A polysiloxane-based flame retardant, a method for preparing the same, and a polycarbonate composite flame retardant material

Abstract

This invention relates to the field of flame retardant materials technology, and provides a polysiloxane-based flame retardant, its preparation method, and a polycarbonate composite flame retardant material. The polysiloxane-based flame retardant includes structures shown in formula (I), formula (II), and formula (III). This application also provides a preparation method and application of the polysiloxane-based flame retardant. The polysiloxane-based flame retardant provided in this application has the advantages of high flame retardant efficiency, low addition amount, and minimal impact on transparency and mechanical properties. Experimental results show that a polycarbonate composite material with 1 wt% of the above-mentioned polysiloxane-based flame retardant can achieve a UL94 V-0 flame retardant rating for a 1.6 mm thick sample, with the limiting oxygen index (LOI) increasing from 26.6% for pure PC to 36.4%, while maintaining essentially the same transparency and mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of flame retardant materials technology, and in particular to a polysiloxane alkyl flame retardant, its preparation method, and a polycarbonate composite flame retardant material. Background Technology

[0002] Bisphenol A polycarbonate (PC), as an important engineering plastic, is widely used in automotive, aerospace, electronic equipment, medical devices, and building materials due to its high transparency, balanced mechanical properties, and thermal stability. At the same time, there is increasing attention on PC materials with superior fire safety and comprehensive performance, especially thin-walled flame-retardant PC. Traditional methods for flame-retardant modification of thin-walled PC materials involve compounding sulfonates, silicones, and fluorinated anti-dripping agents. However, this method not only reduces the material's mechanical properties and transparency, but the perfluorinated compounds also pose environmental hazards. Developing thin-walled flame-retardant PC that combines halogen-free and fluorine-free properties with high transparency is a challenge in this field.

[0003] PC has a limiting oxygen index (LOI) of approximately 24-27% and a UL-94 vertical burning test rating of V-2. However, PC's chemical structure makes it inherently flammable. During combustion, it easily drips, causing flame propagation and intensification, while generating large amounts of heat and toxic fumes, posing a significant threat to personal safety and property. In specialized fields such as electronics and aerospace, PC is required to meet stringent flame retardancy requirements while also maintaining high transparency and excellent mechanical strength, and ideally, using low amounts of flame retardants to reduce costs. Therefore, the development of thin-walled PC composite materials that achieve flame retardancy, transparency, and high mechanical strength with low amounts of flame retardants is urgently needed.

[0004] Based on the different flame-retardant elements, commonly used flame retardants in PC can be classified into halogen-based, silicon-based, phosphorus-based, sulfonate-based, and boron-based types. Phosphorus-based and silicon-based flame retardants require compounding with fluorinated anti-dripping agents to achieve the UL-94 V0 rating for 1.6mm samples. These flame retardants have disadvantages such as high dosage and low flame-retardant efficiency. Sulfonate-based flame retardants can achieve the V0 rating for PC when added alone, with minimal impact on PC transparency. However, the commercially available fluorinated flame retardant potassium perfluorobutyl sulfonate is gradually being phased out due to the toxic fumes produced during combustion. Halogen-free sulfonate flame retardants, on the other hand, are expensive and prone to yellowing.

[0005] Therefore, simply adding a flame retardant to PC cannot achieve a synergistic effect between flame retardant performance and overall performance. It often damages the mechanical properties and transparency of PC. Single-element flame retardant systems can no longer meet the higher requirements for flame retardancy, and multi-element synergistic flame retardancy has become the current application and research trend. For example:

[0006] The literature [Journal of Materials Science, 2021, 56(1): 428-441] synthesized phosphorus-containing incomplete cage-like oligomeric siloxanes (DVPOSSs) flame retardants via hydrolysis-condensation reaction. When the content was 4wt%, the PC / DVPOSSs composite material exhibited good flame retardant properties, but its light transmittance was only 75%. The literature [Polymer Degradation and Stability, 2015, 116: 81-87] synthesized sulfonated polyhedral oligomeric siloxanes (S-POSS) flame retardants via sulfonated octaphenylsiloxanes. When the S-POSS content was only 0.25wt%, the LOI value of the composite material increased to 33.3%, and the UL-94 test achieved a 1.6 mm V-0 rating under the condition of adding anti-dripping agent; however, when the S-POSS content was 1wt%, the fracture strain of the composite material dropped sharply from 96.1% to 40.3%. The literature [Chemical Engineering Journal, 2021, 409:128223] prepared rod-shaped phosphorus-containing metal complex aggregates (CePn) as flame retardants for PC using a one-step solvothermal method. The addition of 4 wt% CePn... n At that time, PC / CeP n It achieves UL-94 V-0 rating and maintains a high transparency of 90.1% and a high tensile strength of 58.1 MPa, but PC / CeP n The elongation at break decreased by 64.7%. Chinese patent CN118878809A discloses a calcium sulfonate-type ionomer flame retardant, prepared by sulfonating polycarbonate and then ion-exchanging it with a metal-source modified component; however, when 2wt% of a sulfonated and 5wt% flame retardant is added, the LOI value of the composite material is 36.5%, and it passes the UL-94 V-0 rating, but its notched impact strength decreases by 37.2%. Chinese patent CN116003800A discloses an organosilicon-based polycarbonate flame retardant, prepared by an addition reaction of raw material components to obtain a polysiloxane containing both aromatic and unsaturated groups with silane-hydrogen bonds in its molecular structure. When added at 2.33wt% and combined with a fluorinated anti-dripping agent, it passes the 1.6mm UL-94 V-0 rating.

