Chemical-resistant polycarbonate modified plastic and preparation method thereof

Abstract

The invention discloses chemical-resistant polycarbonate modified plastic and a preparation method thereof, and relates to the technical field of materials for non-metal additive materials. The preparation method comprises the following steps: weighing modified polycarbonate, polyphenylene sulfide, a flame-retardant light curing agent, an antioxidant, an ultraviolet light absorber, a solvent-resistant diluent, a nano reinforcing filler, boron nitride nanosheets, short carbon fibers, nano barium sulfate, a chemical-resistant toughening agent and a flatting agent in parts by weight, distributing and premixing to obtain a premixed solution, grinding and dispersing by three rollers to obtain a premix, and granulating to obtain the flame-retardant polycarbonate composite material. The preparation method comprises the following steps: carrying out vacuum defoaming to obtain a crude resin material, carrying out DLP printing (3D printing) molding, and carrying out warm water debonding and stepped curing treatment to obtain the chemical-resistant polycarbonate modified plastic with excellent chemical resistance, mechanical properties, thermal properties and flame retardancy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of non-metallic additive materials, in particular to a chemical-resistant polycarbonate modified plastic and a preparation method thereof. BACKGROUND

[0002] Polycarbonate materials are widely used in engineering fields due to their excellent mechanical properties and transparency, but they are prone to stress cracking, swelling deformation and other problems in strong solvent, high temperature and stress coupling environments. Traditional modification methods such as blending rubber toughening improve impact resistance, but sacrifice chemical resistance; while adding inorganic fillers enhances rigidity, but often leads to deterioration of processing fluidity. Especially for additive manufacturing scenarios, existing photocurable resins generally have poor solvent resistance, and it is difficult to balance flame retardance and toughness, and other defects, which cannot meet the long-term service requirements of complex structure functional parts in extreme environments in chemical equipment, aerospace and other fields. Therefore, an innovative material system with multiple protection mechanisms and additive manufacturing adaptability is urgently needed. SUMMARY

[0003] The purpose of the present application is to provide a chemical-resistant polycarbonate modified plastic and a preparation method thereof to solve the problems raised in the background art.

[0004] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0005] A chemical-resistant polycarbonate modified plastic comprises the following raw materials by weight:

[0006] Modified polycarbonate 60-70 parts;

[0007] Polyphenylene sulfide 20-25 parts;

[0008] Solvent-resistant diluent 20-25 parts;

[0009] Nano-enhanced filler 8-12 parts;

[0010] Boron nitride nanosheet 2-4 parts;

[0011] Short carbon fiber 4-6 parts;

[0012] Nano-barium sulfate 1-2 parts;

[0013] Flame-retardant photocuring agent 4-6 parts;

[0014] Chemical-resistant toughening agent 10-15 parts;

[0015] Antioxidant 0.5-1 part;

[0016] Leveling agent 0.5-1 part;

[0017] Ultraviolet absorber 0.3-0.5 parts.

[0018] Further, the preparation steps of the modified polycarbonate are as follows:

[0019] The bisphenol A polycarbonate particles are vacuum dried at 100-120℃ for 4h, and the hydroxyl-terminated polydimethylsiloxane is added into the internal mixer, and pre-mixed at 175-185℃ for 8-12min, and then 4,4-diphenyl methane diisocyanate and dibutyltin dilaurate are added, and reacted at 175-185℃ under nitrogen protection for 12-18min, and then reacted at 190-210℃ under nitrogen protection for another 6-10min, and the torque peak value of the internal mixer is ensured to be ≥35N·m, and the torque fluctuation is ≤±2%, and the obtained melt is granulated by a twin-screw extruder to obtain the modified polycarbonate;

[0020] The molecular weight of the hydroxyl-terminated polydimethylsiloxane is 2000;

[0021] The mass ratio of the bisphenol A polycarbonate, the hydroxyl-terminated polydimethylsiloxane, the 4,4-diphenyl methane diisocyanate and the dibutyltin dilaurate is (55-65):(14-16):(4-6):0.05.

[0022] It should be noted that the polydimethylsiloxane is introduced into the polycarbonate molecular chain by block copolymerization strategy, and a protective barrier is formed by using the hydrophobicity and flexibility of the siloxane segment: the hydrophobic group shields the erosion of polar solvents, and the flexible segment reduces the internal stress, thereby inhibiting the hydrolysis of the ester bond of the polycarbonate and stress cracking. The modified polycarbonate forms a bicontinuous phase with the polyphenylene sulfide, the high solvent resistance phase of the polyphenylene sulfide blocks the penetration of chemical media, and the siloxane segment enhances the compatibility of the phase interface, thereby synergistically improving the overall chemical fatigue resistance.

[0023] Further, the preparation steps of the solvent-resistant diluent are as follows:

[0024] Trimethylolpropane triacrylate is mixed with tridecafluorooctyltriethoxysilane, and then titanium tetraisopropylate and 2,6-di-tert-butyl-p-cresol polymerization inhibitor are added, and the nitrogen is replaced for three times, and then the mixture is reacted at 75-85℃ for 2-3h, and then the temperature is increased to 95-105℃ and the pressure is reduced to-0.09MPa for 2-3h, and then the product is filtered through a 0.45μm filter membrane to obtain the solvent-resistant diluent;

[0025] The mass ratio of the trimethylolpropane triacrylate, the tridecafluorooctyltriethoxysilane, the titanium tetraisopropylate and the 2,6-di-tert-butyl-p-cresol polymerization inhibitor is (68-72):(28.8-31.2):0.3:(0.09-0.11).

