Surface silicon oxidation polyimide-co-silane thin film and preparation method thereof

[0027] Example 1

[0028] (1) Dissolve 2.94g 3,3,4',4'-bipyromellitic dianhydride in 55.86g N,N-dimethylformamide (DMF) under the protection of nitrogen at room temperature. The solid content is 5%, stir for 5 hours to obtain 3,3,4',4'-bipyromellitic dianhydride solution;

[0029] (2) Under the protection of nitrogen, dissolve 0.78g of diaminopolysiloxane with a molecular weight of 860 in 14.82g of tetrahydrofuran, with a solid content of 5%, and stir for 5 hours to obtain a diaminopolysiloxane tetrahydrofuran solution;

[0030] (3) The diaminopolysiloxane tetrahydrofuran solution was slowly added dropwise to the 3,3,4',4'-bipyromellitic dianhydride solution, and after stirring for 6 hours, 1.82g 4,4 '-Diaminodiphenyl ether and 34.58g N,N-dimethylformamide (DMF), stirred for 4 hours to obtain oligomeric polyamic acid siloxane solution 1;

[0031] (4) Transfer the oligomeric polyamic acid-co-siloxane solution 1 into an autoclave, replace the air with nitrogen, pressurize it to 0.14 MPa, keep it at 40°C for 1 hour and 80°C for 1 hour, Cool to room temperature to obtain viscous polyamic acid-co-siloxane solution 1;

[0032] (5) The polyamic acid-co-siloxane solution 1 is temperature-programmed as follows: 40°C, 4 hours; 60°C, 4 hours; 80°C, 1 hour; 100°C, 1 hour; 120°C, 2 Hours; 200°C, 1 hour; 250°C, 1 hour; 300°C, 0.5 hours; After cooling to room temperature, soak in deionized water, wash with ethanol, and dry to obtain polyimide-co-siloxane film 1 ;

[0033] (6) Use ground atomic oxygen equipment to irradiate the surface of polyimide-co-siloxane film 1 to obtain surface silicon-oxidized polyimide-co-siloxane film 1; the irradiation conditions are: temperature 253K , Energy 4.5eV, cumulative flux is 1.33×10 20 atoms/cm 2.

[0034] figure 1 It is a cross-sectional view of surface silicon oxidized polyimide-co-siloxane film 1; figure 2 Is the differential scanning calorimetry (DSC) chart of the surface silicon-oxidized polyimide-co-siloxane film 1 in Example 1; image 3 X-ray electron spectroscopy (XPS) image of surface silicon-oxidized polyimide-co-siloxane film 1; Figure 4 It is a scanning electron microscope (SEM) photo of the surface silicon oxide polyimide-co-siloxane film 1; Figure 5 It is the change trend graph of Si content of surface silicon-oxidized polyimide-co-siloxane film 1; Table 1 is polyimide-co-siloxane film 1 and surface silicon-oxidized polyimidesiloxane film 1 Si XPS spectrum quantitative analysis results. by figure 1 It can be seen that the surface silicon oxide polyimide-co-siloxane film 1 is composed of a glass layer, a transition layer and a base layer. The glass layer is mainly composed of a silicon-oxygen structure composed of a glass-like structure, the transition layer is composed of a silicon-oxygen structure and a polyimide-co-siloxane structure; the base layer is composed of a polyimide-co-siloxane structure. The glass layer acts as a functional layer to resist atomic oxygen erosion; the transition layer connects the glass layer and the base layer; the base layer plays the role of supporting the glass layer and the transition layer. by figure 2 It can be seen that the glass transition temperature of the polyimide-co-siloxane 1 prepared in Example 1 is 245°C, and it has good heat resistance; image 3 It can be seen that the peak value of XPS is 103.3eV, which is Si 4+ The characteristic peaks indicate that SiO is formed on the irradiated surface of atomic oxygen x;by Figure 4 It can be seen that the surface of the silicon-oxidized polyimide-co-siloxane film 1 prepared in Example 1 is smooth and has no obvious defects. As can be seen from Table 1, polyamide

[0035] Table 1 Quantitative analysis results of Si XPS spectra of polyimide-co-siloxane film 1 and surface silicon-oxidized polyimide-co-siloxane film 1

[0036]

[0037] The quantitative analysis results of the Si XPS spectrum of the imine-co-siloxane film 1 and the surface silicon oxide polyimide-co-siloxane film 1 show that the treatment of atomic oxygen causes the methylsiloxane on the surface of the material to change to SiO x Conversion, the conversion percentage is as high as 99%. Figure 5 It can be seen that the silicon oxide layer on the surface of the material is about 100nm, and as the depth of the film changes, SiO x The content of silicon in the battery shows a downward trend. By weighing the mass change before and after the atomic oxygen treatment, it can be seen that the outgassing volume of the material in Example 1 is 0.078mg/cm 2.

