A self-healing PC material and its preparation method and application

Abstract

The present invention discloses a self-healing PC material and a preparation method thereof, wherein a polyethylene glycol methacrylate-terminated PC reaction liquid is first prepared, and then a photosensitive monomer is introduced during the preparation process to obtain a notch impact-resistant self-healing PC. The self-healing PC prepared by the present invention improves the shortcomings of the PC material that it is easy to produce stress cracking and high notch impact sensitivity, and the cantilever beam notch impact strength is significantly improved. At the same time, the shortcoming that the PC is easily scratched is also improved. Under ultraviolet light, the photosensitive unit on the molecular chain can achieve self-healing of the PC notch through hydrogen bonding.

Description

Technical Field

[0001] The invention relates to a novel notch impact resistant self-healing PC material and a preparation method and application thereof, belonging to the technical field of polymer materials. Background Art

[0002] Polycarbonate (PC) is an engineering plastic widely used in electronics, automobiles, construction and other fields. PC has excellent mechanical and mechanical properties as well as excellent optical properties. However, it also has disadvantages such as weak resistance to notch impact and weak resistance to scratches. When used in the optical field, the surface is often scratched, resulting in poor use and limited application.

[0003] The prior art usually adopts the method of laminating the PC substrate, specifically covering the surface of the PC optical component with a layer of transparent scratch-resistant film. However, this makes the product production process more complicated, has high requirements for lamination, further increases the cost, and there is a risk of the lamination falling off over time. At the same time, after lamination, the thickness and surface characteristics are prone to change, which in turn has a negative impact on optical properties such as light transmittance. Summary of the invention

[0004] The purpose of the present invention is to provide a novel self-healing PC material, a preparation method thereof and an application thereof. The PC material has good notch impact resistance, self-healing property and long service life.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A self-healing PC material, the structural formula is as follows:

[0007]

[0008] Among them, the -R structure is n is preferably 30-50, and m is preferably 1-15.

[0009] The present invention also provides a method for preparing the self-healing PC, comprising the following steps:

[0010] 1) Mix bisphenol A, alkali solution and sodium hyposulfite to obtain a homogeneous aqueous solution a;

[0011] 2) adding an oil-soluble solvent to the aqueous solution a to obtain an oil-water mixture b;

[0012] 3) continuously introducing phosgene and alkali solution into the mixture b to react;

[0013] 4) adding polyethylene glycol methacrylate, a catalyst, and optional monophenol, and continuously introducing alkali solution to continue the reaction to obtain a polyethylene glycol methacrylate-terminated PC reaction solution;

[0014] 5) taking the oil phase of the reaction solution, removing the oil-soluble solvent after acid washing and water washing to obtain a polyethylene glycol methacrylate-terminated PC solid;

[0015] 6) After the solid is crushed, a certain amount of acryloyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and an initiator are added to obtain a mixture c;

[0016] 7) The mixture c is treated at high temperature to obtain a self-healing PC that is resistant to notch impact.

[0017] Furthermore, in the step 1), the concentration of bisphenol A in the aqueous solution a is 10-20 wt %;

[0018] In the step 1), the alkali is NaOH and / or KOH, and the concentration of the alkali in the aqueous solution a is 4-7wt%. The concentration of the hydrosulfite in the aqueous solution a is 0.1wt%-1wt%; preferably, the hydrosulfite is sodium dithionite.

[0019] Preferably, the reaction temperature of step 1) is 20-40° C., and the reaction time is 10-40 min.

[0020] In the step 2), the oil-soluble solvent may be one or more of chloroform, tetrachloroethane, dichloromethane, chlorobenzene, tetrahydrofuran, dioxane, and pyridine, and the mass ratio of the aqueous solution a to the oil-soluble solvent is 0.5-1.5, preferably 0.9-1.1.

[0021] In the step 3), the molar ratio of phosgene to bisphenol A is 1-2. In the step 3), the reaction time is 5-10 min;

[0022] In the step 3), the concentration of the alkali solution is 5wt%-50wt%, and the alkali can be a strong alkali such as NaOH, KOH, etc., preferably NaOH, which is introduced at a flow rate of 1-10g / min during the reaction.

