Hydrolysis-resistant PC material and preparation method thereof
By introducing amino-modified nano-silica and nano-titanium dioxide into polycarbonate materials and combining them with glycidyl methacrylate-grafted polyethylene, a hydrolysis-resistant PC material is formed, which solves the problem of hydrolysis of polycarbonate under the action of heat and water, and improves the hydrolysis resistance and mechanical properties of the material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-31
- Publication Date
- 2026-04-10
AI Technical Summary
Polycarbonate materials are prone to hydrolysis under the influence of heat and water, which leads to a decrease in the transparency and toughness of the material, limiting its application in food and beverage containers and other fields.
By reacting succinic anhydride-terminated polydimethylsiloxane with amino nano-silica and amino nano-titanium dioxide in a solvent, carboxylsilane-grafted nanoparticles are generated. These nanoparticles are then melt-extruded with glycidyl methacrylate-grafted polyethylene and subsequently mixed with polycarbonate to form a hydrolysis-resistant PC material.
It improves the hydrolysis resistance of polycarbonate materials, enhances the dispersion uniformity and cross-linking degree of modified nanoparticles in the polycarbonate matrix, effectively resists moisture intrusion, and improves the mechanical properties and heat resistance of the materials.
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Abstract
Description
Technical Field
[0001] This invention relates to a hydrolysis-resistant PC material and its preparation method, belonging to the field of polymer materials technology. Background Technology
[0002] Polycarbonate is a general term for polymers whose main molecular chain contains carbonate groups. Based on different main chain structures, it can be divided into aliphatic, alicyclic, and aromatic polycarbonates. Polycarbonate is an engineering material with excellent physical and chemical properties, such as excellent transparency, high mechanical strength, good thermal stability, and high heat distortion temperature. It is widely used in food contact packaging, medical devices, optical components, and the construction and transportation industries. When used as food and beverage containers, the ester bonds in the polycarbonate molecular chain hydrolyze under heat and water, causing the macromolecules to degrade, leading to a decrease in the material's transparency and toughness, thus limiting its applications.
[0003] Therefore, in order to improve the heat and water resistance of polycarbonate and broaden its application range, there is an urgent need to provide a hydrolysis-resistant PC material and its preparation method. Summary of the Invention
[0004] The purpose of this invention is to provide a stress-resistant polypropylene that can prevent whitening, thereby solving the problem that polypropylene materials are prone to whitening when subjected to stress, which affects their appearance and mechanical properties.
[0005] This invention provides a method for preparing hydrolysis-resistant PC material, comprising the following steps: (1) Succinic anhydride-terminated polydimethylsiloxane, amino nano-silica, and amino nano-titanium dioxide are mixed and reacted in a solvent at 90-95°C to obtain carboxylsilane-grafted nanoparticles; the sum of the amino molar amounts of the amino nano-silica and amino nano-titanium dioxide is equal to the anhydride molar amount of the succinic anhydride-terminated polydimethylsiloxane; the mass ratio of the amino nano-silica to the amino nano-titanium dioxide is 0.6-0.8:1.2-1.5; (2) Modified nanoparticles were obtained by melt extrusion of carboxysilane-grafted nanoparticles and glycidyl methacrylate-grafted polyethylene. (3) Polycarbonate and modified nanoparticles are melt-extruded to obtain hydrolysis-resistant PC material.
[0006] Preferably, the preparation method of the amino nano silica is as follows: nano silica, ethanol and water are mixed to obtain a dispersion, concentrated ammonia and 3-aminopropyltrimethoxysilane are added to the dispersion, and the mixture is reacted at 75~80℃ for 10~12h to obtain amino nano silica.
[0007] Preferably, for every 2g of nano-silica, the volume of concentrated ammonia water used is 5~6mL, and the volume of 3-aminopropyltrimethoxysilane is 1~1.5mL.
[0008] Preferably, the preparation method of the amino nano-titanium dioxide is as follows: nano-titanium dioxide, ethanol and water are mixed to obtain a dispersion, concentrated ammonia and 3-aminopropyltrimethoxysilane are added to the dispersion, and the mixture is reacted at 75~80℃ for 10~12h to obtain amino nano-titanium dioxide.