[0007] The above studies still struggle to achieve excellent flame retardant properties (1.6mm thin-wall flame retardancy) in polycarbonate while ensuring that it does not lose its original transparency and mechanical properties, under conditions of low addition of flame retardant and no fluorine. Summary of the Invention

[0008] The technical problem solved by this invention is to provide a polysiloxane alkyl flame retardant. The polysiloxane alkyl flame retardant provided in this application can enable polycarbonate composite flame retardant materials to have the advantages of high flame retardant efficiency, good transparency and mechanical properties under low addition conditions.

[0009] In view of this, this application provides a polysiloxane alkyl flame retardant, comprising the structure shown in formula (I), the structure shown in formula (II), and the structure shown in formula (III);

[0010]

[0011] Wherein, G is selected from methyl, vinyl or phenyl; the structure of R1 is as shown in (II1), (II2), (II3), (II4) or (II5); the structure of R2 is as shown in formula (III1);

[0012] a, b, and c are all degrees of polymerization, where a = 20~1500, b = 5~300, and c = 5~500.

[0013]

[0014] X is an alkali metal element.

[0015] In some specific embodiments, the number average molecular weight of the polysiloxane alkyl polymerization inhibitor is 3000~80000.

[0016] This application also provides a method for preparing the aforementioned polysiloxane alkyl flame retardant, comprising the following steps:

[0017] S1. The vacuum-dehydrated siloxane monomer is mixed with the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and reacted. The reactants are then mixed with the solvent to obtain solution A.

[0018] S2. Mix the vacuum-dehydrated siloxane monomer, sulfonate, solvent and photoinitiator and then irradiate with light to obtain solution B;

[0019] S3. Mix solutions A and B with the ring-opening catalyst and react to obtain a polysiloxane alkyl flame retardant.

[0020] In some specific embodiments, in step S1, the vacuum dehydration temperature is 80~120℃ and the time is 1~4h, and / or, the melting temperature of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 120~160℃, and / or, the reaction temperature is 160~200℃ and the reaction time is 2~5h.

[0021] In some specific embodiments, the siloxane monomers mentioned in steps S1) and S2 independently include one or more of methylvinyldichlorosilane, methylvinyldimeth(eth)oxysilane, tetramethyltetravinylcyclotetrasiloxane, and (3-mercaptopropyl)trimethoxysilane; and / or, in step S1, the solvent includes one or both of dichloromethane and tetrahydrofuran; and / or, in step S2, the solvent includes one or more of dichloromethane, tetrahydrofuran, and methanol.

[0022] In some specific embodiments, in step S2, the sulfonate includes one or more of sodium 2-mercaptoethanesulfonate, sodium 2-mercaptobenzimidazole-5-sulfonate, sodium 3-(5-mercapto-1-tetrazolyl)benzenesulfonate, sodium p-styrenesulfonate, and sodium vinylsulfonate; and / or, the photoinitiator includes one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, fluoroborate, diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride, and 2,2-dimethoxy-2-phenylacetophenone; and / or, the illumination is ultraviolet light illumination, and the illumination time is 0.3~1h.

[0023] In some specific embodiments, in step S3, the ring-opening catalyst includes one or more of tetramethylammonium hydroxide, cesium hydroxide, sodium hydroxide, and potassium hydroxide; and / or, the reaction is first carried out at 100~130℃ for 2~4h, and then at 120~150℃ for 0.5~1h.

[0024] In some specific embodiments, in step S1, the molar ratio of the vacuum-dehydrated siloxane monomer to the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 10:(0.4~4.5); and / or, in step S2, the molar ratio of the vacuum-dehydrated siloxane monomer to the sulfonate is 10:(0.2~3).

[0025] This application also provides a polycarbonate composite flame retardant material, comprising polycarbonate and a flame retardant, wherein the flame retardant is the polysiloxane flame retardant described in the above scheme or the polysiloxane flame retardant prepared by the preparation method described in the above scheme.