[0026] It should be noted that based on the ester exchange reaction, the perfluoroalkyl group is grafted to the acrylate skeleton, and the fluorine-containing segment migrates to the surface during curing to form a low-energy enrichment layer, which significantly reduces the wetting and penetration tendency of the solvent at the material interface. Solvent-resistant diluents participate in the construction of the polymer network during photocuring, and the fluorine-containing segments of the modified polycarbonate and the siloxane segments produce a synergistic reduction in surface energy, which collectively enhances the material's ability to repel polar solvents while maintaining low viscosity to meet the needs of additive manufacturing.

[0027] Further, the preparation steps of the nano-reinforced filler are as follows:

[0028] The hollow titanium dioxide microspheres are dispersed in an ethanol solution, gamma-methacryloxypropyltrimethoxysilane is added, the pH is adjusted to 4.5-5, hydrolysis is carried out at 75-85℃ for 1-2h, multi-walled carbon nanotubes are added and ultrasonic dispersion is carried out for 20-40min, reaction is carried out at 100-105℃ for 3-4h, centrifugation and washing are carried out, and the nano-reinforced filler is obtained;

[0029] The mass fraction of ethanol in the ethanol solution is 70-90%;

[0030] The mass ratio of the hollow titanium dioxide microspheres, gamma-methacryloxypropyltrimethoxysilane, and multi-walled carbon nanotubes is (35-45):(8-12):(8-12).

[0031] It should be noted that by constructing a reactive interface on the surface of the titanium dioxide microspheres with a silane coupling agent, and by means of hydroxyl condensation and van der Waals force, the carbon nanotubes are physically anchored, forming a core-shell heterostructure with rigid microspheres and ductile nanotubes. The nano-reinforced filler realizes multi-level toughening in the chemical-resistant polycarbonate modified plastic by resisting compression deformation through microspheres and bridging dispersed tensile stress through carbon nanotubes, its formed three-dimensional interpenetrating network increases the tortuosity of solvent diffusion, and the surface acrylate groups chemically bond with the resin matrix to eliminate interface defects and block the medium penetration channel.

[0032] Further, the preparation steps of the flame-retardant photocuring agent are as follows:

[0033] The preparation steps of the flame-retardant photocuring agent are as follows:

[0034] 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 2-hydroxy-4-(methacryloyloxy) benzophenone are dissolved in toluene, dicumyl peroxide is added, refluxed at 100-120℃ for 4-8h, rotary evaporation, drying, and the flame-retardant photocuring agent is obtained;

[0035] The use amount ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, toluene and dicumyl peroxide is 50g:50g:300mL:0.5g.

[0036] It should be noted that the P-H bond of the phosphorus flame-retardant unit (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide) is covalently bonded to the carbon-carbon double bond of the ultraviolet light absorbing group (2-hydroxy-4-(methacryloyloxy)benzophenone) through a free radical addition reaction to form a multifunctional integrated compound. The phosphorus element in the flame-retardant photocuring agent releases free radicals at high temperatures to capture active oxygen in combustion chain reactions, plays a gas phase flame-retardant role, and inhibits combustion; at the same time, the methacryloyloxy group participates in the construction of the crosslinking network, anchors the phosphorus flame-retardant unit, and the residual phenolic hydroxyl group forms hydrogen bonds with the polar groups of the resin to cooperatively reduce the interfacial energy barrier, block the solvent permeation microchannels, and both inhibit solvent permeation along the interface and achieve the synergistic reinforcement of flame retardancy and chemical resistance under the premise of ensuring photocuring efficiency.

[0037] Further, the chemical-resistant toughening agent is a fluorinated modified polyurethane acrylate.

[0038] Further, the boron nitride nanosheet needs to be surface modified by a KH560 silane coupling agent.

[0039] Further, the short carbon fiber needs to be surface treated by acid immersion and surface modified by polydopamine.

[0040] Further, the antioxidant is one or several of a phosphite type antioxidant and a hindered phenol type antioxidant.

[0041] Further, the leveling agent is a polyether modified fluorine-containing polydimethylsiloxane type leveling agent.

[0042] Further, the anti-ultraviolet aging agent is a benzotriazole type ultraviolet absorber.

[0043] A preparation step of a chemical-resistant polycarbonate modified plastic is as follows:

[0044] S1, 60-70 parts by weight of modified polycarbonate, 20-25 parts by weight of polyphenylene sulfide, 4-6 parts by weight of flame retardant photocuring agent, 0.5-1 parts by weight of antioxidant and 0.3-0.5 parts by weight of ultraviolet absorber are weighed and added into a planetary mixer, stirred at 150-250 r / min for 10-15 min at 25 DEG C; 20-25 parts by weight of solvent-resistant diluent is weighed and added, stirred at 150-250 r / min for 1-3 min, 8-12 parts by weight of nano-enhanced filler, 2-4 parts by weight of boron nitride nanosheet, 4-6 parts by weight of short carbon fiber and 1-2 parts by weight of nano-barium sulfate are added, and stirred at 150-250 r / min for 1-3 min; the speed is reduced to 40-60 r / min, 10-15 parts by weight of chemical toughening agent and 0.5-1 parts by weight of leveling agent are weighed and added, and stirred for 3-5 min to obtain a premix;