[0009] Preferably, for every 2g of nano-titanium dioxide, the volume of concentrated ammonia water used is 5-6mL, and the volume of 3-aminopropyltrimethoxysilane is 1-1.5mL.
[0010] Preferably, the viscosity of the succinic anhydride-terminated polydimethylsiloxane at 25°C is 75~100 cSt.
[0011] Preferably, the mixing reaction time in step (1) is 12-15 hours.
[0012] Preferably, the mass ratio of the carboxysilane-grafted nanoparticles to the glycidyl methacrylate-grafted polyethylene is 30~40:80~90; the melt index of the glycidyl methacrylate-grafted polyethylene at a temperature of 190℃ and a load of 2.16kg is 4.5~7.5g / 10min, and the grafting rate is 0.5~0.6%; the melt extrusion temperature in step (2) is 200~220℃.
[0013] Preferably, the mass ratio of polycarbonate to modified nanoparticles is 100:20~30; the melt extrusion temperature in step (3) is 250~260℃, and the melt flow rate of polycarbonate is 10~12 g / min. This invention provides a method for preparing hydrolysis-resistant PC material as described above, resulting in a hydrolysis-resistant PC material.
[0014] The beneficial effects of this invention are as follows: First, nano-silica and nano-titanium dioxide are modified with amino groups. Then, using the amidation reaction between amino groups and acid anhydrides, succinic anhydride-terminated polydimethylsiloxane is chemically bonded to the surface of nano-silica and nano-titanium dioxide, thereby introducing long organosilicon segments onto the surface of the nanoparticles and improving the hydrophobicity of the system. Finally, using the chemical bonding reaction between carboxyl groups and glycidyl esters, glycidyl methacrylate grafted polyethylene is further introduced onto the surface of the nanoparticles, improving the compatibility between the nanoparticles and the polycarbonate matrix, and thus improving the dispersion uniformity of the modified nanoparticles in the polycarbonate matrix. The uniformly dispersed modified nanoparticles generate physical interlocking and mechanical interlocking through the surface-grafted polyethylene segments and organosilicon segments, improving the degree of crosslinking of the system. The hydrophobic network crosslinking structure can effectively resist the intrusion of water and improve the hydrolysis resistance of the polycarbonate material. Detailed Implementation
[0015] The following examples are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the present invention. Example
[0016] The preparation method of the hydrolysis-resistant PC material in this embodiment includes the following steps: (1) 2.0 g of nano silica was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 10 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano silica.
[0017] (2) 2.0 g of nano titanium dioxide was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 10 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano titanium dioxide.
[0018] (3) Add 1g of succinic anhydride-terminated polydimethylsiloxane (viscosity of 75~100cSt at 25℃) to 100mL of N,N-dimethylformamide and stir evenly to obtain a succinic anhydride-terminated polydimethylsiloxane solution; add 0.6g of amino nano-silica and 1.5g of amino nano-titanium dioxide to 180mL of N,N-dimethylformamide and ultrasonically disperse evenly to obtain a nanoparticle dispersion. Then pour the nanoparticle dispersion into a three-necked flask, stir at 600rpm, heat to 90℃, and then add succinic anhydride. The end-capped polydimethylsiloxane solution was added dropwise to a three-necked flask (the sum of the amino molar amounts of amino nano-silica and amino nano-titanium dioxide in the nanoparticle dispersion was equal to the anhydride molar amount of succinic anhydride-capped polydimethylsiloxane). After the addition was completed, the reaction was stirred for 12 hours. After cooling to room temperature, the mixture was centrifuged at 10,000 rpm for 10 minutes. The solid obtained by centrifugation was washed three times with N,N-dimethylformamide and ethanol, and then vacuum dried to constant weight to obtain carboxylsilane-grafted nanoparticles.
[0019] (4) Carboxysilane grafted nanoparticles with a mass ratio of 30:80 and glycidyl methacrylate grafted polyethylene (melt index of 4.5 g / 10 min and grafting rate of 0.5% under the conditions of temperature of 190℃ and load of 2.16 kg) were stirred evenly and added to a twin-screw extruder. The mixture was melt-extruded and granulated at 200℃ to obtain modified nanoparticles.