[0026] In some specific embodiments, the content of the polysiloxane flame retardant is 1~3wt%.

[0027] This application provides a polysiloxane-based flame retardant comprising the structures shown in formula (I), (II), and (III), namely, grafting sulfonate groups and phosphaphenanthrene groups onto the polysiloxane backbone. Thus, the polysiloxane-based flame retardant, under low addition conditions, enables the polycarbonate composite flame retardant material to possess high flame retardant efficiency, as well as good transparency and mechanical properties. Furthermore, the grafting ratio of sulfonate groups to phosphaphenanthrene groups onto the polysiloxane backbone can be precisely controlled, thereby enabling the polycarbonate composite flame retardant material to exhibit optimal performance.

[0028] Furthermore, the polysiloxane flame retardant provided in this application uses a photo-initiated thiol-ene click chemistry reaction to graft sulfonates onto siloxanes. This reaction has the advantages of high reaction efficiency, mild conditions, good selectivity, high yield, and few byproducts. In addition, the optimal molar ratio of sulfonates, monomers containing phosphorus phenanthrene groups, and siloxane monomers can achieve the best flame retardant performance, transparency, and mechanical properties of polycarbonate composite flame retardant materials. Attached Figure Description

[0029] Figure 1 The infrared spectrum of the polysiloxane alkyl flame retardant prepared in Example 1 of this invention;

[0030] Figure 2 The nuclear magnetic resonance spectrum of the polysiloxane alkyl flame retardant prepared in Example 1 of this invention;

[0031] Figure 3 The infrared spectrum of the polysiloxane alkyl flame retardant prepared in Comparative Example 1 of this invention is shown below.

[0032] Figure 4 The nuclear magnetic resonance spectrum of the polysiloxane alkyl flame retardant prepared in Comparative Example 1 of this invention is shown.

[0033] Figure 5 The infrared spectrum of the polysiloxane alkyl flame retardant prepared in Comparative Example 2 of this invention;

[0034] Figure 6 The image shows the nuclear magnetic resonance spectrum of the polysiloxane alkyl flame retardant prepared in Comparative Example 2 of this invention. Detailed Implementation

[0035] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention.

[0036] Given the difficulty in ensuring excellent flame retardant performance of polycarbonate without sacrificing transparency and mechanical properties with low-dosage flame retardants in existing technologies, this application provides a polysiloxane alkyl flame retardant. This flame retardant has sulfonate and phosphaphenanthrene groups grafted onto its polysiloxane backbone. This allows the polysiloxane flame retardant to achieve high flame retardant efficiency, low dosage, and minimal impact on transparency and mechanical properties when applied to polycarbonate composite flame retardant materials. Even with 1 wt% polysiloxane alkyl flame retardant, a 1.6 mm thick sample can achieve a UL94 V-0 flame retardant rating, with the limiting oxygen index (LOI) increasing from 26.6% for pure PC to 36.4%, while maintaining essentially unchanged transparency and mechanical properties. Specifically, this invention discloses a polysiloxane alkyl flame retardant.

[0037]

[0038] Wherein, G is selected from methyl, vinyl or phenyl; the structure of R1 is as shown in (II1), (II2), (II3), (II4) or (II5); the structure of R2 is as shown in formula (III1);

[0039] a, b, and c are all degrees of polymerization, where a = 20~1500, b = 5~300, and c = 5~500.

[0040]

[0041] X is an alkali metal element.

[0042] The polysiloxane-based flame retardant provided in this application has sulfonate groups and phosphaphenanthrene groups grafted onto the polysiloxane backbone. Specifically, the degree of polymerization a of the structure shown in formula (I) is 20-1500, the degree of polymerization b of the structure shown in formula (II) is 5-300, and the degree of polymerization c of the structure shown in formula (III) is 5-300; the number average molecular weight of the polysiloxane-based polymerization inhibitor is 3000-8000. More specifically, the degree of polymerization a of the structure shown in formula (I) is 100-1200, the degree of polymerization b of the structure shown in formula (II) is 30-200, and the degree of polymerization c of the structure shown in formula (III) is 30-200; the number average molecular weight of the polysiloxane-based polymerization inhibitor is 4000-7000. In this application, the degree of polymerization of the structure shown in formula (I), the degree of polymerization of the structure shown in formula (II), and the degree of polymerization of the structure shown in formula (III) can be determined by controlling the molar ratio of the siloxane monomer, the sulfonate monomer, and the phosphenanthrene monomer (DOPO). In (II1), (II2), (II3), (II4), and (II5), X is an alkali metal element, which may be selected from Li, Na, or K. In a specific embodiment, X is selected from Na.

