Hydroxyl-terminated siloxane oligomer, copolymerized PC and preparation method thereof

Abstract

The invention discloses a hydroxyl-terminated siloxane oligomer, copolymerized PC and a preparation method thereof, the structural formula of the hydroxyl-terminated siloxane oligomer is # imgabs0 #, m + n is greater than or equal to 15, m1 is greater than or equal to 0, and m2 is greater than or equal to 0; r1 and R2 respectively comprise at least one of-H,-CH3 or-C2H5, and R3 comprises at least one of-H,-CH3,-C2H5 or-CN. The copolymerized PC realizes flame retardance and smoke suppression, also gives consideration to inherent high transparency of PC, and has extremely high impact strength.

Description

Technical Field

[0001] The present application relates to the field of polymer materials and polymerization reaction engineering technology, and in particular to a terminal hydroxyl siloxane oligomer, copolymerized PC and a preparation method thereof. Background Art

[0002] Bisphenol A polycarbonate (PC) is the most widely used PC commercial product and the only material with high transparency among the five major engineering plastics. It also has comprehensive comprehensive performance. In addition to traditional applications, it has also shown rapid growth in emerging fields such as high-end sensing, life health and 5G communications in recent years. Although the global PC production capacity has reached 6 million tons / year, my country still relies heavily on imports for special PCs such as electronic equipment, optical components, high-impact protective gear and medical devices, resulting in a significant supply-demand gap and manufacturing risks.

[0003] Since PC contains benzene ring structure in its molecular chain, it has high-temperature carbonization characteristics, but it is still easy to ignite and releases a lot of heat and toxic smoke. When molten drips, it will also cause flame spread and secondary disasters. In specific scenarios, in addition to general flame retardant requirements, it is also required to meet more stringent smoke density and flame spread standards, while maintaining good impact toughness and high transparency of PC.

[0004] At present, PC flame retardancy mainly relies on additive flame retardants, such as halogen, sulfonate, phosphorus, silicone and inorganic nano systems. Among them, sulfonate and silicone are widely used in high-end products due to their high flame retardant efficiency, low smoke emission and less impact on substrate performance, and the two have a synergistic effect when flame retardant PC. However, the technology of adding flame retardants has defects such as poor durability, the need for capacity expansion, deterioration of PC inherent properties, and potential bioaccumulation and environmental toxicity.

[0005] In order to adapt to the trend of high-end materials, researchers began to explore the use of chemical methods to copolymerize flame retardant groups into PC molecular chains (intrinsic flame retardancy). At present, special silicon copolymer PC is developing rapidly in the industry, but most of the current technologies have challenges such as thin-walled products are difficult to reach UL-94V-0 level and silicon blocks affect transparency. Therefore, it is necessary to provide a new impact-resistant, highly transparent, and highly flame-retardant copolymer PC. Summary of the invention

[0006] The present application provides a terminal hydroxyl siloxane oligomer, a copolymerized PC and a preparation method thereof. The copolymerized PC achieves flame retardancy and smoke suppression while taking into account the inherent high transparency of PC and having extremely high impact strength.

[0007] On the one hand, the present application provides a hydroxy-terminated siloxane oligomer, the structural formula of which is:

[0008]

[0009] Wherein, m+n≥15, m1≥0, m2≥0; R1 and R2 respectively include at least one of -H, -CH3 or -C2H5, and R3 includes at least one of -H or -CH3 or -C2H5 or -CN.

[0010] The present application also provides a method for preparing a hydroxy-terminated siloxane oligomer, comprising:

[0011] Octa-substituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane are polymerized to form polysiloxane oligomer DMS-NH2; and amino groups in the DMS-NH2 are subjected to aldehyde-amine condensation reaction with aldehyde groups in aromatic aldehydes to generate the terminal hydroxyl siloxane oligomer DMS-Schiff.

[0012] In some embodiments of the present application, the polymerization reaction is carried out under the action of a first catalyst, which includes at least one of (Ph3P)4Pd, (Ph3P)2PdCl2, [RhCl(CO)2]2, (Ph3P)2NiCl2, chloroplatinic acid or tetramethylammonium hydroxide pentahydrate, and the molar percentage of the first catalyst accounts for 0.01 to 4.5% of all reactants in the polymerization reaction.

[0013] In some embodiments of the present application, the polymerization reaction is carried out in a first solvent, which includes any two of water, ethanol, N-N'-dimethylformamide, acetone, chloroform and dimethyl sulfoxide, and the volume ratio of the two solvents in the first solvent is 3:1 to 1:4.

[0014] In some embodiments of the present application, the polymerization reaction of octa-substituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane to form a polysiloxane polymer includes: subjecting octa-substituted cyclotetrasiloxane, 3-aminopropylmethyldiethoxysilane, the first catalyst and the first solvent to a reflux reaction at a temperature of 65 to 90° C. for a first time, wherein the first time is 15 to 60 minutes; stirring at an oil bath temperature of 80 to 150° C. until the system becomes viscous, removing the first catalyst, and performing a rotary evaporation process to remove low-boiling impurities to obtain the polysiloxane polymer DMS-NH2.

[0015] In some embodiments of the present application, the aromatic aldehyde is an aromatic aldehyde in which the aldehyde group and R3 are para-substituted.

