A weather-resistant polycarbonate material, its preparation method and application in plastic pellets

Abstract

The present invention relates to the technical field of polycarbonates, and discloses a weather-resistant polycarbonate material and a preparation method thereof and an application in plastic pellets. The weather-resistant polycarbonate material of the present invention comprises the following components in parts by weight: 100 parts of polycarbonate resin, 10-25 parts of polycarbonate copolymer, and 2-5 parts of fatty acid-modified zinc oxide. The side chains of the polycarbonate copolymer contain flexible and hydrophobic alkyl long chains, which can improve the toughness and hydrophobicity of the polycarbonate material, help improve mechanical properties such as bending strength, and improve water resistance and hydrolysis resistance. The aliphatic alkyl long chains modified on the surface of nano zinc oxide undergo physical chain entanglement with the alkyl long chains of the polycarbonate copolymer side chains, which is conducive to improving the compatibility between zinc oxide and the polycarbonate material, can improve the mechanical properties of the material, and simultaneously improve the anti-ultraviolet aging and weathering resistance of the material.

Description

Technical Field

[0001] The present invention relates to the technical field of polycarbonate, in particular to a weather-resistant polycarbonate material, a preparation method thereof and application in plastic pellets. Background Art

[0002] Polycarbonate has excellent mechanical properties, flame retardancy, and antioxidant properties, making it widely used. However, traditional polycarbonate materials suffer from poor hydrolytic stability, light aging resistance, and weathering resistance, limiting their practical application in outdoor applications. Nanozinc oxide is a readily available, inexpensive inorganic nanomaterial with excellent mechanical properties and UV resistance. When added to polymer resins, it can improve the toughness, strength, UV aging resistance, and weathering resistance of the resin material. Surface modification of nanozinc oxide using fatty acids, polyacrylates, silane coupling agents, and the like can improve its dispersibility and enhance its compatibility with polymer resins. Chinese patent CN114292508B discloses a functional nanozinc oxide-modified polycarbonate sheet and its preparation method. The method involves reacting nanozinc oxide with 2-isocyanatoethyl methacrylate, tris(2-aminoethyl)amine, and maleic anhydride-grafted polypropylene to produce maleic anhydride-grafted polypropylene-modified zinc oxide, which can improve the flexibility, flexural strength, and impact strength of polycarbonate materials. However, this patent does not solve the problem of poor hydrolysis resistance of polycarbonate. Summary of the Invention

[0003] The invention solves the problem of poor mechanical strength, water resistance and weather resistance of polycarbonate.

[0004] The technical solution of the present invention is a weather-resistant polycarbonate material, comprising the following components in parts by weight: 100 parts of polycarbonate resin, 10-25 parts of polycarbonate copolymer, 2-5 parts of fatty acid-modified zinc oxide, and 0.15-0.22 parts of antioxidant.

[0005] Preferably, the preparation method of the weather-resistant polycarbonate material is: adding polycarbonate resin, polycarbonate copolymer, fatty acid-modified zinc oxide, and antioxidant into a mixer and mixing them evenly, then blending and extruding them in an extruder, with the temperature of sections one to six being 210-260°C and the screw speed being 200-250 r / min; and pelletizing to obtain the weather-resistant polycarbonate material.

[0006] Preferably, the preparation method of the carbonate copolymer is:

[0007] (1) The preparation method of N-alkanoylglutamic acid chloride is as follows: dichloromethane solvent, 140-160 parts by weight of thionyl chloride, 100 parts by weight of N-alkanoylglutamic acid, and 6.2-7.6 parts by weight of catalyst N,N-dimethylformamide are added to a reaction vessel equipped with a condenser reflux tube, reacted at 40-45° C. for 4-6 hours, distilled under reduced pressure, and dried to obtain N-alkanoylglutamic acid chloride; the reaction formula is:

[0008]

[0009] (2) Add N,N-dimethylformamide solvent, polycarbonate diol, N-alkanoylglutamic acid chloride, and triethylamine to a reaction vessel, react at 0-5°C for 15-30 minutes, then at 20-30°C for 18-24 hours, pour the solution into water, filter, wash with water and ethanol, and dry to obtain a polycarbonate copolymer. The reaction formula is:

[0010]

[0011] Preferably, in parts by weight, the amount of polycarbonate diol used in (2) is 100 parts, N-alkanoylglutamic acid chloride is 40-46 parts, and triethylamine is 22-25 parts.