[0043] This application also provides a method for preparing a polysiloxane alkyl flame retardant, comprising the following steps:

[0044] S1. The vacuum-dehydrated siloxane monomer is mixed with the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and reacted. The reactants are then mixed with the solvent to obtain solution A.

[0045] S2. Mix the vacuum-dehydrated siloxane monomer, sulfonate, solvent and photoinitiator and then irradiate with light to obtain solution B;

[0046] S3. Mix solutions A and B with the ring-opening catalyst and react to obtain a polysiloxane alkyl flame retardant.

[0047] In the preparation method of polysiloxane flame retardant, in step S1, the siloxane monomer is first vacuum dehydrated for later use; the vacuum dehydration temperature is 80~120℃ and the time is 1~4h, specifically, the vacuum dehydration temperature is 90~110℃ and the time is 2~3h; at the same time, 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is melted, the melting temperature is 120~160℃, specifically, the melting temperature is 130~140℃. After the above raw materials are prepared, the siloxane monomer and the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are mixed and reacted. The reaction temperature is 160~200℃ and the time is 2~5h. Specifically, the reaction temperature is 170~180℃ and the time is 3~4h. The molar ratio of the vacuum-dehydrated siloxane monomer to the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 10:(0.4~4.5) (i.e., the ratio of silicon-oxygen bonds to sulfonate groups is 40:(0.4~4.5)). Specifically, the molar ratio of the vacuum-dehydrated siloxane monomer to the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 10:(1.5~3.0). In the above process, the siloxane monomer and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide undergo a vinyl addition reaction with pH under high temperature conditions to obtain siloxane I. After the reaction, the obtained product is mixed with a solvent to prepare solution A; the solvent specifically includes one or both of dichloromethane and tetrahydrofuran.

[0048] In step S2, the vacuum-dehydrated siloxane monomer, sulfonate, solvent, and photoinitiator are mixed and then irradiated to obtain solution B. In this step, the siloxane monomer and the sulfonate monomer undergo an addition reaction of vinyl and mercapto groups in the solution under the action of the photoinitiator and under irradiation to obtain siloxane di. The sulfonate is selected from one or more of sodium 2-mercaptoethanesulfonate, (3-mercaptopropyl)trimethoxysilane, sodium 2-mercaptobenzimidazole-5-sulfonate, sodium 3-(5-mercapto-1-tetraazolyl)benzenesulfonate, sodium p-styrenesulfonate, and sodium vinylsulfonate; more preferably, sodium 2-mercaptoethanesulfonate. In some specific embodiments of the present invention, the sulfonate is selected from sodium 2-mercaptoethanesulfonate. The solvent includes one or more of dichloromethane, tetrahydrofuran, and methanol; in specific embodiments, the vacuum-dehydrated siloxane monomer and solvent can be mixed, and the sulfonate and solvent can also be mixed, and then the mixture can be mixed with the photoinitiator. The photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, fluoroborate, diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride, and 2,2-dimethoxy-2-phenylacetophenone; more preferably, 2,2-dimethoxy-2-phenylacetophenone. In some specific embodiments of the present invention, the photoinitiator is selected from 2,2-dimethoxy-2-phenylacetophenone. The molar ratio of the vacuum-dehydrated siloxane monomer to the sulfonate monomer is 10:(0.2~3) (i.e., the ratio of silicon-oxygen bonds to sulfonate groups is 40:(0.2~3)); specifically, the molar ratio of the vacuum-dehydrated siloxane monomer to the sulfonate monomer is 10:(0.5~2); more specifically, the molar ratio of the vacuum-dehydrated siloxane monomer to the sulfonate monomer is 10:(1.0~1.5). In a specific embodiment, the illumination is performed using a 365nm ultraviolet lamp, and the illumination time is 0.3~1h, specifically 0.5~0.8h; the illumination is repeated twice under the above conditions.

[0049] In steps S1 and S2 above, the siloxane monomer is independently selected from one or more of methylvinyl dichlorosilane, methylvinyl dimeth(eth)oxysilane, tetramethyltetravinylcyclotetrasiloxane, and (3-mercaptopropyl)trimethoxysilane. Specifically, the siloxane monomer is independently selected from one of methylvinyl dichlorosilane, methylvinyl dimeth(eth)oxysilane, tetramethyltetravinylcyclotetrasiloxane, and (3-mercaptopropyl)trimethoxysilane. More specifically, the siloxane is selected from tetramethyltetravinylcyclotetrasiloxane. In a specific embodiment, in steps S1 and S2, the siloxane monomer is selected from tetramethyltetravinylcyclotetrasiloxane.