[0016] On the other hand, the present application provides a copolymer PC having the structural formula:

[0017]

[0018] Among them, m+n≥15, m1≥0, m2≥0; R1 and R2 respectively include at least one of -H, -CH3 or -C2H5, and R3 includes at least one of -H or -CH3 or -C2H5 or -CN; x+y+z≥70, x≥0, y≥0, z=m+n; 1%≤z / (x+y+z)≤65%.

[0019] In some embodiments of the present application, the The mass percentage content of the group is 0.5 to 48%, The mass percentage content of the group is 0.2 to 3‰.

[0020] The present application also provides a method for preparing copolymerized PC, comprising: using bisphenol A (BPA), diphenyl carbonate (DPC), disodium 3,6-dihydroxy-2,7-naphthalene disulfonate (DN-SO3Na) and the terminal hydroxyl siloxane oligomer DMS-Schiff as raw materials, performing a melt polycondensation reaction to obtain the copolymerized PC.

[0021] In some embodiments of the present application, the melt polycondensation reaction includes a first reaction stage and a second reaction stage, wherein the first reaction stage is subjected to a temperature condition of 140 to 270°C for 1 to 6 hours to complete the ester exchange process; and the second reaction stage is subjected to a temperature condition of 250 to 320°C for 0.5 to 1 hour to complete the condensation polymerization and functional block copolymerization process.

[0022] In some embodiments of the present application, the melt polycondensation reaction is carried out under the action of a second catalyst, and the second catalyst includes at least one of tri-n-butylamine, tetrabutylammonium hydroxide and tetrabutylammonium chloride.

[0023] In some embodiments of the present application, the molar ratio of BPA:DPC:DMS-Schiff:DN-SO3Na is: 1:2:(0.02-0.99):(0.00005-0.005).

[0024] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0025] (1) Different from blending modification, compared with traditional PC composite materials, the copolymerized PC prepared by this application based on copolymerization technology has better consistency and stability. At the same time, the synthesis method is simple and controllable, so it has higher potential for industrialization and achievement transformation;

[0026] (2) Through reasonable structural design and block phase size control, the siloxane-naphthalene sulfonate copolymer PC material prepared in this application breaks through the "pain point" of the existing silicon copolymer PC series products that are difficult to maintain high transparency;

[0027] (3) This application, by virtue of the toughening, anti-melting and smoke suppression and toxicity reduction effects of functionalized polysiloxane, combined with the specific and efficient flame retardant advantages of sulfonates on PC (the content of sulfonates in copolymerized PC is as low as one ten-thousandth of an order of magnitude), ingeniously endows PC with high transparency, impact resistance, low smoke and flame retardancy, which are difficult to achieve at the same time, thereby obtaining a polymer product with higher added value, and at the same time greatly expanding the scope and scenarios of application;

[0028] (4) This application adopts appropriate research methods in the gas phase and condensed phase, respectively, integrates the free radical capture effect and the "two-phase" conclusion, and supplements and improves the flame retardancy and thermal degradation mechanism of silicone and sulfonate systems in PC and its copolymers;

[0029] (5) This application establishes a structure-comprehensive performance relationship model of siloxane-naphthalene sulfonate copolymer PC through the corresponding analysis of microscopic morphology-phase behavior and macroscopic performance (impact resistance and transparency), which has both scientific significance and practical application value in the field of high-performance PC. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The following figures describe in detail the exemplary embodiments disclosed in this application. The same reference numerals represent similar structures in several views of the drawings. Those skilled in the art will understand that these embodiments are non-limiting, exemplary embodiments, and the drawings are only for the purpose of illustration and description, and are not intended to limit the scope of this application. Other embodiments may also accomplish the inventive intent in this application. It should be understood that the drawings are not drawn to scale.

[0031] in:

[0032] Figure 1 The hydrogen nuclear magnetic resonance spectra of DMS-NH2 and DMS-Schiff prepared in Example 1 of the present application ( 1 H-NMR) spectra;

[0033] Figure 2 The carbon NMR spectra of the SS-co-PC materials prepared in Examples 6 to 9 of the present application and the commercial products in Comparative Examples 1 and 2 ( 13 C-NMR) spectra;

[0034] Figure 3 The infrared (FT-IR) spectra of the DMS-Schiff, SS-co-PC materials and commercial pure PC prepared in Examples 1 and 7 of the present application and Comparative Example 1 are shown. DETAILED DESCRIPTION

[0035] The following description provides specific application scenarios and requirements of the present application, with the purpose of enabling those skilled in the art to make and use the content in the present application. It will be apparent to those skilled in the art that various local modifications to the disclosed embodiments are apparent, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0036] On the one hand, the present application provides a hydroxy-terminated siloxane oligomer, the structural formula of which is:

[0037]

[0038] Among them, m+n≥15, m1≥0, m2≥0;

[0039] R1 and R2 are substituents on the main chain of the polysiloxane, respectively including at least one of -H, -CH3 or -C2H5, and are used to adjust the content of silicon in the terminal hydroxyl siloxane oligomer.

