-methylpiperazine, stir and react at 55 °C for 36 h, pour the solution into ethanol, filter, wash with ethanol, and dry to obtain piperazine-modified polystyrene copolymer.

[0051] (2) Add 100 g of polyethylene glycol 2000 to a flask, dry and dehydrate, add 26 g of diphenylmethane-4,4'-diisocyanate, introduce nitrogen, heat to 75°C, react for 2 h, then add 6 g of piperazine-modified polystyrene copolymer, react for 1 h, cool, and obtain modified polyurethane.

[0052] (3) Add 50g of modified polyurethane and 80g of hydroxylated hexagonal boron nitride into a high-speed mixer and blend for 2h at a blending temperature of 80°C. Then add the blend, 1kg of polystyrene resin and 180g of flame retardant triphenyl phosphate into a twin-screw extruder for granulation at a melting temperature of 195°C and a screw speed of 150r / min. Finally, hot press molding is performed in a flat vulcanizer at a temperature of 190°C and a pressure of 10MPa to obtain an impact-resistant insulating sheet.

[0053] The bending properties are tested according to GB / T 9341-2008. The impact properties are tested according to GB / T 1843-2008. The volume resistivity is tested according to GB / T 1410-2006. The oxygen index is tested according to GB / T 2406.1-2008.

[0054] Table 1 Insulation board performance test

[0055] Bending strength (MPa) <![CDATA[Impact strength (kJ / m 2 )]]> Volume resistivity (Ω·cm) Limiting oxygen index (%) Example 1 64.6 13.2 <![CDATA[1.985×10 15 ]]> 25.3 Example 2 68.0 18.9 <![CDATA[4.768×10 15 ]]> 25.9 Example 3 59.1 21.3 <![CDATA[7.206×10 15 ]]> 27.6 Comparative Example 1 48.8 8.9 <![CDATA[1.422×10 15 ]]> 22.7 Comparative Example 2 46.7 8.1 <![CDATA[1.870×10 15 ]]> 23.4 Comparative Example 3 57.5 11.8 <![CDATA[1.404×10 15 ]]> 23.8 Comparative Example 4 52.0 9.4 <![CDATA[1.791×10 15 ]]> 23.0 Comparative Example 5 56.3 11.4 <![CDATA[1.840×10 15 ]]> 25.1

[0056] The polystyrene insulating board of Comparative Example 1 does not contain modified polyurethane and hydroxylated hexagonal boron nitride, and its bending strength, impact strength, volume resistivity and limiting oxygen index are all low, and its mechanical properties, insulation properties and flame retardancy are poor.

[0057] Modified polyurethane and hydroxylated hexagonal boron nitride are added to the polystyrene insulating board materials of Examples 1, 2, and 3. The modified polyurethane contains polystyrene chain segments and has good compatibility with the polystyrene resin, so that the modified polyurethane has a good toughening effect, which is beneficial to improving the bending strength and impact strength of the polystyrene resin board materials. At the same time, the polystyrene chain segments of the modified polyurethane contain carboxyl groups. During the high-temperature blending process, the carboxyl groups can interact with the hydroxyl groups on the surface of the hydroxylated hexagonal boron nitride through hydrogen bonds and the like, so that the modified polyurethane is coated on the surface of the hexagonal boron nitride, thereby improving the dispersibility of the hexagonal nano boron nitride in the polystyrene resin and further improving the mechanical properties of the board materials. At the same time, the hexagonal nano boron nitride is uniformly dispersed in the board matrix, which is beneficial to improving the volume resistivity and insulation properties. The polystyrene chain segment of the modified polyurethane contains piperazine groups, which can form nitrogen-phosphorus expansion flame retardants with phosphorus-containing flame retardants such as triphenyl phosphate. When burned, it releases non-flammable gases such as nitrogen, promotes the formation of an expanded carbon layer in the board, and has a synergistic flame retardant effect with hexagonal nano boron nitride, which is beneficial to increase the limiting oxygen index of the board and improve the flame retardant properties.

[0058] Comparative Example 2 does not add modified polyurethane, and cannot have a toughening effect on the polystyrene board. In addition, the dispersion of hydroxylated hexagonal boron nitride in the board is poor, which will affect the mechanical properties of the board, and does not improve the insulation properties of the board very well, resulting in low bending strength, impact strength and volume resistivity of the board. In addition, the board does not contain a piperazine structure and cannot form a nitrogen-phosphorus expansion flame retardant with triphenyl phosphate. The limiting oxygen index of the board is low and the flame retardancy is poor.

[0059] Comparative Example 3 does not add hydroxylated hexagonal boron nitride, and the volume resistivity and insulation performance of the plate are low. However, the added modified polyurethane can have a toughening effect, can improve the bending strength and impact strength of the plate, and contains piperazine structure, and forms a nitrogen-phosphorus expansion flame retardant with triphenyl phosphate, and the limiting oxygen index is greater than that of Comparative Example 1. However, no hexagonal nano boron nitride is added, resulting in a lower limiting oxygen index than Example 1.