[0050] In step S3, solutions A and B are mixed and reacted to obtain a polysiloxane flame retardant. During this process, siloxane I obtained in step S1 and siloxane II obtained in step S2 undergo ring-opening copolymerization to obtain the polysiloxane flame retardant. In a specific embodiment, solutions A and B are preferably mixed and then rotary evaporated to remove the solvent. The ring-opening catalyst is selected from one or more of tetramethylammonium hydroxide, cesium hydroxide, sodium hydroxide, and potassium hydroxide. Specifically, the ring-opening catalyst is selected from one of methylammonium hydroxide, cesium hydroxide, sodium hydroxide, and potassium hydroxide. More specifically, the ring-opening catalyst is selected from tetramethylammonium hydroxide or sodium hydroxide. The reaction is first carried out at 100-130°C for 2-4 hours, and then at 120-150°C for 0.5-1 hour; specifically, the reaction is first carried out at 110-120°C for 2-3 hours, and then at 130-140°C for 0.6-0.8 hours.

[0051] This application also provides a polycarbonate composite flame retardant material, comprising polycarbonate and a flame retardant, wherein the flame retardant is the polysiloxane flame retardant described in the above scheme.

[0052] In the polycarbonate composite flame retardant material, the content of the polysiloxane alkyl flame retardant in the polycarbonate composite flame retardant material is 1~3wt%.

[0053] This application provides a polysiloxane-based flame retardant, which introduces sulfonate groups and phosphaphenanthrene groups onto the polysiloxane backbone, resulting in excellent flame retardant performance while maintaining good transparency and mechanical properties. Furthermore, the ratio of sulfonate and phosphaphenanthrene groups on the polysiloxane backbone can be precisely controlled, and the optimal ratio between sulfonate, phosphaphenanthrene, and siloxane structures has been determined to achieve optimal flame retardant performance, transparency, and mechanical properties.

[0054] In the preparation of polysiloxane-based flame retardants, this application employs a photo-initiated thiol-ene click chemistry reaction to graft sulfonates onto siloxanes. This reaction boasts advantages such as high reaction efficiency, mild conditions, good selectivity, high yield, and few byproducts. The polysiloxane-based flame retardant provided by this application features high flame retardant efficiency, low addition amount, and minimal impact on transparency and mechanical properties. A polycarbonate composite material with 1 wt% flame retardant can achieve a UL94 V-0 flame retardant rating for a 1.6 mm thick sample, increasing the limiting oxygen index (LOI) from 26.6% for pure PC to 36.4%, while only reducing transparency by approximately 3%, and maintaining mechanical properties essentially identical to pure PC.

[0055] To further understand the present invention, the following detailed description of the polysiloxane alkyl flame retardant, its preparation method, and polycarbonate flame retardant composite material provided by the present invention is provided in conjunction with the embodiments. The scope of protection of the present invention is not limited by the following embodiments.

[0056] The experimental materials used in the following embodiments of the present invention can all be purchased from the market or prepared according to conventional preparation methods well known to those skilled in the art. Some of the materials and their sources are shown in Table 1 below:

[0057] Table 1. List of raw materials used in the following examples and comparative examples.

[0058]

[0059] Example 1

[0060] Polysiloxane grafted with sulfonate and phosphaphenanthrene groups (the molar ratio of cyclosiloxane:phosphaphenanthrene:sulfonate monomers is 10:1.5:1)

[0061] Tetramethyltetravinylcyclotetrasiloxane was dehydrated under vacuum at 80°C for 2 hours and set aside. 2.0 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130°C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180°C and reacted for 4 hours. After cooling, 200 mL of tetrahydrofuran solvent was added to prepare solution A.

[0062] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was dissolved in 200 mL of tetrahydrofuran solvent, and 1.0 g of sodium 2-mercaptoethanesulfonate was dissolved in 200 mL of methanol solvent. The two solutions were mixed and 0.04 g of photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was added. The mixture was irradiated under a 365 nm ultraviolet lamp for half an hour. This process was repeated twice to obtain solution B.

[0063] After thoroughly mixing solution A and solution B, the solvent was removed by rotary evaporation. The solution was then added to a reactor along with 0.2 g of tetramethylammonium hydroxide pentahydrate. The mixture was stirred at 110°C for 3 hours, then stirred at 130°C for half an hour, and finally dried in a vacuum oven at 100°C for 12 hours to obtain the product.

[0064] like Figure 1 and Figure 2 As shown, Figure 1 The above product has an infrared spectrum. Figure 2 The above-mentioned products have nuclear magnetic resonance spectra, derived from... Figure 1 and Figure 2 It can be seen that the product obtained in this embodiment is the polysiloxane alkyl flame retardant (PVSD) of the present invention, with a yield of 95%, and the reaction route is as follows:

[0065]

[0066] Example 2

[0067] Polysiloxane grafted with sulfonate and phosphaphenanthrene groups (the molar ratio of cyclosiloxane:phosphaphenanthrene:sulfonate monomers is 10:0.4:1)

[0068] Tetramethyltetravinylcyclotetrasiloxane was dehydrated under vacuum at 80°C for 2 hours and set aside. 0.5 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130°C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180°C and reacted for 4 hours. After cooling, 200 mL of tetrahydrofuran solvent was added to prepare solution A.