[0040] R3 is a substituent on the aromatic aldehyde, including at least one of -H or -CH3 or -C2H5 or -CN, which is used to adjust the content of silicon in the terminal hydroxyl siloxane oligomer, as well as the charring, flame retardant and smoke suppression and toxicity reduction properties of the terminal hydroxyl siloxane oligomer. In one embodiment of the present application, m is 8, n is 7, R1 is -CH3, R2 is -C2H5, and R3 is -C2H5.

[0041] The present application also provides a method for preparing a hydroxy-terminated siloxane oligomer (DMS-Schiff), comprising:

[0042] Step S1: polymerizing octasubstituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane to form a polysiloxane oligomer DMS-NH2;

[0043] Step S2: allowing the amino group in the DMS-NH2 to undergo an aldehyde-ammonia condensation reaction with the aldehyde group in the aromatic aldehyde to generate the terminal hydroxyl siloxane oligomer DMS-Schiff.

[0044] In some embodiments of the present application, the reaction formula for preparing the hydroxy-terminated siloxane oligomer is:

[0045]

[0046] Among them, octasubstituted cyclotetrasiloxane wherein R1 includes at least one of -H, -CH3 or -C2H5; 3-aminopropylmethyldiethoxysilane wherein R2 includes at least one of -H, -CH3 or -C2H5.

[0047] In some embodiments of the present application, the polymerization reaction is carried out under the action of a first catalyst, which is used to accelerate the reaction rate. The first catalyst includes at least one of a precious metal compound such as (Ph3P)4Pd, (Ph3P)2PdCl2, [RhCl(CO)2]2, (Ph3P)2NiCl2, chloroplatinic acid or an organic base such as tetramethylammonium hydroxide pentahydrate. In the polymerization reaction, the molar percentage of the first catalyst accounts for 0.01 to 4.5% of all reactants, for example, 0.05%, 0.1%, 0.5%, 1.5% and 3.5%, etc.

[0048] In some embodiments of the present application, the polymerization reaction is carried out in a first solvent, the first solvent includes any two of water, ethanol, N-N'-dimethylformamide, acetone, chloroform and dimethyl sulfoxide, and the volume ratio of the two solvents in the first solvent is 3:1 to 1:4, that is, the two solvents contained in the first solvent can be arbitrarily proportioned within the volume ratio range. The first solvent is used to dissolve the octa-substituted cyclotetrasiloxane, 3-aminopropylmethyldiethoxysilane and the catalyst.

[0049] Specifically, the method for forming the polysiloxane oligomer DMS-NH2 includes: taking octa-substituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane as starting reactants, adding a first catalyst, and performing a polymerization reaction in a first solvent, wherein the polymerization reaction also includes a hydrolysis step and a ring-opening step, wherein the ring-opening step is a ring-opening reaction of the Si-O bond in the octa-substituted cyclotetrasiloxane, and the hydrolysis step is a hydrolysis reaction of the ethoxy group in the 3-aminopropylmethyldiethoxysilane.

[0050] In some embodiments of the present application, the polymerization reaction includes: subjecting octasubstituted cyclotetrasiloxane, 3-aminopropylmethyldiethoxysilane, the first catalyst and the first solvent to a reflux reaction at a temperature of 65 to 90° C. for a first time, wherein the first time is 15 to 60 minutes; continuously stirring under an oil bath condition of 80 to 150° C. until the system becomes viscous, heating the system to a temperature higher than the evaporation temperature of the first catalyst to remove the first catalyst, and performing a rotary evaporation process (reduced pressure distillation) to remove low-boiling impurities to obtain the DMS-NH2.

[0051] Then, step S2 is performed to cause the amino group in the DMS-NH2 to undergo an aldehyde-ammonia condensation reaction with the aldehyde group in the aromatic aldehyde to generate the hydroxy-terminated siloxane oligomer. In some embodiments of the present application, the aromatic aldehyde is an aromatic aldehyde with an aldehyde group and R3 substituted in the para position, which is used to construct a Schiff base structure on the DMS-Schiff side chain.

[0052] Specifically, the macromolecular reaction is carried out with the second solvent as the medium, DMS-NH2 and aromatic aldehydes with different substituents are subjected to aldehyde-ammonia condensation reaction, and then flocculation and rotary evaporation are performed to obtain the DMS-Schiff. The second solvent includes at least one of dichloromethane, dichloroethane, toluene and cyclohexane.

[0053] In some embodiments of the present application, the temperature of the macromolecular reaction is controlled at room temperature to 45°C, the third solvent used in the flocculation process includes at least one of methanol, ethanol, and isopropanol, and the third solvent is a poor solvent for the DMS-Schiff. The reaction temperature of the rotary evaporation process is 50 to 120°C, and the rotary evaporation is performed until there is no liquid substance in the rotary evaporation bottle to completely remove the solvent used in the reaction.

[0054] The DMS-Schiff provided in the embodiments of the present application is an important functional block (siloxane block) of siloxane-naphthalene sulfonate copolymer polycarbonate, which plays a role in improving the low-temperature toughness and impact resistance of the final material and inhibiting the smoke release rate and release amount during combustion. At the same time, the micro-domain size and phase behavior of the siloxane block in the copolymer PC will play a decisive role in the transparency of the final material; in addition, the difference in substituents R1, R2, and R3 will affect the silicon content, fluidity at high temperature and carbon-forming performance of the siloxane block, thereby affecting the comprehensive performance of the copolymer PC.

