阅读说明：本技术 一种高分子压力敏感漆及其制备方法和应用 (High-molecular pressure sensitive paint and preparation method and application thereof ) 是由 田颜清 史佳艳 于 2021-01-20 设计创作，主要内容包括：本发明提供一种高分子压力敏感漆及其制备方法和应用,所述高分子压力敏感漆具有式I所示结构,本发明的高分子压力敏感漆由聚二甲基硅氧烷、甲基丙烯酸异丁酯以及可聚合的四苯基卟啉铂构成,合成过程简单,可控。该聚合物可以应用在压力范围为10-190kPa的测试中,响应速度快,灵敏度可以达到0.82％/kPa,灵敏度高,可以应用于各类飞行器表面及其各个零部件负载分析中,具有广阔的应用前景。(The invention provides a high-molecular pressure-sensitive paint, a preparation method and an application thereof, wherein the high-molecular pressure-sensitive paint has a structure shown in a formula I, is composed of polydimethylsiloxane, isobutyl methacrylate and polymerizable tetraphenylporphyrin platinum, and is simple and controllable in synthesis process. The polymer can be applied to the test with the pressure range of 10-190kPa, has high response speed, high sensitivity of 0.82%/kPa and wide application prospect, and can be applied to the load analysis of the surfaces of various aircrafts and various parts thereof.)

1. A high-molecular pressure-sensitive paint is characterized by having the following structure:

wherein n is an integer of 1 to 200, m is an integer of 1 to 5000, and x is an integer of 1 to 100.

2. The method for preparing a high molecular pressure-sensitive paint according to claim 1, wherein the method comprises the following steps:

(1) reacting monohydroxy polydimethylsiloxane with 2-bromine isobutyryl bromide to obtain a polydimethylsiloxane initiator;

(2) and (3) initiating tetraphenylporphyrin platinum containing methacrylic acid groups and isobutyl methacrylate to carry out polymerization reaction by utilizing a polydimethylsiloxane initiator in the presence of a catalyst to obtain the high-molecular pressure-sensitive paint.

3. The preparation method according to claim 2, wherein the molar ratio of the monohydroxypolydimethylsiloxane to the 2-bromoisobutyryl bromide in the step (1) is 1:1 to 1: 10.

4. The production method according to claim 2 or 3, characterized in that the reaction of step (1) is carried out in the presence of a basic substance, preferably any one or a combination of at least two of triethylamine, pyridine or diethylisopropylamine;

preferably, the solvent for the reaction of step (1) is tetrahydrofuran and/or dichloromethane.

5. The method according to any one of claims 2 to 4, wherein the temperature of the reaction of step (1) is room temperature to 40 ℃;

preferably, the reaction time in the step (1) is 16-72 hours.

6. The method according to any one of claims 2 to 5, wherein the molar ratio of the polydimethylsiloxane initiator of step (2) to the platinum tetraphenylporphyrin containing methacrylic acid groups is from 20:1 to 5000: 1;

preferably, the mole ratio of the platinum tetraphenylporphyrin containing methacrylic acid groups to isobutyl methacrylate in step (2) is 1:20 to 1: 5000.

7. The production method according to any one of claims 2 to 6, wherein the catalyst of step (2) is cuprous bromide and/or cuprous chloride;

preferably, the molar ratio of the catalyst to the polydimethylsiloxane initiator in step (2) is 2:1-5: 1.

8. the production method according to any one of claims 2 to 7, wherein the polymerization reaction in step (2) is carried out in the presence of 1,1,4,7,10, 10-hexamethyltriethylene tetramine;

preferably, the molar ratio of the 1,1,4,7,10, 10-hexamethyl triethylene tetramine to the polydimethylsiloxane initiator is 2:1-5: 1.

9. The method according to any one of claims 2 to 8, wherein the reaction temperature in the step (2) is 80 ℃;

preferably, the reaction time of step (2) is 24 hours.

10. Use of a polymeric pressure sensitive paint according to claim 1 in a surface pressure test;

preferably, the surface pressure test is an aircraft surface pressure test or an aircraft part load analysis.

