CN115678098A - Simple preparation method of ultra-smooth surface formed by polyimide composite microspheres - Google Patents

Abstract

The invention belongs to the field of ultra-smooth surface materials, and relates to a simple preparation method of an ultra-smooth surface material of polyimide microspheres and a prepared ultra-smooth surface material. Firstly, D is catalyzed by tetramethyl ammonium hydroxide ₄ And 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane are subjected to ring-opening reaction to obtain APT-PDMS. And respectively reacting the prepared APT-PDMS with BAPP and HPMDA, and performing polycondensation by utilizing an amino terminal on the APT-PDMS and a carboxyl on the HPMDA to form the nano-sized polyamic acid microsphere. Preparing the final polymer into a base material, and performing thermal imineAfter the melting, the lubricating oil is filled in to obtain the ultra-smooth material consisting of the polyimide microspheres. After the base of the invention is oiled, the water drops can slide on the surface, and SA is 3 degrees. The super-smooth surface also has certain antifouling, antibacterial and self-cleaning performances.

Description

A Simple Preparation Method of Super-slippery Surface Composed of Polyimide Composite Microspheres

technical field

The invention belongs to the field of super-slippery surface materials, and in particular relates to a simple preparation method of polyimide microsphere super-slippery surface materials and the prepared super-slippery surface material.

Background technique

Since the concept of liquid-infused porous super-slippery surface was proposed in 2011, it has been widely used in antibacterial, anti-freezing, self-cleaning, fluid transmission and other fields. Because there is a stable and continuous lubricating oil layer on its surface, many droplets have low sliding resistance on its surface, making it difficult to infiltrate and adhere to the surface, endowing it with good sliding properties. However, under conditions such as external impact, high temperature and high pressure, the lubricating oil layer will be lost, and the substrate is easily damaged, so how to obtain a super-slip surface with good thermal stability and good durability is the technical problem to be solved by the present invention.

Contents of the invention

The purpose of the present invention is to provide a simple and easy preparation method for an ultra-slippery surface made of polyimide composite microspheres.

In order to realize the object of the present invention, the technical scheme adopted is:

A kind of simple preparation method of polyimide microsphere ultra-slip surface material, comprises the following steps:

(1) Preparation of APT-PDMS: octamethylcyclotetrasiloxane (D ₄ ) and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane Alkane monomer, with tetramethylammonium hydroxide ((Me) ₄ NOH) as catalyst, through ring-opening reaction to prepare amino-terminated polydimethylsiloxane (APT-PDMS), APT-PDMS structural formula is as follows:

Further, add an appropriate amount of _D4 and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane into a three-neck round bottom flask, and then add an appropriate amount of (Me) ₄ NOH is used as a catalyst for the ring-opening reaction. The reaction is carried out in a dry nitrogen environment. The reaction temperature is generally 105°C. After 18 hours of reaction, the reaction system is heated up to the catalyst degradation temperature, generally around 180°C, to degrade the catalyst. Then lower the temperature to about 160°C, remove low-boiling point small molecule impurities and other by-products, and obtain a colorless and viscous APT-PDMS liquid.

(2) Preparation of polyamic acid microspheres: use BAPP, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (HPMDA) and APT-PDMS as raw materials to prepare polyamic acid microspheres; further, APT - The molar ratio of PDMS, BAPP and HPMDA is 0.4:0.6:1.

Further, using DMAc as a solvent, at room temperature (generally 0-35°C), first add LP, Span85 and Tween80 into a three-neck round bottom flask and stir thoroughly (generally 30min), then add solvent DMAc and continue stirring for 1h±30min , and then pass nitrogen gas for 5±10min and weigh APT-PDMS and BAPP with a set molar ratio for full reaction (reaction time is preferably 2h±30min). Finally, add the weighed HPMDA (under _N2 atmosphere) three times, fully react under the condition of ice bath (generally about 6h), and then dry (the drying condition is preferably at 90°C for at least 12h).

(3) Preparation of super slippery surface: disperse polyamic acid microspheres in toluene, control the concentration at 20-30 mg/mL, drop-coat on glass sheet to prepare substrate, and carry out thermal imidization reaction after drying to obtain polyimide The porous substrate composed of amine microspheres was poured into simethicone oil, and stood vertically for at least 12 hours, and finally an ultra-smooth surface was obtained.

Further, the glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use, and then the polyamic acid dispersion was drop-coated in an oven at 100 ° C. On the cleaned glass substrate, the thermal imidization condition is to calcinate at 300±20°C for at least 1h.