[0055] On the other hand, the present application provides a copolymer PC having the structural formula:

[0056]

[0057] Among them, m+n≥15, m1≥0, m2≥0; R1 and R2 respectively include at least one of -H, -CH3 or -C2H5, and R3 includes at least one of -H or -CH3 or -C2H5 or -CN; x+y+z≥70, x≥0, y≥0, z=m+n; 1%≤z / (x+y+z)≤65%.

[0058] In some embodiments of the present application, the The mass percentage content of the group is 0.5 to 48%, The mass percentage content of the group is 0.2 to 3‰.

[0059] The present application also provides a method for preparing a copolymerized PC, comprising: using bisphenol A (BPA), diphenyl carbonate (DPC), disodium 3,6-dihydroxy-2,7-naphthalene disulfonate (DN-SO3Na) and the terminal hydroxyl siloxane oligomer as raw materials, performing a melt polycondensation reaction to obtain the copolymerized PC. The copolymerized PC is a siloxane-naphthalene sulfonate copolymerized PC, which is abbreviated as SS-co-PC in the present application specification.

[0060] In some embodiments of the present application, the reaction formula of the method for preparing the copolymerized PC is:

[0061]

[0062] In some embodiments of the present application, the melt polycondensation reaction is carried out under the action of a second catalyst, and the second catalyst includes at least one of tri-n-butylamine, tetrabutylammonium hydroxide and tetrabutylammonium chloride. Further, the melt polycondensation reaction is carried out under an inert atmosphere, and the gas forming the inert atmosphere includes nitrogen, argon, etc.

[0063] In some embodiments of the present application, tri-n-butylamine is used as a catalyst, and under the protection of an inert atmosphere, bisphenol A (BPA), diphenyl carbonate (DPC), 3,6-dihydroxy-2,7-naphthalene disulfonic acid disodium (DN-SO3Na) and the DMS-Schiff are mixed and subjected to a melt polycondensation reaction, and then the product of the melt polycondensation reaction is cooled, dissolved, flocculated, filtered, and dried to obtain the SS-co-PC. The transesterification reaction between BPA and DPC can obtain a polycarbonate block, and DN-SO3Na and DMS-Schiff are both bifunctional comonomers / oligomers containing hydroxyl groups, which can be gradually condensed and polymerized with DPC and BPA and remove water or phenol.

[0064] The embodiment of the present application can form organosilicon-sulfonate copolymer PC with different block components by controlling the usage ratio of bisphenol A (BPA), diphenyl carbonate (DPC), disodium 3,6-dihydroxy-2,7-naphthalene disulfonate (DN-SO3Na) and the DMS-Schiff, the reaction time of the melt polycondensation reaction, the reaction temperature, the reaction pressure and atmosphere, the reaction medium, the type and addition amount of the catalyst, whether to remove the small molecules generated in the condensation, and other process conditions, and realize the regulation of the molecular weight and distribution of the copolymer product.

[0065] In some embodiments of the present application, the melt polycondensation reaction includes a first reaction stage and a second reaction stage, wherein the first reaction stage is reacted at a temperature of 140 to 270° C. for 1 to 6 hours to complete the ester exchange process between BPA and DPC; the second reaction stage is reacted at a temperature of 250 to 320° C. for 0.5 to 1 hour to complete the condensation polymerization (polycondensation) and the functional block copolymerization process.

[0066] In some embodiments of the present application, the molar ratio of BPA:DPC:DMS-Schiff:DN-SO3Na is: 1:2:(0.02-0.99):(0.00005-0.005), for example: 1:2:0.5:0.0005, or 1:2:0.09:0.001, etc.

[0067] The dissolving solvent for dissolving the product of the melt polycondensation reaction includes any one of dichloromethane, tetrahydrofuran, and N,N'-dimethylformamide, and the solvent is a good solvent for SS-co-PC materials. The flocculation solvent for flocculating the product of the melt polycondensation reaction includes but is not limited to poor solvents for SS-co-PC materials such as methanol, ethanol, and isopropanol. The drying operation of drying the product of the melt polycondensation reaction is carried out in a blast oven, the temperature is controlled at 75-120°C, the time is controlled at 6-18h, and the SS-co-PC is obtained after drying.

[0068] In the SS-co-PC material provided in the embodiment of the present application, the silicone block can give PC better impact toughness, dynamic mechanical properties at low temperature and smoke suppression and toxicity reduction effects. The design requires high silicon content, good fluidity at high temperature, and appropriate modification of flame retardant functional side groups; the sulfonate component is a "specific and efficient" flame retardant in the PC matrix, mainly used to improve the flame retardant efficiency and anti-melting droplet properties of PC, and based on the π-π effect, aromatic sulfonates that are not easy to phase separate from PC are selected. At the same time, as a block copolymer, the invention has better consistency and stability than blended composite materials.

[0069] In some embodiments of the present application, the SS-co-PC can also be processed and formed, and the processing and forming method includes: drying the SS-co-PC material to prevent the polar block from absorbing water and causing degradation, bubble generation, yellowing, etc. of the material after processing, and then melt-kneading the SS-co-PC to prepare a copolymer material with a more uniform microphase size distribution, and preparing a standard sample by a hot pressing molding process for testing.