[0045] S2, the premix is transferred to a three-roll mill, the roll spacing is 50 mu m, the roll speed ratio is 1:3:9, and the circulation is 3 times to obtain a premix; the premix is placed in a vacuum defoaming machine, the vacuum degree is-0.095 MPa, 25 DEG C, and the defoaming time is 15 min to obtain a crude resin material;

[0046] Further, the bubble residue in the crude resin material in step S2 is less than 0.1%;

[0047] S3, the crude resin material is poured into a resin tank, a DLP photocuring printer is turned on, a 405 nm light source is selected, the light intensity is set to 12-16 mW / cm2, a designed master model file is imported, the layer thickness is set to 1-10 mm, after printing, the obtained crude master particle is soaked in 30-35 DEG C warm water for 20-40 min, taken out and placed at 25 DEG C for 20-40 min, placed in a 60 DEG C oven and dried for 30-60 min, the dried crude master particle is placed in an ultraviolet curing box, set to 365 nm wavelength and 8-12 mW / cm2 intensity, irradiated for 15-20 min, placed in a 45-50 DEG C oven for 40-80 min, the oven is heated to 80 DEG C and placed for 90-150 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic;

[0048] Further, in step S3, an infrared thermal imager is aimed at the printing area to ensure that the temperature is lower than 60 DEG C, if the temperature is too high, the printing is paused and the light intensity is reduced or the interlayer cooling time is increased.

[0049] Compared with the prior art, the present application has the following beneficial effects:

[0050] The siloxane block of the modified polycarbonate forms a hydrophobic barrier with the solvent-resistant diluent, the core-shell nano-reinforced filler constructs a physical barrier network, and cooperatively resists strong solvent erosion and environmental stress cracking; the light and heat dual-curing process ensures molding, simultaneously excites chemical bonding of the flame-retardant light-curing agent and the matrix, and endows the chemical-resistant polycarbonate modified plastic with persistent flame retardance; the short-cut carbon fiber and boron nitride nanosheet synergistically improve the mechanical strength and thermal stability after surface modification. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0052] Table 1

[0053] Material Source Bisphenol A polycarbonate Aladdin P301659 Hollow titanium dioxide microspheres Xi'an Ruiyi Biological Technology 124531 Multi-walled carbon nanotubes Nanjing Xianfeng Nanometer Material Technology XFM31 Nano hexagonal boron nitride sheet Beijing Naisi Biochemical Technology R095879 Carbon fiber Nantong Wayon New Material T300 / 400 / 700 Nano barium sulfate Foshan Bozhen Chemical Industry BZ-3000 Antioxidant BASF Antioxidant 1010 Leveling agent Hubei Xinyu Hong Biological Medicine Technology S112298605 Ultraviolet absorber BASF Tinuvin 329

[0054] Preparation Example 1

[0055] The preparation steps of the modified polycarbonate are as follows:

[0056] The bisphenol A polycarbonate particles are vacuum dried at 110 DEG C for 4 h, and are added to a mixing mill together with the hydroxyl-terminated polydimethylsiloxane. The mixture is pre-mixed at 180 DEG C for 10 min, and then 4,4-diphenyl methane diisocyanate and dibutyl tin dilaurate are added. After reaction at 180 DEG C under nitrogen protection for 15 min, the reaction is continued at 200 DEG C under nitrogen protection for another 8 min. The torque peak value of the mixing mill is ensured to be greater than or equal to 35 N·m, and the torque fluctuation is ensured to be less than or equal to ± 2% during the whole process. The obtained melt is granulated by a twin-screw extruder, with the feeding section at 215 DEG C, the melting section at 255 DEG C, the mixing section at 275 DEG C, the exhaust section at 270 DEG C, the homogenizing section at 250 DEG C, and the die at 265 DEG C, to obtain the modified polycarbonate.

[0057] The molecular weight of the hydroxyl-terminated polydimethylsiloxane is 2000.

[0058] The mass ratio of the bisphenol A polycarbonate, the hydroxyl-terminated polydimethylsiloxane, the 4,4-diphenyl methane diisocyanate and the dibutyl tin dilaurate is 60:15:5:0.05.

[0059] Preparation Example 2

[0060] The preparation steps of the solvent-resistant diluent are as follows:

[0061] Trimethylolpropane triacrylate is mixed with tridecafluorooctyltriethoxysilane, tetraisopropyl titanate and 2,6-di-tert-butyl-p-cresol polymerization inhibitor, nitrogen is replaced three times, reaction is carried out at 80℃ for 2h, the temperature is raised to 100℃, the vacuum system is opened, and the step-by-step decompression method is adopted: the vacuum degree is slowly adjusted to-0.05MPa first, maintained for 30min, after the reaction system is stable and no violent bubbles are generated, the vacuum degree is slowly increased to-0.07MPa, maintained for 1h, and then the vacuum degree is slowly increased to-0.08MPa, maintained for 90min, the product is filtered through a 0.45μm filter membrane to obtain the solvent-resistant diluent;

[0062] During the adjustment of the vacuum degree, attention should be paid to the foaming of the system, if there is a tendency of violent boiling, the vacuum should be paused or the vacuum degree should be slightly adjusted to be lower, and then the pressure should be slowly increased after the system is stable;

[0063] The mass ratio of the trimethylolpropane triacrylate, tridecafluorooctyltriethoxysilane, tetraisopropyl titanate and 2,6-di-tert-butyl-p-cresol polymerization inhibitor is 70:30:0.3:0.1.