[0023] In the step 3), the reaction temperature is 15°C-36°C.

[0024] In the step 4), preferably, the catalyst is triethylamine or a quaternary ammonium salt, such as trimethylbenzyl ammonium chloride, octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate, more preferably triethylamine, and the mass content of the catalyst in the reaction solution of step (4) is 50-500 ppm;

[0025] Preferably, the molar ratio of polyethylene glycol methacrylate to bisphenol A is 0.01 to 0.08;

[0026] Preferably, the monophenol may be phenol, p-tert-butylphenol, 2-methoxyphenol or 2-methoxy-4-methylphenol, preferably p-tert-butylphenol, and the molar ratio of the monophenol to bisphenol A is 0 to 0.08;

[0027] Preferably, the base in step 4) can be a strong base such as NaOH, KOH, etc., preferably NaOH, with a concentration of 5wt%-50wt%, preferably 32%, and is introduced at a flow rate of 0.1-1g / min during the reaction;

[0028] Preferably, the reaction temperature of step 4) is 25°C-36°C; and the reaction time is 5-40 min.

[0029] In the step 5), the acid used for pickling can be a strong acid such as hydrochloric acid, sulfuric acid, nitric acid, etc., preferably hydrochloric acid, and the concentration can be 0.5wt%-10wt%, preferably 1wt%;

[0030] The solid product obtained in step 5) has a catalyst content of less than 0.3 ppm, a chloride ion content of less than 10 ppm, and an oil-soluble solvent content of less than 100 ppm.

[0031] Preferably, in step 6), the amount of acrylamide-N-(2-nitrobenzyl)glycinamide photosensitive monomer added is 3wt%-20wt% of the PC solid mass;

[0032] Preferably, the structural formula of the acrylamide-N-(2-nitrobenzyl)glycinamide photosensitive monomer is:

[0033]

[0034] The acrylamide-N-(2-nitrobenzyl)glycinamide photosensitive monomer is prepared by the method described in patent CN112552204A.

[0035] Preferably, the initiator can be an azo initiator such as azobisisobutyronitrile (AIBN), azobisisoheptanenitrile (ABVN), or an organic peroxide initiator such as benzoyl peroxide (BPO), tert-butyl benzoyl peroxide, methyl ethyl ketone peroxide, etc. AIBN is preferably used as the initiator, and the amount used is 0.5% to 3% of the mass of the acryloyl-N-(2-nitrobenzyl) glycinamide photosensitive monomer.

[0036] In the step 7), preferably, the mixture c is added into a high-temperature mold for treatment at a temperature of 250° C. to 350° C. and a heat preservation time of 10 min to 120 min.

[0037] The present invention also provides application of the novel notch impact resistant self-healing PC in sunscreen materials.

[0038] Compared with the prior art, the present invention has the following advantages:

[0039] 1) A new type of self-healing PC material with notch impact resistance was prepared. By using polyethylene glycol methacrylate as a cross-linking agent, polyethylene glycol methacrylate undergoes a polycondensation reaction with phosgene during the polymerization process based on the hydroxyl group, and undergoes a free radical polymerization reaction based on the carbon-carbon double bond during the processing process, so that the cross-linking is performed without affecting the processing performance of PC, so that the cantilever beam notch impact strength is increased to 20-60 kJ / m 2 , while achieving stronger notch impact resistance.

[0040] 2) Due to the addition of acrylyl-N-(2-nitrobenzyl) glycinamide photosensitive monomer in the material, after scratching the surface of PC products, the scratched surface of the products can be restored to its original state through treatment methods such as light exposure;

[0041] 3) Compared with the existing technology, this technology is the first to use a new type of self-healing PC that is resistant to notch impact, and to design and transform PC from the molecular structure. Compared with other secondary processing technologies such as current coating, it greatly improves the mechanical properties of PC while having stronger stability. DETAILED DESCRIPTION

[0042] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0043] In the embodiments, the notched cantilever beam impact strength is tested according to GB / T1843-2008, and the tensile strength is tested according to GB / T1040-1992.

