Fireproof insulating PC material with high bending strength and preparation method thereof

Abstract

The application relates to the technical field of polycarbonates, and discloses a high-bending-strength fireproof insulating PC material and a preparation method thereof.The fireproof insulating PC material comprises 100 parts by weight of polycarbonate and 2-10 parts by weight of crosslinked polysiloxane modifier; the crosslinked polysiloxane modifier contains hydroxyl groups, imino groups and other groups, forms hydrogen bonds with ester groups of the polycarbonate, and makes the two have good compatibility; meanwhile, the modifier forms a flexible polysiloxane crosslinked particle structure, has a good toughening effect on the polycarbonate, and improves the impact strength and bending strength of the material; and the crosslinked polysiloxane modifier contains sulfonate, triazine and polysiloxane flame-retardant structures, and improves the flame-retardant and fireproof performance of the PC material.

Description

Technical Field

[0001] This invention relates to the field of polycarbonate technology, specifically to a fire-resistant and insulating PC material with high flexural strength and its preparation method. Background Technology

[0002] Polycarbonate has excellent electrical insulation, good dimensional stability, and high heat resistance, and is widely used. Although polycarbonate has certain flame retardant properties, it is still difficult to meet the requirements for applications in the field of fire protection and flame retardancy. Therefore, it is necessary to improve the flame retardant properties of polycarbonate. Common flame retardants for polycarbonate include sulfonate flame retardants, nitrogen and phosphorus flame retardants, and silicon-based flame retardants.

[0003] Polysiloxanes are organosilicon polymers with high flexibility, good flame retardancy, excellent insulation, and strong water resistance, and are widely used in flame retardants and toughening agents. Patent CN116444970B discloses a phosphaphenanthrene / siloxane dual-molecular macromolecular flame-retardant and toughened polycarbonate material. This material uses macromolecules containing phosphaphenanthrene and siloxane structures as flame-retardant and toughening agents, improving the flame retardancy and mechanical properties of polycarbonate. Furthermore, given the poor compatibility between organosilicon polymers such as polysiloxanes and polycarbonate, improving their compatibility can give the material better flexural strength and other properties. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a fire-resistant and insulating PC material with high flexural strength and its preparation method, solving the problems of low flexural strength and poor flame retardancy of polycarbonate materials.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this invention is: a high-flexural-strength fire-resistant insulating PC material and its preparation method, wherein the fire-resistant insulating PC material comprises 100 parts by weight of polycarbonate and 2-10 parts by weight of crosslinked polysiloxane modifier. The preparation method includes:

[0006] (1) Add allylamino polysiloxane and 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to N,N-dimethylformamide, stir, and then add azobisisobutyronitrile dropwise under a nitrogen atmosphere. After stirring and reacting, pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0007] (2) Mix polycarbonate and crosslinked polysiloxane modifier, extrude in a twin-screw extruder, and pelletize to obtain a fireproof and insulating PC material with high flexural strength.

[0008] Preferably, the reaction temperature in (1) is 65-80℃ and the reaction time is 8-12h.

[0009] Preferably, in (1), the mass ratio of allylamino polysiloxane, 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine, and azobisisobutyronitrile is 100:(60-150):(0.5-1.3).

[0010] Preferably, in (2), the temperature of each section of the twin-screw extruder is 220-265℃ and the screw speed is 150-300r / min.

[0011] Preferably, the preparation method of allylamine polysiloxane is as follows: epoxy-propoxy-terminated polydimethylsiloxane and allylamine are added to isopropanol, heated to 40-70℃, reacted for 6-12 hours, and the product after vacuum distillation is added to water. After stirring, the mixture is allowed to stand and separate into layers. The aqueous phase is removed, and the oil phase is dried to remove water, yielding allylamine polysiloxane. The reaction formula is:

[0012]

[0013] Preferably, the mass ratio of epoxy-propylene-terminated polydimethylsiloxane to allylamine is 100:(6.8-8.4).

[0014] Preferably, the preparation method of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine is as follows: 2,4-bis(4-hydroxybenzenesulfonate)-6-chloro-1,3,5-triazine and allylamine are added to 1,4-dioxane, stirred, and then an aqueous solution of sodium carbonate is added. The mixture is heated to 70-85℃ and reacted for 7-10 hours. After vacuum distillation, the product is washed with acetone and dried to obtain 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine. The reaction formula is:

[0015]

[0016] Preferably, the molar ratio of 2,4-bis(4-hydroxybenzenesulfonate)-6-chloro-1,3,5-triazine, allylamine, and sodium carbonate is 1:(1-1.4):(1.2-1.8).