[0070] In some embodiments of the present application, the drying treatment temperature is 65-110°C, which can be adjusted according to the relative content of the silicone block in the SS-co-PC, and the drying time is 16-40h; the melt mixing temperature is controlled at 220-245°C, and the time is controlled at 6-14min. In the melt mixing process, the rotation speed of the rotor in the reaction chamber is 50-85rpm.

[0071] In some embodiments of the present application, the temperature of the hot pressing process is controlled at 190-240° C., the holding time is 1-6 min, and the holding pressure is controlled at 15-20 MPa.

[0072] The comprehensive performance of the SS-co-PC material provided in the embodiment of the present application is related not only to the synthesis conditions and component content, but also to the above-mentioned processing and molding processes, and it is necessary to control the process parameters of the melt mixing and hot pressing molding.

[0073] Example 1

[0074] Preparation of DMS-Schiff:

[0075] 100g of octamethylcyclotetrasiloxane, 14g of 3-aminopropylmethyldiethoxysilane, 0.08g of tetramethylammonium hydroxide pentahydrate (catalyst), 3g of deionized water and 1.2g of dimethyl sulfoxide (DMSO) were added to a three-hole flask with mechanical stirring, and the reaction system was refluxed and stirred at 90°C for 4h, and then the obtained mixture was slowly stirred at 120°C in an oil bath for 24h. Finally, the reaction system was heated to 140°C and maintained for 30min to remove the catalyst, and the components such as low-boiling solvents were completely removed at 80°C to obtain DMS-NH2. 3.5g of the above DMS-NH2 and benzaldehyde (the molar ratio of -NH2 and -CHO was controlled to be 1:1) were added to 20mL of dichloromethane for aldehyde-ammonia condensation. After stirring the reaction at room temperature for 4h, methanol was used for flocculation and DMS-Schiff was obtained by rotary evaporation at 80°C.

[0076] Example 2

[0077] The difference between this embodiment and embodiment 1 is that the catalyst is rhodium (1,5-cyclooctadiene) chloride dimer, namely [RhCl(CO)2]2.

[0078] Example 3

[0079] The difference between this embodiment and embodiment 1 is that octamethylcyclotetrasiloxane is replaced by 1,3,5,7-tetramethylcyclotetrasiloxane.

[0080] Example 4

[0081] The difference between this embodiment and embodiment 1 is that benzaldehyde is replaced by p-methylbenzaldehyde (ie, -R3 is -CH3).

[0082] Example 5

[0083] The only difference between this embodiment and embodiment 1 is that in embodiment 5, the polymerization reaction starter is replaced by 1,3,5,7-tetramethylcyclotetrasiloxane instead of octamethylcyclotetrasiloxane, and the aromatic aldehyde used in the aldehyde-ammonia condensation reaction is p-tolualdehyde (ie, -R3 is -CH3).

[0084] Example 6

[0085] Preparation of PC copolymer:

[0086] 0.1 mol BPA, 0.2 mol DPC, 0.005 mol DMS-Schiff in Example 1 and 0.15 mmol DN-SO3Na as comonomer / block were added to the reactor, and 10 -3Tetrabutylammonium hydroxide in the mmol range was used as a catalyst, and then the temperature was raised to 180°C for 6 hours under argon protection to complete the ester exchange, and then the pressure of the reaction system was reduced to 125Pa to continuously precipitate small molecules, and the temperature was raised to 260°C for 0.5 hours to complete the condensation polymerization reaction. Finally, the reactants were cooled to room temperature, dissolved in dichloromethane, and flocculated with ethanol. After filtration, they were dried at 100°C for 7 hours to obtain the final product SS-co-PC.

[0087] Example 7

[0088] The difference between this embodiment and embodiment 6 is that the added amount of DMS-Schiff is 0.010 mol.

[0089] Example 8

[0090] The difference between this embodiment and embodiment 6 is that the added amount of DMS-Schiff is 0.015 mol.

[0091] Example 9

[0092] The difference between this embodiment and embodiment 6 is that the added amount of DMS-Schiff is 0.020 mol.

[0093] Example 10

[0094] The difference between this embodiment and embodiment 7 is that the DMS-Schiff used is obtained from embodiment 3.

[0095] Embodiment 11

[0096] The difference between this embodiment and embodiment 7 is that the DMS-Schiff used is obtained from embodiment 4.

[0097] Example 12

[0098] The difference between this embodiment and embodiment 7 is that the DMS-Schiff used is obtained from embodiment 5.

[0099] Application Example 1

[0100] In this application example, the SS-co-PC in Example 6 is processed and molded to prepare a standard sample / product of high-performance copolymerized PC. The preparation method includes the following steps:

[0101] First, the material was dried in a blast oven at 80°C for 20 hours to completely remove moisture, and then the material was placed in a torque rheometer for melt processing (temperature 225°C, rotation speed 60rpm, time 8min). The processed material was then placed in different molds and hot pressed for 3 minutes at 230°C and 18MPa to obtain standard specimens / products.

[0102] Application Example 2

[0103] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from Example 7.

[0104] Application Example 3

[0105] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from Example 8.

[0106] Application Example 4

[0107] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from example 9.