[0069] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was dissolved in 200 mL of tetrahydrofuran solvent, and 1.0 g of sodium 2-mercaptoethanesulfonate was dissolved in 200 mL of methanol solvent. The two solutions were mixed and 0.04 g of photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was added. The mixture was irradiated under a 365 nm ultraviolet lamp for half an hour. This process was repeated twice to obtain solution B.

[0070] After thoroughly mixing solution A and solution B, the solvent was removed by rotary evaporation. The solution was then added to a reactor along with 0.2 g of tetramethylammonium hydroxide pentahydrate. The mixture was stirred at 110°C for 3 hours, then stirred at 130°C for half an hour, and finally dried in a vacuum oven at 100°C for 12 hours to obtain the product.

[0071] The resulting product is the polysiloxane alkyl flame retardant (PVSD) described in this invention, with a yield of 92%, and the reaction route is the same as in Example 1.

[0072] Example 3

[0073] Polysiloxane grafted with sulfonate and phosphaphenanthrene groups (the molar ratio of cyclosiloxane:phosphaphenanthrene:sulfonate monomers is 10:4.5:1)

[0074] Tetramethyltetravinylcyclotetrasiloxane was dehydrated under vacuum at 80°C for 2 hours and set aside. 6.0 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130°C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180°C and reacted for 4 hours. After cooling, 200 mL of tetrahydrofuran solvent was added to prepare solution A.

[0075] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was dissolved in 200 mL of tetrahydrofuran solvent, and 1.0 g of sodium 2-mercaptoethanesulfonate was dissolved in 200 mL of methanol solvent. The two solutions were mixed and 0.04 g of photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was added. The mixture was irradiated under a 365 nm ultraviolet lamp for half an hour. This process was repeated twice to obtain solution B.

[0076] After thoroughly mixing solution A and solution B, the solvent was removed by rotary evaporation. The solution was then added to a reactor along with 0.2 g of tetramethylammonium hydroxide pentahydrate. The mixture was stirred at 110°C for 3 hours, then stirred at 130°C for half an hour, and finally dried in a vacuum oven at 100°C for 12 hours to obtain the product.

[0077] The resulting product is the polysiloxane alkyl flame retardant (PVSD) described in this invention, with a yield of 90%, and the reaction route is the same as in Example 1.

[0078] Example 4

[0079] Polysiloxane grafted with sulfonate and phosphaphenanthrene groups (the molar ratio of cyclosiloxane:phosphaphenanthrene:sulfonate monomers is 10:1.5:0.2).

[0080] Tetramethyltetravinylcyclotetrasiloxane was dehydrated under vacuum at 80°C for 2 hours and set aside. 2.0 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130°C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180°C and reacted for 4 hours. After cooling, 200 mL of tetrahydrofuran solvent was added to prepare solution A.

[0081] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was dissolved in 150 mL of tetrahydrofuran solvent, and 0.2 g of sodium 2-mercaptoethanesulfonate was dissolved in 50 mL of methanol solvent. The two solutions were mixed and 0.01 g of photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was added. The mixture was irradiated under a 365 nm ultraviolet lamp for half an hour. This process was repeated twice to obtain solution B.

[0082] After thoroughly mixing solution A and solution B, the solvent was removed by rotary evaporation. The solution was then added to a reactor along with 0.2 g of tetramethylammonium hydroxide pentahydrate. The mixture was stirred at 110°C for 3 hours, then stirred at 130°C for half an hour, and finally dried in a vacuum oven at 100°C for 12 hours to obtain the product.

[0083] The resulting product is the polysiloxane alkyl flame retardant (PVSD) described in this invention, with a yield of 90%, and the reaction route is the same as in Example 1.

[0084] Example 5

[0085] Polysiloxane grafted with sulfonate and phosphaphenanthrene groups (the molar ratio of cyclosiloxane:phosphaphenanthrene:sulfonate monomers is 10:1.5:3)

[0086] Tetramethyltetravinylcyclotetrasiloxane was dehydrated under vacuum at 80°C for 2 hours and set aside. 2.0 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130°C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180°C and reacted for 4 hours. After cooling, 200 mL of tetrahydrofuran solvent was added to prepare solution A.

[0087] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was dissolved in 200 mL of tetrahydrofuran solvent, and 3.0 g of sodium 2-mercaptoethanesulfonate was dissolved in 200 mL of methanol solvent. The two solutions were mixed and 0.1 g of photoinitiator (2,2-dimethoxy-2-phenylacetophenone) was added. The mixture was irradiated under a 365 nm ultraviolet lamp for half an hour. This process was repeated twice to obtain solution B.