[0064] Preparation Example 3

[0065] The preparation steps of the nano-enhanced filler are as follows:

[0066] Hollow titanium dioxide microspheres are dispersed in an ethanol solution, γ-methacryloyloxypropyltrimethoxysilane is added, the pH is adjusted to 5, hydrolysis is carried out at 80℃ for 2h, multi-walled carbon nanotubes are added and ultrasonic dispersion is carried out for 30min, reaction is carried out at 100℃ for 3h, and centrifugation and washing are carried out to obtain the nano-enhanced filler;

[0067] The mass fraction of ethanol in the ethanol solution is 80%;

[0068] The mass ratio of the hollow titanium dioxide microspheres, the ethanol solution, the γ-methacryloyloxypropyltrimethoxysilane and the multi-walled carbon nanotubes is 40:800:10:10.

[0069] Preparation Example 4

[0070] The preparation steps of the flame-retardant photocuring agent are as follows:

[0071] 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is dissolved in toluene with 2-hydroxy-4-(methacryloyloxy)benzophenone, dicumyl peroxide is added, reflux is carried out at 110℃ for 6h, rotary evaporation is carried out, drying is carried out to obtain the flame-retardant photocuring agent;

[0072] The use amount ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, toluene and dicumyl peroxide is 50g:50g:300mL:0.5g.

[0073] Preparation Example 5

[0074] The preparation steps of the chemical-resistant toughening agent are as follows:

[0075] The polyurethane acrylate is dehydrated at 80℃ under reduced pressure for 1h, full-fluorodecyl triethoxysilane and glacial acetic acid are added, and reaction is carried out at 90℃ for 4h to obtain the chemical-resistant toughening agent.

[0076] The polyurethane acrylate is purchased from Jining Huakai Resin Co., Ltd., and the product code is AL669692508244.

[0077] The use amount ratio of the polyurethane acrylate, full-fluorodecyl triethoxysilane and glacial acetic acid is 100g:20g:0.1mL.

[0078] Preparation Example 6

[0079] The preparation steps of the boron nitride nanosheet are as follows:

[0080] The nanohexagonal boron nitride sheet is dispersed in an ethanol solution, KH560 silane coupling agent is added, the pH is adjusted to 5, and reaction is carried out at 80℃ for 4h, centrifugal washing and drying at 120℃ for 2h to obtain the boron nitride nanosheet.

[0081] The mass fraction of ethanol in the ethanol solution is 80%.

[0082] The use amount ratio of the nanohexagonal boron nitride sheet, ethanol solution and KH560 silane coupling agent is 10g:200mL:1.5g.

[0083] Preparation Example 7

[0084] The preparation steps of the short carbon fiber are as follows:

[0085] The carbon fiber is immersed in concentrated nitric acid with a mass fraction of 65%, treated at 60℃ for 30min, washed with water to neutral, dried at 105℃, coated with a dopamine solution, and naturally dried for 24h to form a polydopamine coating, thereby obtaining the short carbon fiber.

[0086] The dopamine solution is a Tris buffer solution with a dopamine concentration of 2g / L and a pH of 8.5.

[0087] The use amount ratio of the carbon fiber, concentrated nitric acid and dopamine solution is 10g:100mL:100mL.

[0088] Example 1

[0089] A preparation procedure of a chemical-resistant polycarbonate modified plastic is as follows:

[0090] S1, 65 parts of modified polycarbonate, 22.5 parts of polyphenylene sulfide, 5 parts of flame-retardant photocuring agent, 0.8 parts of antioxidant and 0.4 parts of ultraviolet absorber were weighed by weight parts, added into a planetary mixer, stirred at 25°C at a speed of 200 r / min for 12 min; 22.5 parts of solvent-resistant diluent were weighed by weight parts and added, stirred at a speed of 200 r / min for 2 min, 10 parts of nano-enhanced filler, 3 parts of boron nitride nanosheet, 5 parts of short carbon fiber and 1.5 parts of nano-barium sulfate were added, stirred at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 12.5 parts of chemical-resistant toughening agent and 0.8 parts of leveling agent were weighed by weight parts and added, stirred for 4 min to obtain a premix;

[0091] The polyphenylene sulfide is purchased from Merck Chemical, item number 182354.

[0092] S2, the premix was transferred to a three-roll mill, the roll spacing was 50 μm, the roll speed ratio was 1:3:9, and the circulation was 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine, the vacuum degree was-0.095 MPa, 25°C, and defoaming was carried out for 15 min to obtain a crude resin material;

[0093] S3, the crude resin material was poured into a resin tank, a DLP photocuring printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed masterbatch model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after the printing was completed, the obtained crude masterbatch was soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, placed in a 60°C oven for drying for 45 min, the dried crude masterbatch was placed in an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0094] Some raw materials involved in the embodiment are prepared by the substances prepared in Preparation Examples 1-7, and the other embodiments are the same.