[0044] Raw material source: Polyethylene glycol methacrylate (manufacturer: Aladdin, CAS: 25736-86-1, molecular weight: 220)

[0045] Trimethylbenzyl ammonium chloride (Manufacturer: Aladdin, CAS: 56-93-9, molecular weight 185.69)

[0046] Octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate (Manufacturer: Aladdin, CAS: 86443-82-5, molecular weight 404.03)

[0047] Triethylamine (Manufacturer: Tianjin Komeo, CAS: 121-44-8, molecular weight 101.1918)

[0048] Acryloyl-N-(2-nitrobenzyl) glycinamide photosensitive monomer was prepared by the method described in patent CN112552204A. The specific method is as follows: 8.4g N-acryloylglycine, 15.4g N,N'-dicyclohexylcarbodiimide (DCC) and 1000ml dichloromethane were added to a round-bottom flask, and stirred with magnetic force in an ice bath at 0°C until completely dispersed and no more monomer blocks were formed. 7.4g N-hydroxysuccinimide (NHS) was weighed, added to the above solution, and stirred at room temperature of 25°C for 10 hours to obtain a white suspension. The reaction solution was filtered, the white insoluble matter was discarded, 4.7g 2-nitrobenzylamine hydrochloride was added to the colorless filtrate, and 20ml triethylamine solution was added dropwise, and stirred at room temperature for 16 hours. After the reaction is completed, the dichloromethane solvent is removed by rotary evaporation, 6000 ml of ethyl acetate solution is added to the obtained solid, stirred at room temperature for 4 hours, filtered, and the filtrate is rotary evaporated to dryness to obtain a yellow solid, which is placed in a constant temperature drying oven at 37°C to obtain the final product.

[0049] [Example 1]

[0050] Add 540g of deionized water to a 2L jacketed reactor under nitrogen protection, then add 31g of solid NaOH and stir to dissolve. Adjust the temperature to 32°C, add 1g of sodium hypochlorite and 80g of bisphenol A solid, stir for 30min until bisphenol A is completely dissolved, and obtain a homogeneous aqueous solution;

[0051] Add 650g of dichloromethane to the reactor and adjust the speed to 300r / min to mix the water phase and the oil phase evenly;

[0052] 9.4 L of phosgene gas was introduced into the reactor at a rate of 0.94 L / min, and 32 wt% of NaOH lye was added into the reactor at a rate of 1.9 g / min, during which the reaction temperature was controlled at 35°C;

[0053] Add 4.8 g of polyethylene glycol methacrylate and 78 ppm of triethylamine to the reactor, and at the same time add 32 wt % of NaOH solution to the reactor at a rate of 0.28 g / min, and stir continuously for 30 min before stopping. During this period, the reaction temperature is controlled at 28 ° C.

[0054] After the water and oil phases were separated, the oil phase was first washed with 1.5% HCl solution, and then washed with deionized water until the water after washing was neutral. Then, the MC was removed and dried to obtain a polyethylene glycol methacrylate-terminated PC solid;

[0055] The polyethylene glycol methacrylate-terminated PC solid was crushed and 100 g was taken, 8.3 g of acrylyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and 3 wt% of dibenzoyl peroxide by weight of the photosensitive monomer were added and mixed evenly;

[0056] Use a flat plate vulcanizer at 300°C to press it into a 3mm plate and keep it warm for 40 minutes.

[0057] The tested cantilever beam notched impact strength is 32kJ / m 2 .

[0058] According to GB / T 1040-1992, a tensile specimen was prepared, and a scratch with a depth of 1 mm was made in the middle of the neck using a blade. The tensile strength was tested to be 23 MPa. After the scratched tensile specimen was irradiated with ultraviolet light for 10 minutes, the tensile strength was tested to be 52 MPa (the tensile strength of the unscratched tensile specimen was 96 MPa), and the repair rate was 54%.