Compared with prior art, the beneficial effect of the present invention is:

The invention uses APT-PDMS, BAPP and HPMDA as raw materials, and prepares a unique super-smooth surface of polyimide microspheres through a breath diagram method, and the super-smooth surface is composed of nanometer-level polyimide microspheres. In addition, the surface morphology of the substrate can be controlled by changing the molecular weight of APT-PDMS, the molar ratio of APT-PDMS and BAPP, and the polymer concentration during drop coating.

Description of drawings

Fig. 1 is APT-PDMS reaction formula in embodiment 1 step (1);

Fig. 2 is the reaction formula of synthesizing polyamic acid and polyimide in embodiment 1 step (2) and step (3);

Fig. 3 is the infrared spectrogram of polyimide;

Fig. 4 is the sliding angle diagram after the porous surface oiling that is obtained by the combination of polyimide microspheres in step (3) of embodiment 1;

Fig. 5 is the scanning electron micrograph of the porous substrate obtained by the combination of polyimide microspheres;

Fig. 6 is the thermal gravimetric diagram of polyimide;

Fig. 7 is a schematic diagram of the sliding angle of porous substrates prepared with different molar ratios.

Detailed ways

The present invention is not limited to the following specific embodiments. Those skilled in the art can implement the present invention in various other specific embodiments according to the disclosed content of the present invention, or make simple changes or All changes fall within the protection scope of the present invention. It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

The present invention is described in further detail below in conjunction with embodiment:

Example 1:

(1) Preparation of APT-PDMS (Mn=3505)

Weigh 29.7g of _D4 and 2.5g of 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane respectively, and add them to a three-neck round bottom flask, Then weigh 0.6g of (Me) ₄ NOH, (Me) ₄ NOH is used as a catalyst under the reaction condition of 105 ° C to carry out ring opening under the atmosphere of dry N ₂ , after 18 hours of reaction, the temperature is raised to 180 ° C to degrade the catalyst, and then Lower the temperature to 160°C to remove low-boiling point small molecule impurities and other by-products, and obtain a colorless viscous APT-PDMS liquid.

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.5:0.5);

First weigh 8g of liquid paraffin LP, 1.73g of Span85 and 0.43g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc and continue to stir for 1h, then weigh 1.75g of APT-PDMS and 0.21g of Tween80 respectively. The BAPP was continuously stirred for 2h in a dry _N2 atmosphere, then 0.23g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir for 6h in a dry _N2 atmosphere and an ice bath. After centrifuging three times, the bottom layer was dried in a vacuum oven at 80°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30 mg of the polyamic acid prepared in step (2) and dissolve it in toluene. After it is fully dissolved by ultrasound, after fully dissolving, apply the solution onto a clean glass substrate in an oven at 100° C. and dry it. After calcination in a muffle furnace at 300°C for 1 hour, pour simethicone, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

Figure 1 is the reaction formula for the synthesis of APT-PDMS.

Figure 2 is a reaction formula for synthesizing polyimide.

Figure 3 a is the infrared spectrum of the prepared APT-PDMS. In the infrared spectrum of APT-PDMS, at 3407cm ^-1 is the characteristic absorption peak of NH ₂ , at 2908cm ^-1 and 2967cm ^-1 are the stretching vibration absorption peaks of Si- _CH3 , at 1024cm ^-1 and 1093cm ^-1 are The stretching vibration peak of the main chain Si-O. The appearance of the above characteristic peaks all indicated that APT-PDMS was synthesized successfully.

b in Figure 3 is the infrared spectrum of the finally synthesized polyimide microspheres. The C=O 1700cm ^-1 in the CO-NH characteristic absorption band of polyimide appears obviously, and the 1741cm ^-1 and 1715cm ^-1 are the asymmetric vibration and symmetric stretching vibration of C=O in the imide ring respectively, At 804 cm ^-1 is the bending vibration of C=O, and at 1352 cm ^-1 the stretching vibration of CN in the imide ring is observed. 2928cm ^–1 and 2958cm ^–1 are the stretching vibration absorption peaks of the methyl group attached to the silicon atom respectively, and 1096cm ^–1 and 1018cm ^–1 are the stretching vibration characteristic peaks of Si-O. polyimide of polysiloxane.

The sliding angle of the SLIPS prepared in Example 1 is 3°.

Example 2

(1) APT-PDMS preparation method is the same as embodiment 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.4:0.6);

First weigh 8g of LP, 1.72g of Span85 and 0.43g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 1.40g of APT-PDMS and 0.25g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 80°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30mg of the polymer and dissolve it in the mixed solution of toluene and chloroform and the toluene solution respectively. After it is fully dissolved by ultrasound, after fully dissolving, apply the solution drop-coated on a clean glass substrate in an oven at 100°C and dry it. After calcination in a muffle furnace at 300°C for 1 hour, simethicone was poured in, and the glass sheet was placed vertically overnight (at least 12 hours) so that the excess oil on the surface was lost under the action of gravity to obtain SLIPS.