[0095] Example 2

[0096] A preparation procedure of a chemical-resistant polycarbonate modified plastic is as follows:

[0097] S1, 60 parts of modified polycarbonate, 20 parts of polyphenylene sulfide, 4 parts of flame-retardant photocuring agent, 0.5 parts of antioxidant and 0.3 parts of ultraviolet absorber were weighed by weight parts, added into a planetary stirrer, stirred at 25°C at a speed of 200 r / min for 10 min; 20 parts of solvent-resistant diluent were weighed by weight parts and added, stirred at a speed of 200 r / min for 2 min, 8 parts of nano-enhanced filler, 2 parts of boron nitride nanosheet, 4 parts of short carbon fiber and 1 part of nano-barium sulfate were added, stirred at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 10 parts of chemical-resistant toughening agent and 0.5 parts of leveling agent were weighed by weight parts and added, stirred for 4 min to obtain a premix;

[0098] S2, the premix was transferred to a three-roll grinder, the roll spacing was 50 μm, the roll speed ratio was 1:3:9, and the circulation was 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine, the vacuum degree was-0.095 MPa, 25°C, and defoaming was carried out for 15 min to obtain a crude resin material; the bubble residue in the crude resin material was less than 0.1%;

[0099] S3, the crude resin material was poured into a resin tank, a DLP photocuring printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed masterbatch model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after the printing was completed, the obtained crude masterbatch was soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, placed in a 60°C oven for drying for 45 min, the dried crude masterbatch was placed in an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0100] Example 3

[0101] A preparation step of a chemical-resistant polycarbonate modified plastic is as follows:

[0102] S1. Weigh 70 parts of modified polycarbonate, 25 parts of polyphenylene sulfide, 6 parts of flame retardant light curing agent, 1 part of antioxidant and 0.5 part of ultraviolet absorber by weight, add them into a planetary mixer, and stir at a speed of 200 r / min for 15 minutes at 25°C; weigh and add 25 parts of solvent-resistant diluent by weight, stir at a speed of 200 r / min for 3 minutes, add 12 parts of nano-reinforced filler, 4 parts of boron nitride nanosheets, 6 parts of chopped carbon fibers and 2 parts of nano-barium sulfate, and stir at a speed of 200 r / min for 3 minutes; reduce the speed to 50 r / min, weigh and add 15 parts of chemical-resistant toughening agent and 1 part of leveling agent by weight, and stir for 5 minutes to obtain a premixed solution;

[0103] S2. The premixed liquid was transferred to a three-roll mill with a roller spacing of 50 μm and a roller speed ratio of 1:3:9, and the process was repeated three times to obtain a premixed material. The premixed material was placed in a vacuum degassing machine with a vacuum degree of -0.095 MPa and a temperature of 25° C. for 15 minutes to obtain a crude resin material. The crude resin material contained less than 0.1% residual bubbles.

[0104] S3. Pour the crude resin material into the resin tank, turn on the DLP light-curing printer, select a 405nm light source, set the light intensity to 15mW / cm², import the designed masterbatch model file, set the layer thickness to 5mm, aim the infrared thermal imager at the printing area, and ensure that the temperature is below 60℃. If the temperature exceeds 60℃, pause printing and reduce the light intensity or increase the inter-layer cooling time. After printing, soak the obtained crude masterbatch in 35℃ warm water for 30min, take it out and let it stand at 25℃ for 30min, and put it in a 60℃ oven to dry for 45min. Put the dried crude masterbatch into a UV curing box, set the wavelength to 365nm and the intensity to 10mW / cm², irradiate for 18min, let it stand in a 50℃ oven for 60min, heat the oven to 80℃ and let it stand for 120min, and naturally cool to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0105] Comparative Example 1

[0106] The preparation steps of a chemical-resistant polycarbonate modified plastic are as follows:

[0107] S1, 65 parts by weight of bisphenol A polycarbonate, 22.5 parts by weight of polyphenylene sulfide, 5 parts by weight of flame-retardant photocuring agent, 0.8 parts by weight of antioxidant and 0.4 parts by weight of ultraviolet absorber were weighed and added to a planetary mixer, stirred at 25°C at a speed of 200 r / min for 12 min; 22.5 parts by weight of solvent-resistant diluent was weighed and added, stirred at a speed of 200 r / min for 2 min, 10 parts by weight of nano-enhanced filler, 3 parts by weight of boron nitride nanosheet, 5 parts by weight of short carbon fiber and 1.5 parts by weight of nano-barium sulfate were added, and stirred at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 12.5 parts by weight of chemical-resistant toughening agent and 0.8 parts by weight of leveling agent were weighed and added, and stirred for 4 min to obtain a premix;

[0108] S2, the premix was transferred to a three-roll mill with a roll spacing of 50 μm, a roll speed ratio of 1:3:9, and a cycle of 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine with a vacuum degree of -0.095 MPa at 25°C and defoamed for 15 min to obtain a crude resin material; the bubble residue in the crude resin material was less than 0.1%;

[0109] S3, the crude resin material was poured into a resin tank, a DLP photocuring printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed master model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after printing, the obtained crude master granules were soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, placed in a 60°C oven for drying for 45 min, the dried crude master granules were placed in an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain the chemical-resistant polycarbonate modified plastic.

[0110] The difference between the present comparative example and Example 1 is that the modified polycarbonate is not added, but an unmodified bisphenol A polycarbonate is added instead.