[0012] Preferably, the preparation method of fatty acid-modified zinc oxide is as follows: add ethanol, 100 parts by weight of nano zinc oxide, and 5-15 parts by weight of a fatty acid compound to a reaction vessel equipped with a condenser reflux tube, ultrasonically disperse for 1 hour, heat to 70-80°C, react for 1-2 hours, filter, wash with ethanol, and dry to obtain fatty acid-modified zinc oxide.

[0013] Preferably, the fatty acid compound is palmitic acid, myristic acid or stearic acid.

[0014] Preferably, weather-resistant polycarbonate material is used in high-performance plastic pellets.

[0015] The present invention provides beneficial technical effects: A polycarbonate copolymer containing long alkyl chains in its side chains is obtained by polymerizing a polycarbonate diol and N-alkanoylglutamic acid. This copolymer is then melt-co-cured with fatty acid-modified nano-zinc oxide, a polycarbonate resin, and the like, and granulated to produce a weather-resistant polycarbonate material. The polycarbonate copolymer exhibits excellent compatibility with the polycarbonate material, and the flexible and hydrophobic long alkyl chains in its side chains enhance the toughness and hydrophobicity of the polycarbonate material, improving its flexural and impact strength, while also reducing its water absorption, thereby lowering its mass loss rate due to hydrolysis and improving its water resistance and hydrolysis resistance.

[0016] After the nano zinc oxide of the present invention is modified with fatty acids such as stearic acid, its dispersibility is improved and it is not easy to agglomerate. In addition, during the blending process, the aliphatic alkyl long chains modified on the surface of the zinc oxide and the alkyl long chains of the side chains of the polycarbonate copolymer undergo physical chain entanglement, thereby modifying the polycarbonate copolymer on the surface of the nano zinc oxide, which is beneficial to improving the compatibility between the zinc oxide and the polycarbonate material. The nano zinc oxide is uniformly dispersed in the polycarbonate material, which can improve the mechanical properties of the material such as bending strength, and at the same time significantly reduce the color difference value after ultraviolet light aging, thereby improving the material's resistance to ultraviolet aging and weather resistance. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0018] The following polycarbonate resin, model WY-106BR, was purchased from Suzhou Fengjuan Plastic Materials Co., Ltd. Polycarbonate diol, average molecular weight 1000, was purchased from Hubei Xinjiecheng Chemical Technology Co., Ltd. Nano zinc oxide, average particle size 20 nm, was purchased from Ningbo Luofei Nanotechnology Co., Ltd.

[0019] N-stearoyl-L-glutamic acid was prepared according to the method of the article "Synthesis and Gelling Properties of N-stearoyl-L-glutamic Acid and Its Ethyl Ester Derivatives" in the journal "Chemical Journal", Vol. 62, No. 9, 2004, 895-900. The structural formula is

[0020] N-myristoyl glutamic acid was prepared according to the method of Dalian University of Technology's master's thesis "Synthesis and Performance Research of a Series of Amino Acid Surfactants". The structural formula is

[0021] Example 1

[0022] (1) Add 70 mL of dichloromethane solvent, 21 g of thionyl chloride, 15 g of N-stearoyl-L-glutamic acid, and 1.14 g of catalyst N,N-dimethylformamide to a reaction vessel equipped with a condenser reflux tube, react at 40°C for 6 h, distill under reduced pressure, and dry to obtain N-stearoyl glutamic acid chloride. The structural formula is

[0023]

[0024] (2) 500 mL of N,N-dimethylformamide, 50 g of polycarbonate diol, 23 g (51 mmol) of N-stearoyl glutamic acid chloride, and 11.6 g of triethylamine were added to a reaction vessel, and the mixture was reacted at 0°C for 30 min and then at 25°C for 18 h. The solution was poured into water, filtered, washed with water and ethanol, and dried to obtain a polycarbonate copolymer.

[0025] (3) Add 300 mL of ethanol, 20 g of nano zinc oxide, and 2 g of stearic acid to a reaction vessel equipped with a condenser reflux tube, ultrasonically disperse for 1 hour, heat to 70°C, react for 2 hours, filter, wash with ethanol, and dry to obtain fatty acid-modified zinc oxide.