The sliding angle of the SLIPS prepared in Example 2 is 3°.

Figure 4 is the sliding angle.

Figure 5 is a SEM image.

Example 3

(1) The method for preparing APT-PDMS is the same as in Example 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.6:0.4);

First weigh 8g of LP, 1.73g of Span85 and 0.44g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 2.10g of APT-PDMS and 0.16g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 100°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30 mg of polymer and dissolve it in toluene. After being fully dissolved by ultrasound, apply the solution dropwise on a clean glass substrate in an oven at 100°C and dry it, and then calcinate in a muffle furnace at 300°C for 1 hour. Pour in simethicone oil, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

The sliding angle of the SLIPS prepared in Example 3 is 3°.

Example 4

(1) The method for preparing APT-PDMS is the same as in Example 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.5:0.5);

First weigh 8g of LP, 1.73g of Span85 and 0.43g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 1.75g of APT-PDMS and 0.21g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 100°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30 mg of polymer and dissolve in toluene or chloroform. After being fully dispersed by ultrasound, after fully dissolving, apply the solution dropwise on a clean glass substrate in an oven at 100°C and dry it. After calcination at ℃ for 1 hour, pour in simethicone oil, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

The sliding angle of the SLIPS prepared in Example 4 is 3°.

Comparative example 1

(1) The method for preparing APT-PDMS is the same as in Example 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.8:0.2);

First weigh 8g of LP, 1.73g of Span85 and 0.43g of Tween80 and react in a three-necked round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 2.79g of APT-PDMS and 0.09g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 85°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30 mg of the polymer and dissolve it in a mixed solution of toluene, chloroform and toluene. After it is fully dissolved by ultrasound, apply the solution dropwise on a clean glass substrate in an oven at 100°C and dry it. After being calcined in a muffle furnace at 300°C for 1 hour, simethicone was poured into it, and the glass sheet was placed vertically overnight (at least 12 hours) so that the excess oil on the surface would be lost under the action of gravity to obtain SLIPS.

The sliding angle of the SLIPS prepared in Example 5 is 11°.

Comparative example 2

(1) APT-PDMS preparation method is the same as embodiment 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.7:0.3);

First weigh 8g of LP, 1.73g of Span85 and 0.43g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 2.45g of APT-PDMS and 0.12g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 80°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30mg of polymer and dissolve in toluene or chloroform. After fully dissolved by ultrasound, after fully dissolved, apply the solution dropwise on a clean glass substrate in an oven at 100°C and dry it. After calcination at ℃ for 1 hour, pour in simethicone oil, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

The sliding angle of the SLIPS prepared in Comparative Example 1 was 13°.

Comparative example 3

(1) APT-PDMS preparation method is the same as embodiment 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.3:0.7);

First weigh 8g of LP, 1.73g of Span85 and 0.43g of Tween80 and react in a three-neck round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 3.1g of APT-PDMS and 0.04g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere and an ice bath for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 80°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30mg of polymer and dissolve in toluene or chloroform. After fully dissolved by ultrasound, after fully dissolved, apply the solution dropwise on a clean glass substrate in an oven at 100°C and dry it. After calcination at ℃ for 1 hour, pour in simethicone oil, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

The SLIPS prepared in Comparative Example 2 did not slide.

Comparative example 4

(1) APT-PDMS preparation method is the same as embodiment 1;

(2) Preparation of polyamic acid microspheres (the molar ratio of APT-PDMS to BAPP is 0.5:0.5);

First weigh 14g of LP, 1.76g of Span85 and 0.47g of Tween80 and react in a three-necked round bottom flask for 30min, then add 2.5g of DMAc to continue the reaction for 1h, and weigh 1.75g of APT-PDMS and 0.21g of BAPP Stirring was continued for 2 h in a dry N ₂ atmosphere, then 0.23 g of HPMDA was weighed and added into a three-necked flask three times, and the reaction was terminated after continuing to stir in a dry N ₂ atmosphere for 6 h. After centrifuging three times, the bottom layer was dried in a vacuum oven at 80°C.

(3) Preparation of super slippery surface

The glass substrate was placed in an ultrasonic bath, washed three times with ethanol and acetone solutions, and then dried with a blower for later use. Weigh 30 mg of polymer and dissolve in toluene and chloroform. After being fully dissolved by ultrasound, the solution is drip-coated on a clean glass substrate in an oven at 100°C and dried. After calcination at ℃ for 1 hour, pour in simethicone oil, and place the glass sheet vertically overnight (at least 12 hours) so that the excess oil on the surface will be lost under the action of gravity to obtain SLIPS.