[0088] After thoroughly mixing solution A and solution B, the solvent was removed by rotary evaporation. The solution was then added to a reactor along with 0.2 g of tetramethylammonium hydroxide pentahydrate. The mixture was stirred at 110°C for 3 hours, then stirred at 130°C for half an hour, and finally dried in a vacuum oven at 100°C for 12 hours to obtain the product.

[0089] The resulting product is the polysiloxane alkyl flame retardant (PVSD) described in this invention, with a yield of 91%, and the reaction route is the same as in Example 1.

[0090] Comparative Example 1

[0091] Polysiloxane grafted sulfonate (cyclosiloxane:sulfonate monomer molar ratio of 10:1)

[0092] 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added to a three-necked flask and dehydrated under vacuum at 80 °C for 2 hours. After cooling, 0.1 g of tetramethylammonium hydroxide pentahydrate was added under nitrogen protection with stirring. The reaction temperature was 110 °C, and the reaction was carried out under nitrogen protection for 4 hours. After the reaction was completed, the crude product was washed three times with 100 mL of methanol. After standing for 12 hours, the lower suspension was separated from the separation funnel to obtain a milky white product. After vacuum drying at 60 °C for 1 hour, it was dissolved in 300 mL of tetrahydrofuran and 0.5 g of sodium 2-mercaptoethanesulfonate and 0.02 g of 2,2-dimethoxy-2-phenylacetophenone were added. The mixture was irradiated under ultraviolet light at a wavelength of 365 nm for half an hour. This process was repeated twice to obtain the product.

[0093] like Figure 3 and Figure 4 As shown, Figure 3 The above product has an infrared spectrum. Figure 4 The above-mentioned products have nuclear magnetic resonance spectra, derived from... Figure 3 and Figure 4 It can be seen that the obtained product is the polysiloxane graft sulfonate (PVS-0.1) of this invention, with a yield of 92%, and the reaction route is as follows:

[0094]

[0095] Comparative Example 2

[0096] Polysiloxane grafted with phenanthrene groups (the molar ratio of cyclosiloxane to phenanthrene monomers is 10:3).

[0097] 2.0 g of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide was melted at 130 °C, and then 10.4 g of tetramethyltetravinylcyclotetrasiloxane was added and mixed evenly. The mixture was then heated to 180 °C and reacted for 4 hours. After the reaction was completed, the mixture was cooled to room temperature, and 0.1 g of tetramethylammonium hydroxide pentahydrate was added under nitrogen protection with stirring. The mixture was stirred at 110 °C for 3 hours, then stirred at 130 °C for half an hour, and finally dried in a vacuum oven at 100 °C for 12 hours to obtain the product.

[0098] like Figure 5 and Figure 6 As shown, Figure 5 The above product has an infrared spectrum. Figure 6 The above-mentioned products have nuclear magnetic resonance spectra, derived from... Figure 5 and Figure 6 It can be seen that the obtained product is the polysiloxane grafted with phosphaphenanthrene groups (PVD-2) described in this invention, with a yield of 97%. The reaction route is as follows:

[0099]

[0100] Application Example 1

[0101] (1) Preparation of polycarbonate composite flame retardant materials

[0102] 198 grams of polycarbonate M7027BF was added to a torque rheometer (XSS-300) and 2 grams of flame retardant PVS-0.1 were added. The mixture was prepared by melt mixing at 240°C for 60 rpm for 1 minute and 100 rpm for 5 minutes. The resulting sample was hot-pressed at 240°C for 10 minutes and then cold-pressed at room temperature for 3 minutes to obtain a polycarbonate composite flame retardant material sample of a certain thickness.

[0103] Application Example 2

[0104] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with flame retardant PVD-2; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0105] Application Example 3

[0106] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with the flame retardant PVSD synthesized in Example 1; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0107] Application Example 4

[0108] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with the flame retardant PVSD synthesized in Example 2; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0109] Application Example 5

[0110] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with the flame retardant PVSD synthesized in Example 3; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0111] Application Example 6

[0112] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with the flame retardant PVSD synthesized in Example 4; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0113] Application Example 7

[0114] Referring to the method of Application Example 1, the flame retardant PVS-0.1 in step (1) was replaced with the flame retardant PVSD synthesized in Example 5; the remaining parameters and steps were kept consistent with Application Example 1, and finally a polycarbonate composite flame retardant material sample was prepared.

[0115] Comparison - Business PC

[0116] Commercial polycarbonate material, model PCM7027BF, manufactured by Sinopec Yanshan Petrochemical Company.