[0026] (4) 1 kg of polycarbonate resin, 100 g of polycarbonate copolymer, 20 g of fatty acid-modified zinc oxide, and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pelletizing was performed to obtain a weather-resistant polycarbonate material.

[0027] Example 2

[0028] (1) Add 80 mL of dichloromethane solvent, 24 g of thionyl chloride, 15 g of N-myristoyl glutamic acid, and 0.93 g of catalyst N,N-dimethylformamide to a reaction vessel equipped with a condenser reflux tube, react at 45°C for 4 h, distill under reduced pressure, and dry to obtain N-myristoyl glutamic acid chloride. The structural formula is

[0029]

[0030] (2) 500 mL of N,N-dimethylformamide, 50 g of polycarbonate diol, 20 g of N-myristoyl glutamic acid chloride, and 12.5 g of triethylamine were added to a reaction vessel, and the mixture was reacted at 5°C for 15 min and then at 20°C for 24 h. The solution was poured into water, filtered, washed with water and ethanol, and dried to obtain a polycarbonate copolymer.

[0031] (3) Add 400 mL of ethanol, 20 g of nano zinc oxide, and 3 g of stearic acid to a reaction vessel equipped with a condenser reflux tube, ultrasonically disperse for 1 hour, heat to 80°C, react for 1 hour, filter, wash with ethanol, and dry to obtain fatty acid-modified zinc oxide.

[0032] (4) 1 kg of polycarbonate resin, 170 g of polycarbonate copolymer, 35 g of fatty acid-modified zinc oxide, and 1.5 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 200 r / min. Pelletizing was performed to obtain a weather-resistant polycarbonate material.

[0033] Example 3

[0034] (1) 600 mL of N,N-dimethylformamide, 50 g of polycarbonate diol, 23 g of N-stearoyl glutamic acid chloride (prepared by Example 1), and 11 g of triethylamine were added to a reaction vessel, and the mixture was reacted at 0° C. for 30 min and then at 30° C. for 18 h. The solution was poured into water, filtered, washed with water and ethanol, and dried to obtain a polycarbonate copolymer.

[0035] (2) Add 300 mL of ethanol, 20 g of nano zinc oxide, and 1 g of stearic acid to a reaction vessel equipped with a condenser reflux tube, ultrasonically disperse for 1 hour, heat to 80°C, react for 1 hour, filter, wash with ethanol, and dry to obtain fatty acid-modified zinc oxide.

[0036] (3) 1 kg of polycarbonate resin, 250 g of polycarbonate copolymer, 50 g of fatty acid-modified zinc oxide, and 2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 200 r / min. Pelletizing was performed to obtain a weather-resistant polycarbonate material.

[0037] Comparative Example 1: The difference between this comparative example and Example 1 is that the polycarbonate copolymer and fatty acid-modified zinc oxide are not added.

[0038] (1) 1 kg of polycarbonate resin and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly, and then blended and extruded in an extruder. The temperatures of sections 1 to 6 were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pellets were cut to obtain a weather-resistant polycarbonate material.

[0039] Comparative Example 2: The difference between this comparative example and Example 1 is that no polycarbonate copolymer is added.

[0040] (1) 1 kg of polycarbonate resin, 20 g of fatty acid-modified zinc oxide, and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pelletizing was performed to obtain a weather-resistant polycarbonate material.

[0041] Comparative Example 3: The difference between this comparative example and Example 1 is that fatty acid-modified zinc oxide is not added.

[0042] (1) 1 kg of polycarbonate resin, 100 g of polycarbonate copolymer, and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pellets were cut to obtain a weather-resistant polycarbonate material.

[0043] Comparative Example 4: The difference between this comparative example and Example 1 is that, when preparing the polycarbonate copolymer, an equal molar amount of glutaryl chloride is used instead of N-stearoyl glutamic acid chloride.

[0044] (1) Add 500 mL of N,N-dimethylformamide, 50 g of polycarbonate diol, 8.5 g (51 mmol) of glutaryl chloride, and 11.6 g of triethylamine to a reaction vessel, react at 0°C for 30 min, then at 25°C for 18 h. Pour the solution into water, filter, wash with water and ethanol, and dry to obtain a polycarbonate copolymer.