The SLIPS prepared in Comparative Example 3 did not slide.

Based on the verification of the above examples and comparative examples, the present invention uses BAPP, APT-PDMS and HPMDA as raw materials, adjusts the reaction conditions, and prepares a porous substrate structure composed of polyimide microspheres. The balls are small balls of nanometer level. The structure has a sliding angle of 3° after oil filling, and has good thermal stability, durability, antifouling, self-cleaning and other properties.

The contact angles of porous substrates with different ratios of BAPP and APT-PDMS were compared, as shown in Table 1. Among them, the substrate with a ratio of 0.4:0.6 has the best sliding performance.

Table 1 shows the static contact angle and sliding angle of porous substrates with different ratios of BAPP and APT-PDMS before and after oil filling

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto, any person familiar with the technical field within the technical scope disclosed in the present invention, according to the technical solution of the present invention Equivalent replacements or changes to the concepts thereof shall fall within the protection scope of the present invention.

Claims (9)

1. A simple preparation method of a polyimide microsphere ultra-smooth surface material is characterized by comprising the following steps:

(1) Preparation of APT-PDMS: with octamethylcyclotetrasiloxane (D) ₄ ) And 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane monomer with tetramethylammonium hydroxide ((Me) ₄ NOH) as a catalyst, and performing ring-opening reaction to obtain amino-terminated polydimethylsiloxane (APT-PDMS), wherein the APT-PDMS has the following structural formula:

(2) Preparation of polyamide acid microspheres: preparing polyamide acid microspheres by using BAPP, 1,2,4,5-cyclohexane tetracarboxylic dianhydride (HPMDA) and APT-PDMS as raw materials; .

(3) Preparation of ultra-smooth surface: dispersing polyamide acid microspheres in toluene, controlling the concentration to be 20-30 mg/mL, dripping on a glass sheet to prepare a substrate, drying, performing thermal imidization reaction to obtain a porous substrate consisting of the polyimide microspheres, pouring dimethyl silicone oil, and vertically standing for at least 12 hours to finally obtain the super-smooth surface. .

2. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 1, which is characterized in that: the step (1) comprises the following specific steps: adding an appropriate amount of D ₄ And 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane was charged to a three-necked flask, followed by the addition of an appropriate amount of (Me) ₄ And (2) carrying out ring-opening reaction by using NOH as a catalyst, carrying out the reaction in a dry nitrogen environment, after the reaction is finished, heating a reaction system to the degradation temperature of the catalyst to degrade the catalyst, and cooling to remove low-boiling-point micromolecular impurities and other byproducts to obtain colorless and viscous APT-PDMS liquid.

3. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 2, characterized in that: the ring-opening reaction temperature in the step (1) is 105 ℃, the reaction time is 18h, and the degradation temperature of the catalyst is 180 ℃.

4. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 1, wherein the molar ratio of APT-PDMS, BAPP and HPMDA in the step (2) is 0.4.

5. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 1, which is characterized in that: the specific steps of the step (2) comprise: using DMAc as a solvent, firstly adding LP, span85 and Tween80 into a three-neck round-bottom flask at room temperature, fully stirring, then adding the solvent DMAc, continuously stirring for 1h +/-30 min, introducing nitrogen for 5 +/-10 min, and weighing APT-PDMS and BAPP with a set molar ratio for fully reacting; finally in N ₂ Adding weighed HPMDA in three times under the atmosphere in an ice bathAnd then dried.

6. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 5, which is characterized in that: in the step (2), the reaction temperature is 30 ℃, the reaction time of APT-PDMS and BAPP is 2h +/-30 min, and the reaction time after adding HPMDA is 6h.

7. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 5, which is characterized in that: the drying conditions in the step (2) are as follows: vacuum drying at 90 deg.C for 12h.

8. The simple preparation method of the polyimide microsphere ultra-smooth surface material according to claim 1, which is characterized in that: the specific steps of the step (3) comprise: placing the glass substrate in an ultrasonic bath, respectively washing with ethanol and acetone solution for 3 times, drying for later use, dripping the polyamic acid dispersion liquid on the cleaned glass substrate in an oven at 100 ℃, and calcining for at least 1h under the condition of thermal imidization at 300 +/-20 ℃.

9. The polyimide microsphere ultra-smooth surface material prepared by the simple preparation method of the polyimide microsphere ultra-smooth surface material according to any one of claims 1 to 8.

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