[0060] In Comparative Example 4, when preparing polyurethane, no piperazine acetic acid-modified polystyrene copolymer was added. The obtained polyurethane did not contain polystyrene molecular chains, had poor compatibility with polystyrene resin, had poor toughening effect, had low bending strength and impact strength, did not contain piperazine structure, could not form nitrogen-phosphorus expansion flame retardant with triphenyl phosphate, had low limiting oxygen index of the board, and had poor flame retardancy.

[0061] In Comparative Example 5, when preparing a modified polystyrene copolymer, 1-methylpiperazine is used instead of 2-(piperazine-1-yl)acetic acid. The obtained modified polyurethane does not contain a carboxyl group, and is difficult to interact with the surface of hydroxylated hexagonal boron nitride, and cannot effectively coat and modify the hexagonal boron nitride, resulting in poor compatibility between the hexagonal boron nitride and the polystyrene resin, affecting the mechanical properties of the plate, and the bending strength and impact strength are lower than those in Example 1.

[0062] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A process for preparing an impact-resistant insulating sheet, characterized in that: The preparation process is: Step A, adding chloroform and styrene-glycidyl methacrylate copolymer into a flask, adding 2-(piperazine-1-yl)acetic acid after stirring, stirring for reaction, pouring the solution into ethanol, filtering, washing, and drying to obtain a piperazineacetic acid modified polystyrene copolymer; Step B, adding polyethylene glycol to a flask, drying and dehydrating, adding a diisocyanate compound, introducing nitrogen, heating to 70-75° C., reacting for 2-3 hours, then adding piperazine acetic acid modified polystyrene copolymer, reacting for 1-1.5 hours, cooling, and obtaining a modified polyurethane; Step C: adding modified polyurethane and hydroxylated hexagonal boron nitride into a high-speed mixer for blending, then adding the blend, polystyrene resin and flame retardant into a twin-screw extruder for granulation, and finally hot-pressing in a flat vulcanizer to obtain an impact-resistant insulating sheet.

2. The process for preparing the impact-resistant insulating sheet material according to claim 1, characterized in that: In the step A, the mass of 2-(piperazine-1-yl)acetic acid is 25-60% of the mass of styrene-glycidyl methacrylate copolymer.

3. The process for preparing the impact-resistant insulating sheet material according to claim 1, characterized in that: In the step A, the reaction is carried out at 50-60° C. for 24-36 hours.

4. The process for preparing the impact-resistant insulating sheet material according to claim 1, characterized in that: In the step B, the masses of the diisocyanate compound and the piperazine acetic acid modified polystyrene copolymer are 18-26% and 6-10% of the mass of the polyethylene glycol respectively; the molecular weight of the polyethylene glycol is 2000.

5. The process for preparing the impact-resistant insulating sheet material according to claim 4, characterized in that: The diisocyanate compound is toluene-2,4-diisocyanate or diphenylmethane-4,4'-diisocyanate.

6. The process for preparing the impact-resistant insulating sheet material according to claim 1, characterized in that: The masses of the modified polyurethane, hydroxylated hexagonal boron nitride and flame retardant are 5-20%, 8-15% and 12-18% of the mass of polystyrene respectively.

7. The process for preparing the impact-resistant insulating sheet material according to claim 6, characterized in that: The flame retardant is triphenyl phosphate or resorcinol bis(diphenyl phosphate).

8. The process for preparing the impact-resistant insulating sheet material according to claim 2, characterized in that: The preparation process of the styrene-glycidyl methacrylate copolymer is as follows: water, styrene, glycidyl methacrylate and sodium dodecylbenzene sulfonate are added into a flask, dibenzoyl peroxide is added after stirring, the mixture is heated to 80-85° C., reacted for 5-7 hours, filtered, washed and dried to obtain the styrene-glycidyl methacrylate copolymer.

9. The process for preparing the impact-resistant insulating sheet material according to claim 8, characterized in that: The masses of the glycidyl methacrylate, sodium dodecylbenzene sulfonate and dibenzoyl peroxide are 12-30%, 2-2.5% and 1.6-2.2% of the mass of styrene respectively.

10. The process for preparing the impact-resistant insulating sheet material according to claim 6, characterized in that: The preparation process of the hydroxylated hexagonal boron nitride is as follows: adding a sodium hydroxide solution with a mass concentration of 150-200 g / L and hexagonal nano boron nitride into a flask, heating to 95-100° C., stirring and condensing and refluxing for 12-18 hours, filtering, washing, and drying to obtain hydroxylated hexagonal boron nitride.

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