[0059] [Example 2]

[0060] Add 540g of deionized water to a 2L jacketed reactor under nitrogen protection, then add 32g of solid NaOH and stir to dissolve. Adjust the temperature to 32°C, add 5g of sodium hydrosulfite and 80g of bisphenol A solid, stir for 30min until bisphenol A is completely dissolved, and obtain a homogeneous aqueous solution;

[0061] Add 650g of dichloromethane to the reactor and adjust the speed to 300r / min to mix the water phase and the oil phase evenly;

[0062] 11.2 L of phosgene gas was introduced into the reactor at a rate of 1.12 L / min, and 32 wt% of NaOH alkali solution was added into the reactor at a rate of 1.9 g / min, during which the reaction temperature was controlled at 35 °C;

[0063] Add 4.8 g of polyethylene glycol methacrylate and 78 ppm of trimethylbenzyl ammonium chloride to the reactor, and at the same time add 32 wt % of NaOH solution to the reactor at a rate of 0.28 g / min, and stir continuously for 30 min before stopping. During this period, the reaction temperature is controlled at 28 ° C.

[0064] After the water and oil phases were separated, the oil phase was first washed with 1.5% HCl solution, and then washed with deionized water until the water after washing was neutral. Then, the MC was removed and dried to obtain a polyethylene glycol methacrylate-terminated PC solid;

[0065] The polyethylene glycol methacrylate-terminated PC solid was crushed and 100 g was taken, 16.6 g of acrylyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and 0.8 wt% of dibenzoyl peroxide by weight of the photosensitive monomer were added and mixed evenly;

[0066] Use a flat plate vulcanizer at 300°C to press it into a 3mm plate and keep it warm for 40 minutes.

[0067] The tested cantilever beam notched impact strength is 32kJ / m 2 .

[0068] According to GB / T 1040-1992, a tensile specimen was prepared, and a scratch with a depth of 1 mm was made in the middle of the neck using a blade. The tensile strength was tested to be 23 MPa. After the scratched tensile specimen was irradiated with ultraviolet light for 10 minutes, the tensile strength was tested to be 63 MPa (the tensile strength of the unscratched tensile specimen was 96 MPa), and the repair rate was 65%.

[0069] [Example 3]

[0070] Add 540g of deionized water to a 2L jacketed reactor under nitrogen protection, then add 31g of solid NaOH and stir to dissolve. Adjust the temperature to 32°C, add 1g of sodium hypochlorite and 80g of bisphenol A solid, stir for 30min until bisphenol A is completely dissolved, and obtain a homogeneous aqueous solution;

[0071] Add 650g of dichloromethane to the reactor and adjust the speed to 300r / min to mix the water phase and the oil phase evenly;

[0072] 13.4 L of phosgene gas was introduced into the reactor at a rate of 1.34 L / min, and 32 wt% of NaOH alkali solution was added into the reactor at a rate of 1.9 g / min, during which the reaction temperature was controlled at 35°C;

[0073] 2.7 g of polyethylene glycol methacrylate, 15.8 g of 10 wt% PTBP solution, and 150 ppm of octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate were added to the reactor, and 32 wt% of NaOH solution was added to the reactor at a rate of 0.28 g / min. The mixture was stirred for 30 min and then stopped. During the stirring, the reaction temperature was controlled at 28°C.

[0074] After the water and oil phases were separated, the oil phase was first washed with 1.5% HCl solution, and then washed with deionized water until the water after washing was neutral. Then, the MC was removed and dried to obtain a polyethylene glycol methacrylate-terminated PC solid;

[0075] The polyethylene glycol methacrylate-terminated PC solid was crushed and 100 g was taken, 10.6 g of acrylyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and 0.8 wt% of dibenzoyl peroxide by weight of the photosensitive monomer were added and mixed evenly;

[0076] Use a flat plate vulcanizer at 300°C to press it into a 3mm plate and keep it warm for 40 minutes.

[0077] The tested cantilever beam notched impact strength is 32kJ / m 2 .