[0117] Performance testing

[0118] The polycarbonate composite flame-retardant materials prepared in Examples 1-7 and commercial PC were subjected to vertical burning tests (UL-94), limiting oxygen index tests (LOI), ultraviolet-visible absorption tests (UV-Vis), cantilever beam notched impact and tensile property tests, respectively. The test methods are as follows:

[0119] UL-94: ASTM D3801, for vertical burning tests;

[0120] LOI: ASTM D2863, for limiting oxygen index testing;

[0121] Transmittance and haze testing: based on GB / T 2410 standard;

[0122] Tensile property testing: based on standard GB / T 1040.3-2006;

[0123] Notched impact performance test of cantilever beam: based on standard GB1843-96;

[0124] The results of the above performance tests are shown in Table 2:

[0125] Table 2 Performance data of polycarbonate composite flame retardant materials and commercial PC prepared in application examples

[0126]

[0127] As shown in the table, the polysiloxane alkyl flame retardant prepared in this embodiment, when applied to polycarbonate flame retardant composite materials, exhibits excellent flame retardant performance, good transparency and haze, and mechanical properties comparable to those of existing technologies.

[0128] The above description of the embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0129] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A polysiloxane alkyl flame retardant, comprising the structure shown in formula (I), the structure shown in formula (II), and the structure shown in formula (III); in, G is selected from methyl, vinyl, or phenyl; the structure of R1 is shown as (II1), (II2), (II3), (II4), or (II5); the structure of R2 is shown as (III1); a, b, and c are all degrees of polymerization, where a = 20~1500, b = 5~300, and c = 5~500. X is an alkali metal element.

2. The polysiloxane alkyl flame retardant according to claim 1, characterized in that, The number average molecular weight of the polysiloxane polymerization inhibitor is 3000~80000.

3. The preparation method of the polysiloxane alkyl flame retardant according to claim 1, comprising the following steps: S1. The vacuum-dehydrated siloxane monomer is mixed with the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and reacted. The reactants are then mixed with the solvent to obtain solution A. S2. Mix the vacuum-dehydrated siloxane monomer, sulfonate, solvent and photoinitiator and then irradiate with light to obtain solution B; S3. Mix solutions A and B with the ring-opening catalyst and react to obtain a polysiloxane alkyl flame retardant.

4. The preparation method according to claim 3, characterized in that, In step S1, the vacuum dehydration temperature is 80~120℃ and the time is 1~4h, and / or the melting temperature of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 120~160℃, and / or the reaction temperature is 160~200℃ and the reaction time is 2~5h.

5. The preparation method according to claim 3, characterized in that, The siloxane monomers mentioned in steps S1 and S2 independently include one or more of methylvinyldichlorosilane, methylvinyldimethoxysilane, and tetramethyltetravinylcyclotetrasiloxane; and / or, in step S1, the solvent includes one or two of dichloromethane and tetrahydrofuran; and / or, in step S2, the solvent includes one or more of dichloromethane, tetrahydrofuran, and methanol.

6. The preparation method according to claim 3, characterized in that, In step S2, the sulfonate includes one or more of sodium 2-mercaptoethanesulfonate, sodium 2-mercaptobenzimidazole-5-sulfonate, sodium 3-(5-mercapto-1-tetrazolyl)benzenesulfonate, sodium p-styrenesulfonate, and sodium vinylsulfonate; and / or, the photoinitiator includes one or more of 2-hydroxy-2-methyl-1-phenyl-1-propanone, fluoroborate, diphenyl-(2,4,6-trimethylbenzoyl)phosphorus oxychloride, and 2,2-dimethoxy-2-phenylacetophenone; and / or, the illumination is ultraviolet light illumination, and the illumination time is 0.3~1h.

7. The preparation method according to claim 3, characterized in that, In step S3, the ring-opening catalyst includes one or more of tetramethylammonium hydroxide, cesium hydroxide, sodium hydroxide, and potassium hydroxide; and / or, the reaction is first carried out at 100-130°C for 2-4 hours, and then at 120-150°C for 0.5-1 hours.

8. The preparation method according to claim 3, characterized in that, In step S1, the molar ratio of the vacuum-dehydrated siloxane monomer to the molten 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is 10:(0.4~4.5); and / or, in step S2, the molar ratio of the vacuum-dehydrated siloxane monomer to the sulfonate is 10:(0.2~3).

9. A polycarbonate composite flame retardant material, comprising polycarbonate and a flame retardant, wherein the flame retardant is the polysiloxane flame retardant according to any one of claims 1 to 2 or the polysiloxane flame retardant prepared by the preparation method according to any one of claims 3 to 8.

10. The polycarbonate composite flame-retardant material according to claim 9, characterized in that, The content of the polysiloxane flame retardant is 1~3wt%.

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