[0020] (5) PC resin (melt flow rate of 10 g / min) and modified nanoparticles are added to a twin-screw extruder at a mass ratio of 100:20 and melt extruded and granulated at 250°C to obtain hydrolysis resistant PC material. Example
[0021] The preparation method of the hydrolysis-resistant PC material in this embodiment includes the following steps: (1) 2.0 g of nano silica was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 10-12 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano silica.
[0022] (2) 2.0 g of nano titanium dioxide was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 10-12 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano titanium dioxide.
[0023] (3) Add 1g of succinic anhydride-terminated polydimethylsiloxane (viscosity 75~100cSt at 25℃) to 100mL of N,N-dimethylformamide, stir evenly to obtain a succinic anhydride-terminated polydimethylsiloxane solution; add 0.6~0.8g of amino nano-silica and 1.2~1.5g of amino nano-titanium dioxide to 180mL of N,N-dimethylformamide, ultrasonically disperse evenly to obtain a nanoparticle dispersion, then pour the nanoparticle dispersion into a three-necked flask, stir at 600rpm, heat to 90~95℃, and then... The succinic anhydride-terminated polydimethylsiloxane solution was added dropwise to a three-necked flask (the sum of the amino molar amounts of amino nano-silica and amino nano-titanium dioxide in the nanoparticle dispersion was equal to the anhydride molar amount of succinic anhydride-terminated polydimethylsiloxane). After the addition was completed, the mixture was stirred for 12-15 hours. After cooling to room temperature, the mixture was centrifuged at 10,000 rpm for 10 minutes. The solid obtained by centrifugation was washed three times with N,N-dimethylformamide and ethanol, and then vacuum dried to constant weight to obtain carboxylsilane-grafted nanoparticles.
[0024] (4) Carboxysilane grafted nanoparticles with a mass ratio of 30~40:80~90 and glycidyl methacrylate grafted polyethylene (melt index of 4.5~7.5g / 10min and grafting rate of 0.5~0.6% under the conditions of temperature of 190℃ and load of 2.16kg) are stirred evenly and then added to a twin-screw extruder. The mixture is melt-extruded and granulated at 200~220℃ to obtain modified nanoparticles.
[0025] (5) PC resin (melt flow rate of 10 g / min) and modified nanoparticles are added to a twin-screw extruder at a mass ratio of 100:20~30 and melt extruded and granulated at 250~260℃ to obtain hydrolysis resistant PC material. Example
[0026] The preparation method of the hydrolysis-resistant PC material in this embodiment includes the following steps: (1) 2.0 g of nano silica was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano silica.
[0027] (2) 2.0 g of nano titanium dioxide was added to a mixed solution consisting of 180 mL of ethanol and 25 mL of deionized water. The mixture was sonicated for 10 min to obtain a dispersion. The dispersion was poured into a three-necked flask and stirred at 500 rpm for 30 min at 75 °C. Then, 5 mL of concentrated ammonia and 1 mL of 3-aminopropyltrimethoxysilane were added dropwise to the dispersion. The mixture was stirred and refluxed at 75 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature and then centrifuged at 10000 rpm for 10 min. The solid obtained by centrifugation was washed three times with deionized water and ethanol, and then vacuum dried to constant weight to obtain amino nano titanium dioxide.
[0028] (3) Add 1g of succinic anhydride-terminated polydimethylsiloxane (viscosity of 75~100cSt at 25℃) to 100mL of N,N-dimethylformamide and stir evenly to obtain a succinic anhydride-terminated polydimethylsiloxane solution; add 0.8g of amino nano-silica and 1.2g of amino nano-titanium dioxide to 180mL of N,N-dimethylformamide and ultrasonically disperse evenly to obtain a nanoparticle dispersion. Then pour the nanoparticle dispersion into a three-necked flask, stir at 600rpm, heat to 95℃, and then add succinic anhydride. The end-capped polydimethylsiloxane solution was added dropwise to a three-necked flask (the sum of the amino molar amounts of amino nano-silica and amino nano-titanium dioxide in the nanoparticle dispersion was equal to the anhydride molar amount of succinic anhydride-capped polydimethylsiloxane). After the addition was completed, the reaction was stirred for 15 hours. After cooling to room temperature, the mixture was centrifuged at 10,000 rpm for 10 minutes. The solid obtained by centrifugation was washed three times with N,N-dimethylformamide and ethanol, and then vacuum dried to constant weight to obtain carboxylsilane-grafted nanoparticles.