[0078] According to GB / T 1040-1992, a tensile specimen was prepared. A scratch with a depth of 1 mm was made in the middle of the neck using a blade. The tensile strength was tested to be 23 MPa. After the scratched tensile specimen was irradiated with ultraviolet light for 10 minutes, the tensile strength was tested to be 95 MPa (the tensile strength of the unscratched tensile specimen was 96 MPa), and the repair rate was 99%.

[0079] [Example 4]

[0080] Add 540g of deionized water to a 2L jacketed reactor under nitrogen protection, then add 31g of solid NaOH and stir to dissolve. Adjust the temperature to 32°C, add 1g of sodium hypochlorite and 80g of bisphenol A solid, stir for 30min until bisphenol A is completely dissolved, and obtain a homogeneous aqueous solution;

[0081] Add 650g of dichloromethane to the reactor and adjust the speed to 300r / min to mix the water phase and the oil phase evenly;

[0082] 9.4 L of phosgene gas was introduced into the reactor at a rate of 0.94 L / min, and 32 wt% of NaOH lye was added into the reactor at a rate of 1.9 g / min, during which the reaction temperature was controlled at 35°C;

[0083] 3.6 g of polyethylene glycol methacrylate, 4.7 g of 10 wt% PTBP solution, and 300 ppm of triethylamine were added to the reactor. At the same time, 32 wt% NaOH solution was added to the reactor at a rate of 0.28 g / min. The mixture was stirred for 30 min and then stopped. During the stirring, the reaction temperature was controlled at 28°C.

[0084] After the water and oil phases were separated, the oil phase was first washed with 1.5% HCl solution, and then washed with deionized water until the water after washing was neutral. Then, the MC was removed and dried to obtain a polyethylene glycol methacrylate-terminated PC solid;

[0085] The polyethylene glycol methacrylate-terminated PC solid was crushed and 100 g was taken, 16.6 g of acrylyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and 1 wt% of dibenzoyl peroxide were added and mixed evenly;

[0086] Use a flat plate vulcanizer at 300°C to press it into a 3mm plate and keep it warm for 40 minutes.

[0087] The tested cantilever beam notched impact strength is 32kJ / m 2 .

[0088] According to GB / T 1040-1992, a tensile specimen was prepared, and a scratch with a depth of 1 mm was made in the middle of the neck using a blade. The tensile strength was tested to be 23 MPa. After the scratched tensile specimen was irradiated with ultraviolet light for 10 minutes, the tensile strength was tested to be 84 MPa (the tensile strength of the unscratched tensile specimen was 96 MPa), and the repair rate was 87%.

Claims

1. A self-healing PC material, characterized in that: The structural formula is as follows: Among them, the R structure is n=30-50, m is 1-15.

2. The method for preparing the self-healing PC according to claim 1, characterized in that: The following steps are involved: 1) Mix bisphenol A, alkali solution and sodium hyposulfite to obtain a homogeneous aqueous solution a; 2) adding an oil-soluble solvent to the aqueous solution a to obtain an oil-water mixture b; 3) continuously introducing phosgene and alkali solution into the mixture b to react; 4) adding polyethylene glycol methacrylate, a catalyst, and optional monophenol, and continuously introducing alkali solution to continue the reaction to obtain a polyethylene glycol methacrylate-terminated PC reaction solution; 5) taking the oil phase of the reaction solution, removing the oil-soluble solvent after acid washing and water washing to obtain a polyethylene glycol methacrylate-terminated PC solid; 6) After the solid is crushed, a certain amount of acryloyl-N-(2-nitrobenzyl)glycinamide photosensitive monomer and an initiator are added to obtain a mixture c; 7) The mixture c is treated at high temperature to obtain a self-healing PC that is resistant to notch impact.

3. The preparation method according to claim 2, characterized in that: In the step 1), the concentration of bisphenol A in the aqueous solution a is 10-20 wt %.

4. The preparation method according to claim 2, characterized in that: In the step 1), the base is NaOH and / or KOH, and the concentration of the base in the aqueous solution a is 4-7 wt %.