[0108] Application Example 5

[0109] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from example 10.

[0110] Application Example 6:

[0111] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from example 11.

[0112] Application Example 7:

[0113] The difference between this application example and application example 1 is that the SS-co-PC material used is obtained from Example 12.

[0114] Application Comparative Example 1

[0115] The difference between this comparative application example and application example 1 is that SS-co-PC is replaced by non-copolymerized pure PC with a brand number of K-1300 provided by Teijin Limited of Japan.

[0116] Application Comparative Example 2

[0117] The difference between this comparative application example and application example 2 is that SS-co-PC is replaced by siloxane copolymer PC with the brand name EXL9330 provided by Saudi Basic Industries Corporation (Sabic).

[0118] Depend on Figure 1 , Figure 2 , Figure 3 The NMR and IR spectra show that the prepared DMS-Schiff and SS-co-PC materials have correct structures and polysiloxane block and copolymer PC materials have been successfully synthesized. 13The characteristic peak area in C-NMR shows that the proportions of polysiloxane blocks in the SS-co-PC materials prepared in Examples 6 to 9 are 5.02%, 9.26%, 14.31% and 20.28, respectively. The proportion of polysiloxane blocks in the commercial grade EXL9330 (comparative example 2) is 11.27%, which is between Example 7 and Example 8 of the present application. The following will compare the performance of application examples 1-7 of the present invention with application examples 1 and 2 to illustrate the advantages of the materials in the examples of the present application. Among them, Figure 1 and Figure 2 The horizontal axis Chemical Shift refers to the movement of the nuclear magnetic resonance absorption position caused by the shielding effect of electrons, and the vertical axis Intensity refers to the resonance signal intensity of different groups. Figure 2 SS-co-PC5, SS-co-PC9, SS-co-PC14, SS-co-PC20, as well as K1300 and EXL9330 are the test results of PC polymer materials prepared in Example 6, Example 7, Example 8, Example 9 and Comparative Example 1 and Comparative Example 2, respectively.

[0119] Figure 3 The horizontal axis Wavenumber (wavelength) refers to the distance that the light wave propagates in one vibration cycle, and the vertical axis Transmittance (transmittance) refers to the ability of light to pass through the medium. Figure 3 SS-co-PC9, DMS-Schiff and K-1300 are the test results of PC polymer materials prepared in Example 7, Example 1 and Comparative Example 1 respectively.

[0120] The SS-co-PC materials prepared in Application Examples 1-7 and Application Comparative Examples 1-2 were subjected to three flame retardant performance evaluation tests: limiting oxygen index (LOI), UL-94 vertical burning rating, and cone calorimetry test, and the methods are as follows:

[0121] (1) Limiting oxygen index (LOI) test: Tested on QinSun-F101 limiting oxygen index instrument according to ISO-4589 standard, sample size: 130×6.5×3mm 3 , 5 samples were tested for each group of materials, and the average value was taken. The flammability of the materials was evaluated with reference to the test data. The test results are shown in Table 1.

[0122] (2) UL-94 vertical burning grade: tested in accordance with IEC 60695-11-10 standard on a CZF-3 vertical burning tester, specimen size: 130×13×0.8mm 3 (Thin-walled samples), each material was tested three times to determine the final grade. The test results are shown in Table 1.

[0123] (3) Cone calorimetry (CONE) test: The test was conducted on a FTT cone calorimeter according to ISO-5660 standard, with an irradiation intensity of 35 kW / m 2 , Sample size: 100×100×3mm 3 , 3 samples were tested for each material, and the average value was taken to evaluate the heat and smoke release behavior of the material. The test results are shown in Table 1.

[0124] As can be seen from Table 1, under the combined effect of functional units and blocks, the limiting oxygen index of the copolymerized PC material can be increased from 23.9% of pure PC to 31.4% with only 5% siloxane blocks and 1 / 10,000 naphthalene sulfonate copolymer unit content (Application Example 1), and it reaches the V-1 level in the vertical combustion experiment, but there is still a molten drop phenomenon, which is easy to cause secondary disasters; with the increase of siloxane blocks, the LOI of the SS-co-PC material gradually increases. When the polysiloxane content reaches 20%, the LOI of the SS-co-PC material reaches an astonishing 34%, and the sensitivity to oxygen is greatly reduced. When the polysiloxane content is above 5%, the UL-94 vertical combustion grade of all SS-co-PC materials can reach the strict V-0 level, showing excellent self-extinguishing performance from the fire, and there is no molten droplets, which effectively reduces the risk of flame spread.

[0125] Table 1: Flame retardant properties of materials in application examples 1-7 and application comparative examples 1-2

[0126]

[0127] In Table 1, PHRR: peak heat release rate; THR: total heat release; PSPR: peak smoke release rate; TSR: total smoke release; LOI: limiting oxygen index; UL-94 grade is determined by the vertical burning method.

[0128] Cone calorimetry is the best simulation method to reflect the combustion behavior of polymers under real fire conditions. Thermal radiation and the release of toxic smoke are the two main culprits causing fire deaths and injuries. Peak heat release rate (PHRR) and total heat release (THR) are important parameters reflecting heat release, while peak smoke release rate (PSPR) and total smoke release (TSP) are important parameters reflecting smoke release. Compared with non-copolymerized PC, SS-co-PC has a significant reduction in both rate and total amount of heat release and smoke release, which can be attributed to the condensed phase free radical capture effect of naphthalene sulfonate, the smoke suppression and toxicity reduction effect of the siloxane block, and the lower combustion thermal radiation.