[0017] (III) Beneficial Technical Effects: This invention uses a polysiloxane containing di-terminated allyl groups as a crosslinking agent, which reacts with 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to obtain a crosslinked polysiloxane modifier. This modifier is then used to modify polycarbonate to obtain a fire-resistant and insulating PC material with high flexural strength. The crosslinked polysiloxane modifier contains hydroxyl, imino, and other groups, which form hydrogen bonds with the ester groups of polycarbonate, resulting in good compatibility between the two. At the same time, the modifier forms a flexible polysiloxane crosslinked particle structure, which has a good toughening effect on polycarbonate and improves the impact strength and flexural strength of the material.

[0018] The crosslinking polysiloxane modifier of this invention contains a large number of sulfonate groups, which pyrolyze to generate sulfur dioxide and other substances during combustion. This promotes the isomerization and crosslinking of polycarbonate into char. Simultaneously, the triazine groups and polysiloxane form a nitrogen-silicon flame retardant, further improving the flame retardant and fire-resistant properties of PC materials and significantly increasing the limiting oxygen index. Polycarbonate itself has good electrical insulation properties, while polysiloxane also has high resistivity, giving PC materials excellent insulation performance. Detailed Implementation

[0019] The technical solutions in the embodiments of this application are described clearly and completely below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0020] The following polycarbonate grade LG-DOW PC is sourced from Shenzhen Mait Plastic Products Co., Ltd. The epoxy-propylene-terminated polydimethylsiloxane with a molecular weight of approximately 2000 is sourced from Wuhan Kemike Biomedical Technology Co., Ltd. The diaminopropyl-terminated polysiloxane with a molecular weight of approximately 2000 is sourced from Wuhan Kemike Biomedical Technology Co., Ltd. The polyethylene glycol diacrylate with a molecular weight of approximately 2100 is sourced from Guangdong Fangxin Biotechnology Co., Ltd.

[0021] 2,4-Di(4-hydroxybenzenesulfonate sodium)-6-chloro-1,3,5-triazine was prepared according to the method described in the article "Synthesis of water-soluble triazine derivatives and their application in cellulose modification" in the December 2015 issue of the journal "New Chemical Materials" (Vol. 43, No. 12).

[0022] Add 100 mmol of cyanuric chloride and 200 mmol of sodium 4-hydroxybenzenesulfonate to 350 mL of acetone, stir, and then add 350 mL of an aqueous solution containing 200 mmol of sodium hydroxide. React in an ice-water bath for 2 h, then heat to 40 °C and react for 5 h. After filtration, wash the filter cake with acetone and dry to obtain 2,4-bis(4-hydroxybenzenesulfonate)-6-chloro-1,3,5-triazine, with the structural formula [insert structural formula here].

[0023] Example 1

[0024] (1) Add 200g of epoxypropoxy-terminated polydimethylsiloxane and 16.8g of allylamine to 1L of isopropanol, heat to 40℃, stir and react for 12h, add the product after vacuum distillation to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase to remove water, and obtain allylamine-based polysiloxane.

[0025] (2) Add 150 mmol of 2,4-bis(4-hydroxybenzenesulfonate)-6-chloro-1,3,5-triazine and 150 mmol of allylamine to 800 mL of 1,4-dioxane, stir, add 110 mL of aqueous solution containing 270 mmol of sodium carbonate, heat to 70 °C, stir and react for 7 h, wash the product with acetone after vacuum distillation, dry, and obtain 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine.

[0026] (3) Add 200g of allylamino polysiloxane and 120g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to 2.5L N,N-dimethylformamide. After stirring, add 1g of azobisisobutyronitrile dropwise under a nitrogen atmosphere. Heat to 70℃ and stir for 8h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0027] (4) Mix 5 kg of polycarbonate and 100 g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 200 r / min. Pelletize to obtain fireproof and insulating PC material with high bending strength.

[0028] Example 2

[0029] (1) Add 200g of epoxypropoxy-terminated polydimethylsiloxane and 13.6g of allylamine to 0.8L of isopropanol, heat to 70℃, stir and react for 6h, add the product after vacuum distillation to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase to remove water, and obtain allylamine-based polysiloxane.

[0030] (2) Add 150 mmol of 2,4-bis(4-hydroxybenzenesulfonate)-6-chloro-1,3,5-triazine and 240 mmol of allylamine to 900 mL of 1,4-dioxane. After stirring, add 70 mL of an aqueous solution containing 180 mmol of sodium carbonate. Heat to 85 °C and stir for 10 h. After vacuum distillation, wash the product with acetone and dry to obtain 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine.

[0031] (3) Add 200g of allylamino polysiloxane and 240g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to 3L of N,N-dimethylformamide. After stirring, add 2g of azobisisobutyronitrile dropwise under a nitrogen atmosphere. Heat to 65℃ and stir for 12h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0032] (4) Mix 5 kg of polycarbonate and 200 g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 150 r / min. Pelletize to obtain fireproof and insulating PC material with high bending strength.