5. The preparation method according to claim 2, characterized in that: The hydrosulfite is sodium dithionite, and the concentration of the hydrosulfite in the aqueous solution a is 0.1wt%-1wt%.

6. The preparation method according to claim 2, characterized in that: The reaction temperature of step 1) is 20-40°C, and the reaction time is 10-40 minutes.

7. The preparation method according to claim 2, characterized in that: In the step 2), the oil-soluble solvent is one or more of chloroform, tetrachloroethane, dichloromethane, chlorobenzene, tetrahydrofuran, dioxane, and pyridine.

8. The preparation method according to claim 2, characterized in that: The mass ratio of the aqueous solution a to the oil-soluble solvent is 0.5-1.

5.

9. The preparation method according to claim 8, characterized in that: The mass ratio of the aqueous solution a to the oil-soluble solvent is 0.9-1.

1.

10. The preparation method according to claim 2, characterized in that: In the step 3), the molar ratio of phosgene to bisphenol A is 1-2.

11. The preparation method according to claim 2, characterized in that: In the step 3), the reaction time is 5-10 min; the reaction temperature is 15° C.-36° C.

12. The preparation method according to claim 2, characterized in that: In the step 3), the concentration of the alkali solution is 5wt%-50wt%, and the alkali is NaOH or KOH which is introduced into the reaction at a flow rate of 1-10g / min.

13. The preparation method according to claim 2, characterized in that: In the step 4), the catalyst is triethylamine or a quaternary ammonium salt.

14. The preparation method according to claim 13, characterized in that: In the step 4), the catalyst is trimethylbenzyl ammonium chloride, octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate or triethylamine.

15. The preparation method according to claim 2, characterized in that: The mass content of the catalyst in the reaction solution of step (4) is 50-500 ppm.

16. The preparation method according to claim 2, characterized in that: The molar ratio of polyethylene glycol methacrylate to bisphenol A is 0.01 to 0.

08.

17. The preparation method according to claim 2, characterized in that: The monophenol is selected from phenol, p-tert-butylphenol, 2-methoxyphenol or 2-methoxy-4-methylphenol.

18. The preparation method according to claim 17, characterized in that: The monophenol is p-tert-butylphenol.

19. The preparation method according to claim 2, characterized in that: The molar ratio of the monophenol to bisphenol A is 0 to 0.

08.

20. The preparation method according to claim 2, characterized in that: The base in step 4) is NaOH or KOH with a concentration of 5wt%-50wt%, and is introduced at a flow rate of 0.1-1g / min during the reaction.

21. The preparation method according to claim 2, characterized in that: The reaction temperature of step 4) is 25°C-36°C; the reaction time is 5-40min.

22. The preparation method according to claim 2, characterized in that: In the step 5), the acid used for pickling is hydrochloric acid, sulfuric acid or nitric acid.

23. The preparation method according to claim 2, characterized in that: The structural formula of the acrylamide-N-(2-nitrobenzyl)glycinamide photosensitive monomer is:

24. The preparation method according to claim 2, characterized in that: In the step 6), the amount of acrylamide-N-(2-nitrobenzyl)glycinamide photosensitive monomer added is 3 wt%-20 wt% of the PC solid mass.

25. The preparation method according to claim 2, characterized in that: The initiator is an azo initiator or an organic peroxide initiator.

26. The preparation method according to claim 25, characterized in that: The initiator was AIBN.

27. The preparation method according to claim 2, characterized in that: The amount of the initiator used is 0.5% to 3% of the mass of the acryl-N-(2-nitrobenzyl) glycinamide photosensitive monomer.

28. The preparation method according to claim 2, characterized in that: In the step 7), the mixture c is added into a high temperature mold for treatment at a temperature of 250° C. to 350° C. and a heat preservation time of 10 min to 120 min.

29. Use of the self-healing PC according to claim 1 or the self-healing PC prepared by the preparation method according to any one of claims 2 to 28 in sunscreen materials.

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