[0029] (4) Carboxysilane grafted nanoparticles with a mass ratio of 40:90 and glycidyl methacrylate grafted polyethylene (melt index of 7.5 g / 10 min and grafting rate of 0.6% under the conditions of temperature of 190℃ and load of 2.16 kg) were stirred evenly and added to a twin-screw extruder. The mixture was melt-extruded and granulated at 220℃ to obtain modified nanoparticles.
[0030] (5) PC resin (melt flow rate of 10 g / min) and modified nanoparticles are added to a twin-screw extruder at a mass ratio of 100:30 and melt extruded and granulated at 260°C to obtain hydrolysis-resistant PC material.
[0031] Comparative Example 1 The only difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is that the modified nanoparticles in step (5) of the preparation method of the hydrolysis-resistant PC material in this comparative example are composed of nano-silica, nano-titanium dioxide and glycidyl methacrylate grafted polyethylene. The mass ratio of nano-silica to nano-titanium dioxide is 0.6:1.5, and the mass ratio of the sum of the masses of nano-silica and nano-titanium dioxide to the mass of glycidyl methacrylate grafted polyethylene is 30:80. The nano-silica is the same as the nano-silica in step (1) of Example 1, the nano-titanium dioxide is the same as the nano-titanium dioxide in step (2) of Example 1, and the glycidyl methacrylate grafted polyethylene is the same as the glycidyl methacrylate grafted polyethylene in step (4) of Example 1.
[0032] Comparative Example 2 The only difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is that the modified nanoparticles in step (5) of the preparation method of the hydrolysis-resistant PC material in this comparative example are composed of amino nano silica, amino nano titanium dioxide and glycidyl methacrylate grafted polyethylene. The mass ratio of amino nano silica and amino nano titanium dioxide is 0.6:1.5, and the mass ratio of the sum of the masses of amino nano silica and amino nano titanium dioxide to the mass of glycidyl methacrylate grafted polyethylene is 30:80. The amino nano silica is the same as the amino nano silica in step (1) of Example 1, the amino nano titanium dioxide is the same as the amino nano titanium dioxide in step (2) of Example 1, and the glycidyl methacrylate grafted polyethylene is the same as the glycidyl methacrylate grafted polyethylene in step (4) of Example 1.
[0033] Comparative Example 3 The difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is that the preparation method of the modified nanoparticles in step (5) of the preparation method of the hydrolysis-resistant PC material in this comparative example is as follows: amino nano silica, amino nano titanium dioxide and glycidyl methacrylate grafted polyethylene are stirred evenly and then added to a twin-screw extruder. The mixture is melt-extruded and granulated at 200°C to obtain modified nanoparticles. The mass ratio of amino nano silica and amino nano titanium dioxide is 0.6:1.5, and the mass ratio of the sum of the mass of amino nano silica and amino nano titanium dioxide to the mass of glycidyl methacrylate grafted polyethylene is 30:80. The amino nano silica is the same as the amino nano silica in step (1) of Example 1, the amino nano titanium dioxide is the same as the amino nano titanium dioxide in step (2) of Example 1, and the glycidyl methacrylate grafted polyethylene is the same as the glycidyl methacrylate grafted polyethylene in step (4) of Example 1.
[0034] Comparative Example 4 The difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is only that the preparation method of the carboxylsilane grafted nanoparticles in step (3) of the preparation method of the hydrolysis-resistant PC material in this comparative example is as follows: 1g of succinic anhydride-terminated polydimethylsiloxane (viscosity of 75~100cSt at 25℃) is added to 100mL of N,N-dimethylformamide and stirred evenly to obtain a succinic anhydride-terminated polydimethylsiloxane solution; 0.6g of amino nano-silica and 1.5g of amino nano-titanium dioxide are added to 180mL of N,N-dimethylformamide and ultrasonically dispersed evenly to obtain a nanoparticle dispersion, and then... The nanoparticle dispersion was poured into a three-necked flask and stirred at 600 rpm. After heating to 90°C, the succinic anhydride-terminated polydimethylsiloxane solution was added dropwise to the three-necked flask (the sum of the amino molar amounts of amino nano-silica and amino nano-titanium dioxide in the nanoparticle dispersion was equal to the anhydride molar amount of succinic anhydride-terminated polydimethylsiloxane). After the addition was completed, the reaction was stirred for 12 h. After cooling to room temperature, the mixture was centrifuged at 10,000 rpm for 10 min. The solid obtained by centrifugation was washed three times with N,N-dimethylformamide and ethanol, and then vacuum dried to constant weight to obtain carboxylsilane-grafted nanoparticles.