[0111] Comparative Example 2

[0112] A preparation step of a chemical-resistant polycarbonate modified plastic is as follows:

[0113] S1, 65 parts of modified polycarbonate, 22.5 parts of polyphenylene sulfide, 5 parts of flame-retardant photocuring agent, 0.8 parts of antioxidant and 0.4 parts of ultraviolet absorber were weighed by weight parts, added into a planetary mixer, stirred at 25°C at a speed of 200 r / min for 12 min; 22.5 parts of trimethylolpropane triacrylate were weighed and added, stirred at a speed of 200 r / min for 2 min, 10 parts of nano-enhanced filler, 3 parts of boron nitride nanosheet, 5 parts of short carbon fiber and 1.5 parts of nano-barium sulfate were added, stirred at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 12.5 parts of chemical-resistant toughening agent and 0.8 parts of leveling agent were weighed and added, stirred for 4 min to obtain a premix;

[0114] S2, the premix was transferred to a three-roll mill, the roll spacing was 50 μm, the roll speed ratio was 1:3:9, and the circulation was 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine, the vacuum degree was-0.095 MPa, 25°C, and defoaming was carried out for 15 min to obtain a crude resin material; the bubble residue in the crude resin material was less than 0.1%;

[0115] S3, the crude resin material was poured into a resin tank, a DLP photocuring printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed master model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after the printing was completed, the obtained crude master granules were soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, put into a 60°C oven and dried for 45 min, the dried crude master granules were put into an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0116] The difference between the present comparative example and example 1 is that the solvent-resistant diluent is not added, but trimethylolpropane triacrylate is added as a diluent instead.

[0117] Comparative Example 3

[0118] A preparation step of a chemical-resistant polycarbonate modified plastic is as follows:

[0119] S1, 65 parts by weight of modified polycarbonate, 22.5 parts by weight of polyphenylene sulfide, 5 parts by weight of flame-retardant photocuring agent, 0.8 parts by weight of antioxidant and 0.4 parts by weight of ultraviolet absorber were weighed and added to a planetary mixer, stirred at 25°C at a speed of 200 r / min for 12 min; 22.5 parts by weight of solvent-resistant diluent was weighed and added, stirred at a speed of 200 r / min for 2 min, 10 parts of hollow titanium dioxide microspheres, 3 parts of boron nitride nanosheet, 5 parts of short carbon fiber and 1.5 parts of nano-barium sulfate were added, stirred at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 12.5 parts by weight of chemical-resistant toughening agent and 0.8 parts by weight of leveling agent were weighed and added, stirred for 4 min to obtain a premix;

[0120] S2, the premix was transferred to a three-roll mill, the roll spacing was 50 μm, the roll speed ratio was 1:3:9, and the circulation was 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine, the vacuum degree was-0.095 MPa, 25°C, and defoaming was carried out for 15 min to obtain a crude resin material; the bubble residue in the crude resin material was less than 0.1%;

[0121] S3, the crude resin material was poured into a resin tank, a DLP photocuring printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed master model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after printing, the obtained crude master granules were soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, placed in a 60°C oven for drying for 45 min, the dried crude master granules were placed in an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0122] The difference between the present comparative example and example 1 is that no nano-enhanced filler is added, but an unmodified hollow titanium dioxide microsphere is added instead.

[0123] Comparative Example 4

[0124] A preparation step of a chemical-resistant polycarbonate modified plastic is as follows:

[0125] S1, 65 parts of modified polycarbonate, 22.5 parts of polyphenylene sulfide, 5 parts of 2-hydroxy-4-(methacryloyloxy) benzophenone, 0.8 parts of antioxidant and 0.4 parts of ultraviolet absorber were weighed and added into a planetary mixer, stirred at 25°C at a speed of 200 r / min for 12 min; 22.5 parts of solvent-resistant diluent were weighed and added at a speed of 200 r / min for 2 min, 10 parts of nano-enhanced filler, 3 parts of boron nitride nanosheet, 5 parts of short carbon fiber and 1.5 parts of nano-barium sulfate were added at a speed of 200 r / min for 2 min; the speed was reduced to 50 r / min, 12.5 parts of chemical toughening agent and 0.8 parts of leveling agent were weighed and added, stirred for 4 min to obtain a premix;

[0126] S2, the premix was transferred to a three-roll mill with a roll spacing of 50 μm, a roll speed ratio of 1:3:9 and a cycle of 3 times to obtain a premix; the premix was placed in a vacuum defoaming machine with a vacuum degree of -0.095 MPa at 25°C and defoamed for 15 min to obtain a crude resin material; the bubble residue in the crude resin material was less than 0.1%;

[0127] S3, the crude resin material was poured into a resin tank, a DLP light curing printer was turned on, a 405 nm light source was selected, the light intensity was set to 15 mW / cm², a designed masterbatch model file was imported, the layer thickness was set to 5 mm, an infrared thermal imager was aimed at the printing area to ensure that the temperature was lower than 60°C, if the temperature was too high, the printing was paused and the light intensity was reduced or the interlayer cooling time was increased, after the printing was completed, the obtained crude masterbatch was soaked in 35°C warm water for 30 min, taken out and placed at 25°C for 30 min, placed in a 60°C oven for drying for 45 min, the dried crude masterbatch was placed in an ultraviolet curing box, set to 365 nm wavelength and 10 mW / cm² intensity, irradiated for 18 min, placed in a 50°C oven for 60 min, the oven was heated to 80°C and placed for 120 min, and naturally cooled to room temperature to obtain a chemical-resistant polycarbonate modified plastic.

[0128] The difference between the present comparative example and example 1 is that the flame-retardant light-curing agent is not added, but 2-hydroxy-4-(methacryloyloxy) benzophenone is added instead.