[0129] Compared with the commercialized siloxane copolymer PC (comparative example 2), all flame retardant indicators of application examples 2 and 3 are more excellent, especially the smoke suppression and toxicity reduction effect in terms of smoke release is more obvious. This can be attributed to the fact that the present invention copolymerizes a trace amount of highly efficient naphthalene sulfonate units into the SS-co-PC material. Firstly, sulfonate is a trace and highly efficient "specific" flame retardant system for PC, which can usually achieve high flame retardancy of PC at the level of one thousandth or even one ten-thousandth. Secondly, siloxane and sulfonate have a significant synergistic flame retardant effect in PC. Therefore, the present invention obtains an advantageous product with high efficiency flame retardancy and smoke suppression through ingenious structural design and technical route.

[0130] The mechanical properties of the materials prepared in Application Examples 1 to 7 and Application Comparative Examples 1 to 2 were tested. The test was divided into three parts: tensile properties, bending properties and impact properties. The method was as follows:

[0131] (1) Tensile property test: The test was carried out on a RTW-10 universal tensile testing machine in accordance with GB / T 1040.1 standard, using dumbbell-shaped specimens (thickness 2 mm, width of the middle parallel part 4 mm), a tensile rate of 5 mm / min, and 8 specimens were tested for each material. The average value was taken to evaluate the yield strength, breaking strength, breaking elongation and other parameters of the composite materials.

[0132] (2) Bending performance test: Tested on a RTW-10 universal mechanical testing machine in accordance with ISO-178 standard, specimen size: 80×10×4mm 3 , 6 specimens were tested for each material, and the average value was taken to evaluate the bending mechanical behavior of the composite material.

[0133] (3) Impact performance test: The test was carried out on a ZBC1400-B impact tester in accordance with ISO-180 standard. The test sample size was 80×10×4mm. 3 (2mm notch), 8 samples were tested for each material, and the average value was taken to evaluate the impact toughness of the composite material.

[0134] Table 2: Mechanical properties of materials of application examples 1-7 and application comparative examples 1-2

[0135]

[0136]

[0137] It can be seen from the data in Table 2 that compared with the pure PC in Application Example 1, the introduction of polysiloxane blocks can significantly improve the impact strength and elongation at break of PC, indicating that the impact toughness and ductility of the copolymerized PC material are greatly improved, and with the increase of the siloxane block content, the toughness and ductility are improved more significantly; while the tensile strength and bending strength of the SS-co-PC material are slightly lower than those of pure PC, which is due to the introduction of elastic macromolecular blocks. With the increase of the siloxane block content, the bending and tensile strength of the copolymer material are reduced more, so the proportion of the siloxane block should be regulated according to the specific usage scenarios and needs. The content of naphthalene sulfonate units is as low as one ten-thousandth, which can be considered to have almost no effect on the mechanical properties of the copolymer material. At the same time, it was found that the performance of application examples 2 and 3 was also better than that of commercialized siloxane copolymerized PC (application comparative example 2, EXL9330), considering the performance of comprehensive tensile, bending and impact properties.

[0138] The transparency and haze of the materials obtained by Application Examples 1 to 7 and Application Comparative Examples 1 to 2 were tested as follows: the samples were hot pressed into a film with a thickness of 0.3 mm in a mold, and the transparency and haze of the materials at an excitation light wavelength of 523 nm were measured using a WGT-S transmittance / haze tester. The visible light transmittance of the materials at wavelengths of 590 nm and 630 nm was measured using a Shimaduzu UV-3600 ultraviolet-visible spectrophotometer. The above tests were conducted in parallel for five times and the average values ​​were taken.

[0139] Table 3: Visible light transmittance and haze of materials of application examples 1 to 7 and application comparative examples 1 to 2

[0140]

[0141]

[0142] In Table 3, the wavelengths of 523 nm, 590 nm, and 630 nm correspond to green light, yellow light, and red light of visible light, respectively, and the haze is the average value under the 523 nm excitation light.

[0143] It can be seen from Table 3 that when the polysiloxane block ratio is 5% and 10%, the visible light transmittance and haze of Application Examples 1, 2, 5, 6, and 7 are slightly reduced compared to pure PC (Application Comparative Example 1), and still maintain good optical transparency, which can greatly expand the application scenarios and maintain the most valuable high transparency of PC materials as much as possible. As the polysiloxane block ratio increases (Application Examples 3 and 4), the visible light transmittance of SS-co-PC materials decreases significantly, and the haze increases more significantly, showing typical translucent characteristics. Therefore, the appropriate polysiloxane block ratio should also be selected according to the application scenario of the material.