[0035] Comparative Example 5 The difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is only that the preparation method of the carboxylsilane grafted nanoparticles in step (3) of the preparation method of the hydrolysis-resistant PC material in this comparative example is as follows: 1g of succinic anhydride-terminated polydimethylsiloxane (viscosity of 75~100cSt at 25℃) is added to 100mL of N,N-dimethylformamide and stirred evenly to obtain a succinic anhydride-terminated polydimethylsiloxane solution; 0.6g of amino nano-silica and 1.5g of amino nano-titanium dioxide are added to 180mL of N,N-dimethylformamide and ultrasonically dispersed evenly to obtain a nanoparticle dispersion, and then... The nanoparticle dispersion was poured into a three-necked flask and stirred at 600 rpm. After heating to 90°C, the succinic anhydride-terminated polydimethylsiloxane solution was added dropwise to the three-necked flask (the sum of the amino molar amounts of amino nano-silica and amino nano-titanium dioxide in the nanoparticle dispersion was equal to the anhydride molar amount of succinic anhydride-terminated polydimethylsiloxane). After the addition was completed, the reaction was stirred for 12 h. After cooling to room temperature, the mixture was centrifuged at 10,000 rpm for 10 min. The solid obtained by centrifugation was washed three times with N,N-dimethylformamide and ethanol, and then vacuum dried to constant weight to obtain carboxylsilane-grafted nanoparticles.
[0036] Comparative Example 6 The difference between the preparation method of the hydrolysis-resistant PC material in this comparative example and the preparation method of the hydrolysis-resistant PC material in Example 1 is that the modified nanoparticles in step (5) of the preparation method of the hydrolysis-resistant PC material in this comparative example are the carboxylsilane grafted nanoparticles prepared in step (3) of Example 1, that is, step (4) is omitted.
[0037] Experimental Example To evaluate the mechanical and hydrolysis resistance properties of the hydrolysis-resistant PC materials prepared in each embodiment and comparative example, the hydrolysis-resistant PC materials prepared in each embodiment and comparative example were dried in an oven at 120°C for 6 hours and then injection molded into standard specimens at an injection temperature of 260°C. The tensile strength and elongation at break of the specimens were then tested according to standard ISO 527, and the impact strength at room temperature and -40°C was tested according to standard ISO 180. Finally, the decrease rate of impact strength of the specimens after being placed in an environmental chamber at 90°C and 90% humidity for 72 hours was tested relative to the initial impact strength at 20°C. The test results are shown in Table 1.
[0038] Table 1 Mechanical properties and hydrolysis resistance of hydrolysis-resistant PC materials
[0039] According to the test results in Table 1, the hydrolysis-resistant PC material prepared by this invention has high tensile strength, elongation at break and high and low temperature impact strength, as well as high hydrolysis resistance, and has good application prospects.
[0040] As shown in Example 1 and Comparative Examples 1-3, when PC materials are modified using a mixture of nano-silica, nano-titanium dioxide, and glycidyl methacrylate-grafted polyethylene, although the glycidyl methacrylate-grafted polyethylene can improve the compatibility of nanoparticles in the system to some extent, its dispersion ability is still poor because the surface of the solid particles is not modified. When a mixture of amino-based nano-silica, amino-based nano-titanium dioxide, and glycidyl methacrylate-grafted polyethylene is used, although the surface of the nanoparticles is modified with polar amino groups, the dispersion of the modified nanoparticles is still poor due to the limited number of amino groups and the short length of the organic molecular chains. When a melt extrusion of amino-based nano-silica, amino-based nano-titanium dioxide, and glycidyl methacrylate-grafted polyethylene is used, the surface of the nanoparticles is grafted with polyethylene segments, which improves its dispersion ability, and thus the mechanical properties and hydrolysis resistance of the PC material are also improved to some extent.