[0038] Example 2

[0039] (1) Dissolve 2.94g 3,3,4',4'-bipyromellitic dianhydride in 14.70g N,N-dimethylacetamide (DMAc) under the protection of nitrogen at room temperature. The solid content is 20%, stirring under nitrogen for 3 hours to obtain 3,3,4',4'-bipyromellitic dianhydride solution;

[0040] (2) Under the protection of nitrogen, dissolve 21 g of diaminopolysiloxane with a molecular weight of 2100 in 84 g of tetrahydrofuran, with a solid content of 20%, and stir under nitrogen for 3 hours to obtain a diaminopolysiloxane tetrahydrofuran solution;

[0041] (3) Slowly adding the diaminopolysiloxane tetrahydrofuran solution dropwise to the aromatic tetraacid dianhydride solution to obtain the oligomeric polyamic acid-co-siloxane solution 2;

[0042] (4) Transfer the oligomeric polyamic acid-co-siloxane solution 2 to an autoclave, replace the air with nitrogen, pressurize it to 0.14 MPa, keep it at 60°C for 3 hours and 100°C for 3 hours, Cool to room temperature to obtain viscous polyamic acid-co-siloxane solution 2;

[0043] (5) The polyamic acid-co-siloxane solution 2 is temperature-programmed as follows: 40°C, 8 hours; 60°C, 8 hours; 80°C, 3 hours; 100°C, 3 hours; 120°C, 4 Hours; 200°C, 2 hours; 250°C, 2 hours; 300°C, 1 hour. After cooling down to room temperature, soak in deionized water and wash with acetone to obtain polyimide-co-siloxane film 2;

[0044] (6) Use ground atomic oxygen equipment to irradiate the surface of the polyimide-co-siloxane film 2 to obtain the surface silicon-oxidized polyimide-co-siloxane film 2; the irradiation conditions are: temperature 353K ; Energy 1.1eV; Cumulative flux 1×10 21 atoms/cm 2.

[0045] The characterization result of the surface silicon-oxidized polyimide-co-siloxane film 2 is similar to that of the surface silicon-oxidized polyimide-co-siloxane film 1.

[0046] Example 3

[0047] (1) At room temperature and under the protection of nitrogen, 2.18g pyromellitic dianhydride was dissolved in 19.08g N-methylpyrrolidone (NMP) with a solid content of 10%. Stir under nitrogen for 4h to obtain a pyromellitic dianhydride solution ;

[0048] (2) Under the protection of nitrogen, dissolve 1.48g of diaminopolysiloxane with a molecular weight of 950 in 13.32g of tetrahydrofuran, with a solid content of 10%, and stir under nitrogen for 4 hours to obtain a diaminopolysiloxane tetrahydrofuran solution ;

[0049] (3) The diaminopolysiloxane tetrahydrofuran solution was slowly added dropwise to the aromatic tetraacid dianhydride solution, and after stirring for 4 hours, 3.46g of 2,2-bis[4-(4-aminobenzene) was added. (Oxy)phenyl]propane and 31.14g of N-methylpyrrolidone (NMP), stirred for 4 hours to obtain oligomeric polyamic acid-co-siloxane solution 3;

[0050] (4) Transfer the oligomeric polyamic acid-co-siloxane solution 3 to an autoclave, replace the air with nitrogen, pressurize it to 0.14 MPa, keep it at 60°C for 3 hours and 100°C for 3 hours, Cool to room temperature to obtain viscous polyamic acid-co-siloxane solution 3;

[0051] (5) The polyamic acid-co-siloxane solution 3 is temperature-programmed as follows: 40°C, 6 hours; 60°C, 6 hours; 80°C, 2 hours; 100°C, 2 hours; 120°C, 3 Hours; 200°C, 1.5 hours; 250°C, 1.5 hours; 300°C, 0.75 hours; after cooling to room temperature, soak in deionized water, wash with ethanol, and dry to obtain polyimide-co-siloxane film 3 ;

[0052] (6) Use ground atomic oxygen equipment to irradiate the surface of the polyimide-co-siloxane film 3 to obtain the surface silicon-oxidized polyimide-co-siloxane film 3; the irradiation conditions are: temperature 283K ; Energy 3.5eV; Cumulative flux 5×10 20 atoms/cm 2.

[0053] The characterization result of the surface silicon-oxidized polyimide-co-siloxane film 3 is similar to that of the surface silicon-oxidized polyimide-co-siloxane film 1.