[0033] Example 3

[0034] (1) Add 200g of allylamino polysiloxane (prepared according to the method of Example 1) and 300g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine (prepared according to the method of Example 1) to 3L of N,N-dimethylformamide. After stirring, add 2.6g of azobisisobutyronitrile dropwise under a nitrogen atmosphere, heat to 65°C, stir and react for 12h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0035] (2) Mix 5 kg of polycarbonate and 350 g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 300 r / min. Pelletize to obtain fireproof and insulating PC material with high bending strength.

[0036] Example 4

[0037] (1) Add 200g of allylamino polysiloxane (prepared according to the method of Example 1) and 180g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine (prepared according to the method of Example 1) to 2.5L N,N-dimethylformamide. After stirring, add 1.5g of azobisisobutyronitrile dropwise under a nitrogen atmosphere, heat to 80°C, stir and react for 10h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0038] (2) Mix 5kg of polycarbonate and 500g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 200r / min. Pelletize to obtain fireproof and insulating PC material with high bending strength.

[0039] Comparative Example 1 differs from Example 1 in that no cross-linked polysiloxane modifier is added.

[0040] (1) 5 kg of polycarbonate was extruded in a twin-screw extruder at temperatures of 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, with a screw speed of 200 r / min; the extruded material was then pelletized to obtain PC material.

[0041] Comparative Example 2 differs from Example 1 in that the crosslinked polysiloxane modifier is prepared by replacing 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine with styrene.

[0042] (1) Add 200g of allylamino polysiloxane and 120g of styrene to 2.5L N,N-dimethylformamide, stir, add 1g of azobisisobutyronitrile dropwise under nitrogen atmosphere, heat to 70℃, stir for 8h, pour the solution into ethanol, filter, wash with water and ethanol, dry, and obtain crosslinked polysiloxane modifier.

[0043] (2) Mix 5 kg of polycarbonate and 100 g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 200 r / min. Pelletize to obtain PC material.

[0044] Comparative Example 3 differs from Example 1 in that the crosslinking modifier is prepared by using a dual-terminated acrylamide-propyl polysiloxane instead of allylamine-based polysiloxane.

[0045] (1) Bisacrylamidopropyl polysiloxane was prepared according to the method described in the October 2014 issue of the journal "Journal of Textile Research", Volume 35, No. 10, entitled "Synthesis of Acryloyl-terminated Polysiloxane and its Modification of Polyacrylate". 200g of bisacrylamidopropyl polysiloxane and 33g of potassium carbonate were added to 70mL of dichloromethane. 30mL of dichloromethane solution containing 21.6g of acryloyl chloride was added dropwise in an ice-water bath. The mixture was heated to 35℃ and stirred for 3h. The mixture was then extracted and washed successively with 5% sodium bicarbonate solution, water, and saturated sodium chloride solution. The dichloromethane organic phase was dried with anhydrous sodium sulfate and the dichloromethane was removed by vacuum distillation to obtain bisacrylamidopropyl polysiloxane.

[0046] (2) Add 200g of acrylamide-terminated propyl polysiloxane and 120g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to 2.5L N,N-dimethylformamide. After stirring, add 1g of azobisisobutyronitrile dropwise under a nitrogen atmosphere. Heat to 70℃ and stir for 8h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain crosslinked polysiloxane modifier.

[0047] (3) Mix 5 kg of polycarbonate and 100 g of crosslinked polysiloxane modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 200 r / min. Pelletize to obtain fireproof and insulating PC material with high bending strength.

[0048] Comparative Example 4 differs from Example 1 in that the crosslinking modifier is prepared by using polyethylene glycol diacrylate instead of allylamino polysiloxane.

[0049] (1) Add 200g of polyethylene glycol diacrylate and 120g of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine to 2.5L N,N-dimethylformamide. After stirring, add 1g of azobisisobutyronitrile dropwise under a nitrogen atmosphere. Heat to 70℃ and stir for 8h. Pour the solution into ethanol, filter, wash with water and ethanol, and dry to obtain the crosslinking modifier.

[0050] (2) Mix 5 kg of polycarbonate and 100 g of crosslinking modifier, and extrude them in a twin-screw extruder. The temperatures of each section are 220℃, 240℃, 255℃, 265℃, 265℃, and 260℃, and the screw speed is 200 r / min. Pelletize to obtain PC material.

[0051] Flame retardant properties were tested according to GB / T 2406.1-2008 standard. Flexural strength was tested according to GB / T 9341-2008 standard. Impact strength was tested according to GB / T 1843-2008 standard.