[0041] As can be seen from Example 1 and Comparative Examples 4-5, when amino-based nano-silica, amino-based nano-titanium dioxide, and succinic anhydride-terminated polydimethylsiloxane are mixed and reacted simultaneously, the prepared modified nanoparticles have the greatest improvement on the mechanical properties and hydrolysis resistance of PC materials. This indicates that the two types of nanoparticles have a synergistic effect on improving the mechanical properties and hydrolysis resistance of PC materials.
[0042] As can be seen from Example 1 and Comparative Example 6, by omitting the step of chemically grafting polyethylene segments in step (4), the modified nanoparticles contain more hydrophilic carboxyl groups and lack polyethylene segments, resulting in a compatibility deviation between the modified nanoparticles and the polymer matrix. At the same time, the hydrophilic carboxyl groups reduce the hydrolysis resistance of the material.
Claims
1. A method for preparing a hydrolysis-resistant PC material, characterized in that, Includes the following steps: (1) Succinic anhydride-terminated polydimethylsiloxane, amino nano-silica, and amino nano-titanium dioxide are mixed and reacted in a solvent at 90-95°C to obtain carboxylsilane-grafted nanoparticles; the sum of the amino molar amounts of the amino nano-silica and amino nano-titanium dioxide is equal to the anhydride molar amount of the succinic anhydride-terminated polydimethylsiloxane; the mass ratio of the amino nano-silica to the amino nano-titanium dioxide is 0.6-0.8:1.2-1.5; (2) Modified nanoparticles were obtained by melt extrusion of carboxysilane-grafted nanoparticles and glycidyl methacrylate-grafted polyethylene. (3) Polycarbonate and modified nanoparticles are melt-extruded to obtain hydrolysis-resistant PC material.
2. The method for preparing the hydrolysis-resistant PC material as described in claim 1, characterized in that, The preparation method of the amino-based nano-silica is as follows: nano-silica, ethanol and water are mixed to obtain a dispersion. Concentrated ammonia and 3-aminopropyltrimethoxysilane are added to the dispersion and mixed and reacted at 75~80℃ for 10~12h to obtain amino-based nano-silica.
3. The method for preparing the hydrolysis-resistant PC material as described in claim 2, characterized in that, For every 2g of nano-silica, the corresponding volume of concentrated ammonia is 5~6mL, and the volume of 3-aminopropyltrimethoxysilane is 1~1.5mL.
4. The method for preparing the hydrolysis-resistant PC material as described in claim 1, characterized in that, The preparation method of the amino-based nano-titanium dioxide is as follows: nano-titanium dioxide, ethanol and water are mixed to obtain a dispersion. Concentrated ammonia and 3-aminopropyltrimethoxysilane are added to the dispersion and the mixture is reacted at 75~80℃ for 10~12h to obtain amino-based nano-titanium dioxide.
5. The method for preparing the hydrolysis-resistant PC material as described in claim 4, characterized in that, For every 2g of nano-titanium dioxide, the corresponding volume of concentrated ammonia is 5~6mL, and the corresponding volume of 3-aminopropyltrimethoxysilane is 1~1.5mL.
6. The method for preparing the hydrolysis-resistant PC material according to any one of claims 1-5, characterized in that, The viscosity of the succinic anhydride-terminated polydimethylsiloxane at 25°C is 75~100 cSt.
7. The method for preparing the hydrolysis-resistant PC material according to any one of claims 1-5, characterized in that, The mixing reaction in step (1) takes 12 to 15 hours.
8. The method for preparing the hydrolysis-resistant PC material as described in claim 1, characterized in that, The mass ratio of the carboxysilane-grafted nanoparticles to the glycidyl methacrylate-grafted polyethylene is 30~40:80~90; the melt index of the glycidyl methacrylate-grafted polyethylene at a temperature of 190℃ and a load of 2.16kg is 4.5~7.5g / 10min, and the grafting rate is 0.5~0.6%; the melt extrusion temperature in step (2) is 200~220℃.
9. The method for preparing the hydrolysis-resistant PC material as described in claim 1, characterized in that, The mass ratio of polycarbonate to modified nanoparticles is 100:20~30; the temperature of melt extrusion in step (3) is 250~260℃, and the melt flow rate of polycarbonate is 10~12g / min.
10. A hydrolysis-resistant PC material prepared by the method described in any one of claims 1-9.