[0129] Test:

[0130] I. Chemical corrosion resistance

[0131] Ethyl acetate immersion for 72 h (mass loss Δm): “ASTM D543-21 Standard Practice for Evaluating the Resistance of Plastics to Chemical Reagents”

[0132] Chemical corrosion tensile strength retention rate: GB / T 1040.1-2018 Plastics - Determination of tensile properties - Part 1 : general principles, formula: chemical corrosion tensile strength retention rate = tensile strength after corrosion / original tensile strength x 100%.

[0133] The test results are shown in Table 2.

[0134] Table 2: Test results

[0135] Sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Δm 0.04 0.05 0.02 0.62 0.38 0.29 0.11 Tensile strength retention rate after chemical corrosion (%) 91.4 90.2 90.6 63.7 75.5 79.3 85.9

[0136] II. Mechanical properties

[0137] Tensile strength was tested according to GB / T 1040.1-2018 Plastics - Determination of tensile properties - Part 1 : general principles.

[0138] Flexural strength was tested according to GB / T 9341-2008 Plastics - Determination of flexural properties.

[0139] Impact strength was tested according to GB / T 1843-2008 Plastics - Determination of Izod Charpy impact strength.

[0140] The test results are shown in Table 3.

[0141] Table 3: Test results

[0142] Sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Tensile strength (MPa) 68.7 66.2 70.5 48.3 55.1 51.6 65.8 Flexural strength (MPa) 105.5 99.3 103.7 72.6 85.4 76.9 98.1 Impact strength (kJ / m 2 ) 84.7 81.5 88.6 52.4 68.3 60.7 80.2

[0143] III. Thermal properties

[0144] Heat distortion temperature was tested according to ASTM D648 Standard Test Method for Heat Distortion Temperatures of Plastics.

[0145] The test results are shown in Table 4.

[0146] Table 4: Test results

[0147] Sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Heat distortion temperature (℃) 163 158 161 138 145 142 156

[0148] IV. Flame retardant properties

[0149] Vertical burning rating (UL 94): GB / T 2408-2021 Plastics - Determination of the burning behavior in an inclined plane and in a vertical plane

[0150] Heat release capacity (HRC): ISO 5660-1:2015 Fire behaviour of materials - Part 1 : Heat release rate (cone calorimeter method)

[0151] Peak Heat Release Rate (‌PHRR): ISO 5660-1:2015 Reaction to fire tests — Heat release, smoke production and mass loss rates — Part 1: Heat release rate (Cone calorimeter method)

[0152] Total heat release (THR): ISO 5660-1:2015 Reaction to fire tests — Heat release, smoke production and mass loss rates — Part 1: Heat release rate (Cone calorimeter method)

[0153] Residual carbon rate (W): GB / T 33047.1-2016 Plastic polymers thermogravimetric method (TG) Part 1: General principles

[0154] Limiting Oxygen Index (LOI): GB / T 2406.2-2009 Plastics - Determination of Combustion Behavior by Oxygen Index Method - Part 2: Room Temperature Test

[0155] The test results are shown in Table 5.

[0156] Table 5: Test results

[0157] Sample Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 UL 94 V0 V0 V0 V1 V1 V1 V2 HRC [J / (g·K)] 85 89 87 145 126 138 152 PHRR (W / g) 112 118 115 196 155 182 205 THR (kJ / g) 48 51 49 73 60 68 79 W(%) 35.2 33.7 34.8 15.3 25.6 18.5 12.1 LOI 38.5 37.2 38.0 28.6 32.4 30.1 27.8

[0158] 5. Results and Discussion

[0159] As can be seen from Tables 2-5, the chemical-resistant polycarbonate modified plastics prepared in Examples 1-3 of the present invention have excellent chemical resistance, mechanical properties, thermal properties and flame retardant properties.

[0160] Compared with Examples 1-3, Comparative Example 1 uses an ordinary polycarbonate matrix that has not been modified with siloxane blocks. The ester bonds in its molecular chain are easily hydrolyzed and broken under solvent erosion, and the lack of flexible segments to buffer environmental stress leads to rapid expansion of microcracks within the material, resulting in a sharp deterioration in chemical resistance, a significant decrease in impact toughness, and insufficient resistance to high-temperature deformation.

[0161] Compared with Examples 1-3, Comparative Example 2 uses a conventional acrylate diluent that is not fluorinated and modified, which fails to form a low surface energy barrier layer in the cross-linked network. Solvent molecules easily penetrate along the gaps between polymer chains and induce swelling and deformation, resulting in a significant decrease in the material's light transmittance and an aggravation of surface fogging.

[0162] Compared with Examples 1-3, Comparative Example 3 directly added uncoated modified titanium dioxide microspheres, resulting in weak interface bonding between the filler and the matrix, which easily resulted in debonding defects under stress. This not only weakened the reinforcing and toughening effect of the nanoparticles, but also formed a preferential path for solvent penetration, resulting in simultaneous degradation of mechanical properties and solvent resistance.

[0163] Compared with Examples 1-3, the absence of phosphorus-based radical capturing component in the flame retardant system of Comparative Example 4, which only relies on the char forming of silane groups, results in insufficient gas phase flame retardant efficiency, significantly increased heat release rate and total heat release during combustion, loose residual carbon structure and difficulty in maintaining material integrity.