[0052] Table 1 Properties of PC materials

[0053]

[0054] The polycarbonate (PC) material in Comparative Example 1 had a low limiting oxygen index, low flexural strength and impact strength, and poor flame retardancy and mechanical strength. In each example, a cross-linked polysiloxane modifier was added. This modifier contains hydroxyl, imino, and other groups, which form hydrogen bonds with the ester groups of polycarbonate, improving the compatibility between the modifier and polycarbonate. Simultaneously, the modifier forms a flexible polysiloxane cross-linked particle structure, which has a good toughening effect on polycarbonate, improving the impact strength and flexural strength of the material. Furthermore, the modifier contains a large number of sulfonate groups, which, during combustion, pyrolyze to generate sulfur dioxide and other substances, promoting the isomerization and cross-linking of polycarbonate into char. At the same time, the triazine groups and polysiloxane form a nitro-silicon flame retardant, further improving the flame retardant and fire-resistant properties of the PC material and significantly increasing the limiting oxygen index.

[0055] In Comparative Example 2, styrene was used instead of 2,4-bis(4-hydroxybenzenesulfonate)-6-allylamino-1,3,5-triazine. The resulting crosslinked polysiloxane modifier did not contain flame-retardant groups such as sulfonate groups and triazine groups, which was not conducive to improving the flame retardancy of polycarbonate and resulted in a lower limiting oxygen index.

[0056] Comparative Example 3 used a dual-terminated acrylamide propyl polysiloxane (without hydroxyl and imino groups) instead of allylamine polysiloxane. The prepared crosslinked polysiloxane modifier had low hydrogen bonding with polycarbonate and poor compatibility, resulting in poor toughening effect of the crosslinked polysiloxane modifier and low flexural strength and impact strength of PC material.

[0057] Comparative Example 4 used polyethylene glycol diacrylate instead of allylamino polysiloxane. The modifier prepared did not contain polysiloxane structure, and the material had lower limiting oxygen index, flexural strength and impact strength.

[0058] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A fire-resistant and insulating PC material with high flexural strength, characterized in that, The fire-resistant and insulating PC material comprises 100 parts by weight of polycarbonate and 2-10 parts by weight of crosslinked polysiloxane modifier; The preparation method of the crosslinked polysiloxane modifier is as follows: allylamino polysiloxane and 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine are added to N,N-dimethylformamide, stirred, and then azobisisobutyronitrile is added dropwise under a nitrogen atmosphere. After stirring and reacting, the solution is poured into ethanol, filtered, washed, and dried to obtain the crosslinked polysiloxane modifier. The mass ratio of allylamino polysiloxane, 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine, and azobisisobutyronitrile is 100:(60-150):(0.5-1.3). The structural formula of the 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine is as follows: ； The preparation method of the allylamine polysiloxane is as follows: add epoxy propoxy-terminated polydimethylsiloxane and allylamine to isopropanol, heat to 40-70℃, react for 6-12h, add the product after vacuum distillation to water, stir and let stand to separate into layers, remove the aqueous phase, dry the oil phase to obtain allylamine polysiloxane. The mass ratio of the epoxy-propylene-terminated polydimethylsiloxane to allylamine is 100:(6.8-8.4).

2. The high flexural strength fireproof and insulating PC material according to claim 1, characterized in that, The reaction temperature is 65-80℃, and the reaction time is 8-12h.

3. The high flexural strength fireproof and insulating PC material according to claim 1, characterized in that, The preparation method of the 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine is as follows: 2,4-bis(4-sulfonate sodium phenoxy)-6-chloro-1,3,5-triazine and allylamine are added to 1,4-dioxane, and after stirring, an aqueous solution of sodium carbonate is added. The mixture is heated to 70-85℃ and reacted for 7-10 hours. After vacuum distillation, the product is washed with acetone and dried to obtain 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine.

4. The high flexural strength fireproof and insulating PC material according to claim 1, characterized in that, In the preparation method of 2,4-bis(4-sulfonate sodium phenoxy)-6-allylamino-1,3,5-triazine, the molar ratio of 2,4-bis(4-sulfonate sodium phenoxy)-6-chloro-1,3,5-triazine, allylamine, and sodium carbonate is 1:(1-1.4):(1.2-1.8).

5. A method for preparing a high flexural strength fire-resistant insulating PC material as described in any one of claims 1-4, characterized in that, The preparation method includes: mixing polycarbonate and crosslinked polysiloxane modifier, extruding in a twin-screw extruder, pelletizing, and obtaining a fire-resistant and insulating PC material with high flexural strength.

6. The method for preparing the high flexural strength fire-resistant insulating PC material according to claim 5, characterized in that, The temperature of each section of the twin-screw extruder is 220-265℃, and the screw speed is 150-300 r / min.

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