[0045] (2) 1 kg of polycarbonate resin, 100 g of polycarbonate copolymer, 20 g of fatty acid-modified zinc oxide, and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pelletizing was performed to obtain a weather-resistant polycarbonate material.

[0046] Comparative Example 5: The difference between this comparative example and Example 1 is that unmodified nano zinc oxide is added.

[0047] (1) 1 kg of polycarbonate resin, 100 g of polycarbonate copolymer, 20 g of nano zinc oxide, and 2.2 g of antioxidant 168 were added to a mixer and mixed evenly. The mixture was then blended and extruded in an extruder. The temperatures for the first to sixth sections were 210° C., 225° C., 245° C., 260° C., and 260° C., and the screw speed was 250 r / min. Pellets were cut to obtain a weather-resistant polycarbonate material.

[0048] The polycarbonate material is made into a sample bar in an injection molding machine, and the temperatures of the first to third sections of the injection molding machine are 220°C, 260°C, and 270°C.

[0049] The bending strength of polycarbonate strips was tested according to the national standard GB / T 9341-2008. The impact strength of polycarbonate strips was tested according to the national standard GB / T1843-2008.

[0050] Polycarbonate strips were prepared into 5cm x 5cm x 2cm specimens, dried in a forced-air dryer at 100°C for 4 hours, and weighed (denoted as m0). The specimens were then immersed in water, heated to 80°C, and allowed to stand for 10 days, with the water changed every 12 hours. The strips were then removed and dried at 100°C for 24 hours, weighed (denoted as m1), and the hydrolysis mass loss rate (W) was calculated. W = (m0 - m1) / m0 × 100%. The lower W, the better the water and hydrolysis resistance.

[0051] The polycarbonate specimens were aged for 720 hours in a UV accelerated aging test chamber (total power of 4.5kW). The color difference before and after UV aging was tested according to the standard ASTM D2244-16. The smaller the color difference, the better the anti-UV aging and weathering performance.

[0052] Table 1 Polycarbonate performance test

[0053]

[0054] According to the results in Table 1, the polycarbonate in Comparative Example 1 has low bending strength and impact strength, poor toughness, a large hydrolysis mass loss rate, poor water resistance and hydrolysis resistance, and a large color difference after UV aging, and poor UV resistance and weathering resistance.

[0055] The polycarbonate materials of Examples 1-3 are modified with polycarbonate copolymers and fatty acid-modified zinc oxide. The polycarbonate copolymers have excellent compatibility with the polycarbonate resin, and the side chains contain flexible and hydrophobic alkyl long chains, which can improve the toughness and hydrophobicity of the polycarbonate resin, thereby improving the flexural strength and impact strength, reducing the water absorption of the polycarbonate material, thereby reducing the hydrolysis mass loss rate, and improving water resistance and hydrolysis resistance. After the nano-zinc oxide is modified with fatty acids such as stearic acid, its dispersibility is improved and it is not easy to agglomerate. In addition, the aliphatic alkyl long chains modified on the surface of the zinc oxide and the alkyl long chains of the polycarbonate copolymer side chains undergo physical chain entanglement during the blending process, thereby modifying the polycarbonate copolymer to the surface of the nano-zinc oxide, which is beneficial to improving the compatibility between the zinc oxide and the polycarbonate material. The nano-zinc oxide is evenly dispersed in the polycarbonate material, which can improve the material's mechanical properties such as flexural strength, and significantly improves its resistance to ultraviolet aging and weathering, with a reduced color difference value after ultraviolet aging.

[0056] Compared with Example 1, Comparative Example 2 does not add polycarbonate copolymer, resulting in poor toughness of the polycarbonate material, low bending strength and impact strength, and poor hydrophobicity, which is not conducive to reducing the water absorption of the polycarbonate material, resulting in a large hydrolysis mass loss rate, poor water resistance and hydrolysis resistance.

[0057] Compared with Example 1, Comparative Example 3 did not add fatty acid-modified zinc oxide, resulting in a larger color difference value of the polycarbonate material after ultraviolet aging, and poor anti-ultraviolet aging and weather resistance.