[0164] In the description of the specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0165] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements to the described specific embodiments or use similar ways to replace, as long as it does not deviate from the invention or exceed the scope defined by the present claims, which shall belong to the protection scope of the present application.

Claims

1. A chemical-resistant polycarbonate modified plastic, characterized in that: It includes the following raw materials in parts by weight: 60-70 parts of modified polycarbonate; 20-25 parts of polyphenylene sulfide; 20-25 parts of solvent-resistant diluent; 8-12 parts of nano-reinforced filler; 2-4 parts of boron nitride nanosheets; 4-6 parts of chopped carbon fiber; 1-2 parts of nano-barium sulfate; 4-6 parts of flame retardant light curing agent; 10-15 parts of chemical resistant toughening agent; 0.5-1 part antioxidant; 0.5-1 part of leveling agent; 0.3-0.5 parts of ultraviolet absorber.

2. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The preparation steps of the modified polycarbonate are as follows: The bisphenol A polycarbonate pellets were vacuum dried and added to an internal mixer together with hydroxyl-terminated polydimethylsiloxane, premixed at 175-185°C for 8-12 minutes, 4,4-diphenylmethane diisocyanate and dibutyltin dilaurate were added, reacted at 175-185°C under nitrogen protection for 12-18 minutes, and then reacted at 190-210°C under nitrogen protection for another 6-10 minutes. The resulting melt was pelletized by a twin-screw extruder to obtain a modified polycarbonate. The mass ratio of the bisphenol A polycarbonate, the terminal hydroxyl polydimethylsiloxane, the 4,4-diphenylmethane diisocyanate and the dibutyltin dilaurate is (55-65):(14-16):(4-6):0.

05.

3. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The preparation steps of the solvent-resistant diluent are as follows: Mix trimethylolpropane triacrylate and tridecafluorooctyltriethoxysilane, add tetraisopropyl titanate and 2,6-di-tert-butyl-p-cresol as polymerization inhibitors, replace with nitrogen three times, react at 75-85°C for 2-3 hours, heat to 95-105°C and reduce pressure to -0.09 MPa for 2-3 hours, filter the product to obtain a solvent-resistant diluent; The mass ratio of the trimethylolpropane triacrylate, tridecafluorooctyltriethoxysilane, tetraisopropyl titanate and 2,6-di-tert-butyl-p-cresol polymerization inhibitor is (68-72):(28.8-31.2):0.3:(0.09-0.11).

4. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The preparation steps of the nano-reinforced filler are as follows: The hollow titanium dioxide microspheres are dispersed in an ethanol solution, γ-methacryloxypropyltrimethoxysilane is added, the pH is adjusted, and the mixture is hydrolyzed at 75-85° C. for 1-2 hours. Multi-walled carbon nanotubes are added and dispersed by ultrasonication, and the mixture is reacted at 100-105° C. for 3-4 hours. The mixture is centrifuged and washed to obtain a nano-reinforced filler. The mass ratio of the hollow titanium dioxide microspheres, γ-methacryloxypropyltrimethoxysilane and multi-walled carbon nanotubes is (35-45):(8-12):(8-12).

5. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The preparation steps of the flame retardant light curing agent are as follows: The preparation steps of flame retardant light curing agent are as follows: Dissolve 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 2-hydroxy-4-(methacryloyloxy)benzophenone in toluene, add dicumyl peroxide, reflux at 100-120° C. for 4-8 hours, rotary evaporate, and dry to obtain a flame retardant light curing agent; The usage ratio of the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-hydroxy-4-(methacryloyloxy)benzophenone, toluene and dicumyl peroxide is (45-55) g: (45-55) g: (250-350) mL: 0.5 g.

6. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The chemical-resistant toughening agent is fluorinated modified polyurethane acrylate.

7. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The boron nitride nanosheets are surface-modified with a KH560 silane coupling agent.

8. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The chopped carbon fibers are surface treated with acid immersion and modified with polydopamine.

9. The chemical-resistant polycarbonate modified plastic according to claim 1, characterized in that: The antioxidant is one or more of a phosphite antioxidant and a hindered phenol antioxidant; the leveling agent is a polyether-modified fluorinated polydimethylsiloxane leveling agent; and the anti-ultraviolet aging agent is a benzotriazole ultraviolet absorber.

10. The preparation method of the chemical-resistant polycarbonate modified plastic according to any one of claims 1 to 9 is as follows: S1. Weigh modified polycarbonate, polyphenylene sulfide, flame retardant light curing agent, antioxidant and ultraviolet absorber by weight, add them into a planetary mixer and stir; weigh and add solvent-resistant diluent by weight and stir, add nano-reinforced filler, boron nitride nanosheets, chopped carbon fiber and nano-barium sulfate and stir; reduce the speed, weigh and add chemical-resistant toughening agent and leveling agent by weight and stir to obtain a premix; S2, transferring the premixed liquid to a three-roll mill for grinding to obtain a premix; placing the premix in a vacuum deaerator for deaeration to obtain a crude resin material; S3. Pour the crude resin material into the resin tank, turn on the DLP light-curing printer, select a 405nm light source, set the light intensity to 12-16mW / cm², import the designed masterbatch model file, and set the layer thickness to 1-10mm. After printing is completed, soak the crude masterbatch in warm water, take it out and let it stand, dry it, put it into a UV curing box for treatment, dry it again, let it stand, and cool it to room temperature to obtain a chemical-resistant polycarbonate modified plastic.