[0144] According to the analysis of Tables 1 to 3, when the proportion of polysiloxane blocks in SS-co-PC materials is 5-10%, the comprehensive performance can achieve the best balance. Compared with the existing high-impact transparent-flame-retardant PC technology, the present invention, through a chemical copolymerization scheme, relies on the toughening, anti-drip and smoke suppression and toxicity reduction effects of functionalized polysiloxane, combined with the specific and efficient flame retardant advantages of sulfonates on PC (its content in SS-co-PC materials is as low as one ten-thousandth of an order of magnitude), and cleverly gives the copolymerized PC products the goals of high transparency, impact resistance, low smoke and flame retardancy that are difficult to achieve at the same time. At the same time, compared with the blended modified composite materials, the SS-co-PC material of the present invention also has better consistency and stability, and higher added value.

[0145] Finally, it should be understood that the embodiments of the application disclosed herein are explanations of the principles of the embodiments of the present application. Other modified embodiments are also within the scope of the present application. Therefore, the embodiments disclosed in the present application are merely examples and not limitations. Those skilled in the art can adopt alternative configurations according to the embodiments in the present application to realize the application in the present application. Therefore, the embodiments of the present application are not limited to those embodiments that have been accurately described in the application.

Claims

1. A hydroxy-terminated siloxane oligomer, characterized in that: The structural formula is: Wherein, m+n≥15, m1≥0, m2≥0; R1 and R2 respectively include at least one of -H, -CH3 or -C2H5, and R3 includes at least one of -H or -CH3 or -C2H5 or -CN.

2. A method for preparing the hydroxy-terminated siloxane oligomer according to claim 1, characterized in that: include: causing octasubstituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane to undergo polymerization reaction to form a polysiloxane oligomer; The amino group in the polysiloxane oligomer and the aldehyde group in the aromatic aldehyde undergo an aldehyde-amine condensation reaction to generate the terminal hydroxyl siloxane oligomer.

3. The method for preparing the hydroxy-terminated siloxane oligomer according to claim 2, characterized in that: The polymerization reaction is carried out under the action of a first catalyst, which includes at least one of (Ph3P)4Pd, (Ph3P)2PdCl2, [RhCl(CO)2]2, (Ph3P)2NiCl2, chloroplatinic acid or tetramethylammonium hydroxide pentahydrate, and the molar percentage of the first catalyst accounts for 0.01 to 4.5% of all reactants in the polymerization reaction.

4. The method for preparing the hydroxy-terminated siloxane oligomer according to claim 3, characterized in that: The polymerization reaction is carried out in a first solvent, which includes any two of water, ethanol, N-N'-dimethylformamide, acetone, chloroform and dimethyl sulfoxide, and the volume ratio of the two solvents in the first solvent is 3:1 to 1:

4.

5. The method for preparing the hydroxy-terminated siloxane oligomer according to claim 4, characterized in that: The method of polymerizing octasubstituted cyclotetrasiloxane and 3-aminopropylmethyldiethoxysilane to form a polysiloxane oligomer comprises: subjecting octasubstituted cyclotetrasiloxane, 3-aminopropylmethyldiethoxysilane, the first catalyst and the first solvent to a reflux reaction at a temperature of 65 to 90° C. for a first time, wherein the first time is 15 to 60 minutes; stirring the system in an oil bath at 80 to 150° C. until the system becomes viscous, removing the first catalyst, and performing a rotary evaporation process to remove low-boiling impurities to obtain the polysiloxane oligomer.

6. The method for preparing the hydroxy-terminated siloxane oligomer according to claim 2, characterized in that: The aromatic aldehyde is an aromatic aldehyde in which the aldehyde group and R3 are substituted at the para position.

7. A copolymer PC, characterized in that: The structural formula is: Among them, m+n≥15, m1≥0, m2≥0; R1 and R2 respectively include at least one of -H, -CH3 or -C2H5, and R3 includes at least one of -H or -CH3 or -C2H5 or -CN; x+y+z≥70, x≥0, y≥0, z=m+n; 1%≤z / (x+y+z)≤65%.

8. The copolymerized PC as claimed in claim 7, characterized in that Said The mass percentage content of the group is 0.5 to 48%, The mass percentage content of the group is 0.2 to 3‰.

9. The method for preparing copolymerized PC as claimed in claim 7 or 8, characterized in that: include: Bisphenol A, diphenyl carbonate, disodium 3,6-dihydroxy-2,7-naphthalene disulfonate and terminal hydroxyl siloxane oligomer are used as raw materials to carry out melt polycondensation reaction to obtain the copolymer PC.

10. The method for preparing copolymerized PC according to claim 9, characterized in that: The melt polycondensation reaction includes a first reaction stage and a second reaction stage, wherein the first reaction stage is carried out at a temperature of 140 to 270° C. for 1 to 6 hours to complete the ester exchange process; the second reaction stage is carried out at a temperature of 250 to 320° C. for 0.5 to 1 hour to complete the condensation polymerization and functional block copolymerization processes.

11. The method for preparing copolymerized PC according to claim 9, characterized in that: The melt polycondensation reaction is carried out under the action of a second catalyst, and the second catalyst includes at least one of tri-n-butylamine, tetrabutylammonium hydroxide and tetrabutylammonium chloride.

12. The method for preparing copolymerized PC according to claim 9, characterized in that: The molar ratio of bisphenol A, diphenyl carbonate, terminal hydroxyl siloxane oligomer and disodium 3,6-dihydroxy-2,7-naphthalene disulfonate is: 1:2:(0.02-0.99):(0.00005-0.005).

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