[0058] Comparative Example 4, using glutaryl chloride as a raw material, produced a polycarbonate copolymer whose side chains lacked flexible and hydrophobic long alkyl chains. This resulted in poor toughening of the polycarbonate material, low impact strength and flexural strength, a high mass loss rate due to hydrolysis, and poor water resistance and hydrolysis resistance. The polycarbonate copolymer was unable to physically entangle with the aliphatic alkyl long chains used to modify the zinc oxide surface, preventing the polycarbonate copolymer from being modified onto the nano-zinc oxide surface. This did not improve the compatibility between zinc oxide and the polycarbonate resin, resulting in mechanical properties such as impact strength being lower than those of Example 1, and a greater color difference than that of Example 1.

[0059] In Comparative Example 4, modified nano zinc oxide is added, which has poor dispersibility and cannot undergo physical chain entanglement with the long-chain alkyl group of the polycarbonate copolymer side chain. The polycarbonate copolymer cannot be modified to the surface of the nano zinc oxide, and the compatibility between zinc oxide and polycarbonate resin is not improved, resulting in the mechanical properties of the polycarbonate material, such as impact strength, being lower than those in Example 1, and the color difference value being greater than that in Example 1.

[0060] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A weather-resistant polycarbonate material, characterized in that: The weather-resistant polycarbonate material comprises the following components in parts by weight: 100 parts of polycarbonate resin, 10-25 parts of polycarbonate copolymer, 2-5 parts of fatty acid-modified zinc oxide, and 0.15-0.22 parts of antioxidant; The fatty acid is stearic acid; The preparation method of the polycarbonate copolymer comprises: adding N,N-dimethylformamide solvent, polycarbonate diol, N-alkanoylglutamic acid chloride, and triethylamine into a reaction container, pouring the solution into water after the reaction, filtering, washing with water and ethanol, and drying to obtain the polycarbonate copolymer; The structural formula of the N-alkanoylglutamic acid chloride is , n is any integer value between 13 and 17.

2. The weather-resistant polycarbonate material according to claim 1, characterized in that: The reaction is first carried out at 0-5°C for 15-30 min and then at 20-30°C for 18-24 h.

3. The weather-resistant polycarbonate material according to claim 1, characterized in that: By weight, the usage of the polycarbonate diol is 100 parts, the usage of N-alkanoylglutamic acid chloride is 40-46 parts, and the usage of triethylamine is 22-25 parts.

4. The weather-resistant polycarbonate material according to claim 1, characterized in that: The preparation method of N-alkanoylglutamic acid chloride comprises: adding dichloromethane solvent, thionyl chloride, N-alkanoylglutamic acid, and catalyst N,N-dimethylformamide into a reaction vessel equipped with a condenser reflux tube, performing reduced pressure distillation after the reaction, and drying to obtain N-alkanoylglutamic acid chloride; The structural formula of the N-alkanoylglutamate is , n is any integer value between 13 and 17.

5. The weather-resistant polycarbonate material according to claim 4, characterized in that: In parts by weight, the amount of the N-alkanoylglutamic acid is 100 parts, the amount of thionyl chloride is 145-160 parts, and the amount of N,N-dimethylformamide is 6.2-7.6 parts.

6. The weather-resistant polycarbonate material according to claim 4, characterized in that: In the preparation method of N-alkanoylglutamic acid chloride, the reaction temperature is 40-45° C. and the reaction time is 4-6 hours.

7. The weather-resistant polycarbonate material according to claim 1, characterized in that: The preparation method of the fatty acid-modified zinc oxide comprises the following steps: adding ethanol, 100 parts by weight of nano zinc oxide, and 5-15 parts by weight of a fatty acid compound into a reaction vessel equipped with a condenser reflux tube, wherein the fatty acid compound is stearic acid; performing ultrasonic dispersion for 1 hour, heating to 70-80° C., reacting for 1-2 hours, filtering, washing with ethanol, and drying to obtain the fatty acid-modified zinc oxide.

8. A method for preparing the weather-resistant polycarbonate material according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: adding polycarbonate resin, polycarbonate copolymer, fatty acid modified zinc oxide and antioxidant into a mixer and mixing them evenly; then blending and extruding them in an extruder; the temperature in sections 1 to 6 is 210-260° C. and the screw speed is 200-250 r / min; and pelletizing is performed to obtain a weather-resistant polycarbonate material.

9. Use of the weather-resistant polycarbonate material obtained by the preparation method according to claim 8 in plastic pellets.

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