Technical Field

The invention belongs to the technical field of pressure-sensitive materials, and relates to a high-molecular pressure-sensitive paint, and a preparation method and application thereof.

Background

The surface pressure test is important in aerodynamic tests, and is generally applied to load analysis of aircrafts and various parts thereof and research of special fluid mechanics phenomenon. In the traditional surface pressure test, pressure holes are required to be formed in the surface of a tested model, and pressure sensors are arranged in an array mode to carry out measurement so as to obtain the surface pressure of the tested model. The method is simple and easy to operate and high in measurement accuracy, but the preparation process of the method is quite complex, the test period is long, the test cost is high, the obtained pressure information is not continuously distributed and is influenced by factors such as a model structure and the like, so that the traditional surface pressure test method has certain limitations. There is therefore a need for a non-contact, non-invasive measurement technique.

In the 80's of the 20 th century, Peterson et al proposed a new technique for testing the surface pressure of a model based on the principle of "oxygen quenching". This technique is known as the pressure sensitive paint test technique and has been widely used in aerodynamic testing. The pressure sensitive paint is a polymer containing oxygen probe molecules, and the working principle of the pressure sensitive paint is the principle of oxygen quenching. At room temperature, almost all molecules are in a ground state energy level, and when the oxygen probe molecules are irradiated by a light source with a certain wavelength, the oxygen probe molecules absorb energy to transition from the ground state to an excited state. The excited state is an unstable state, however, and the oxygen probe molecules are inactivated by radiation and non-radiation and returned to the ground state. During the radiation deactivation process, the oxygen probe molecules release energy back to the ground state in a luminescent manner (generating photons). In the process of non-radiative inactivation, oxygen probe molecules in an excited state collide with oxygen molecules in a ground state, and the oxygen molecules absorb the energy of the oxygen probe molecules and jump to the excited state, so that no photon is generated in the process of returning the oxygen probe molecules to the ground state. The oxygen molecules reduce the light intensity of the oxygen probe molecules in this process, and are therefore referred to as the "oxygen quenching" principle. And obtaining the pressure distribution on the surface of the measured model according to the change of the luminous intensity caused by the response of the oxygen probe molecules to the oxygen. The relation curve of the air pressure and the luminous intensity of the oxygen probe molecules is accurately measured in advance, and the pressure at a certain position on the surface of the measured model can be obtained according to the luminous intensity at the certain position.

The pressure sensitive lacquer polymers used in the prior art are mainly linear polymers, since suitable monomer units can improve the solubility of the polymers and even increase the stiffness of the polymers without significantly affecting the performance of the pressure sensitive lacquer. But the linear high molecular pressure sensitive paint has lower pressure sensitivity and poorer mechanical property.

Therefore, in the art, it is desired to develop a high molecular pressure sensitive paint capable of improving pressure sensitivity and having better mechanical properties.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a high-molecular pressure-sensitive paint, and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the present invention provides a high molecular pressure sensitive paint, which has a structure represented by formula I below:

wherein n is an integer of 1 to 200, m is an integer of 1 to 5000, and x is an integer of 1 to 100.

In the present invention, n may be 1, 3, 5, 8, 10, 15, 20, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180 or 200, m may be 1, 3, 5, 8, 10, 20, 50, 80, 100, 300, 500, 700, 1000, 2000, 3000, 4000 or 5000, etc., and x may be 1, 3, 5, 8, 10, 15, 20, 30, 40, 50, 60, 80 or 100, etc., for example, n is 79, m is 45, and x is 1; n is 79, m is 147, x is 1; or n is 79, m is 244 and x is 2.

The invention relates to a high-molecular pressure sensitive paint with a block structure, which selects polydimethylsiloxane as a chain segment of a block polymer to improve the oxygen permeability of the block polymer, selects isobutyl methacrylate as a monomer to improve the mechanical property of a material, and selects a polymerizable oxygen probe to improve the uniformity of probe molecules in the polymer. The high-molecular pressure sensitive paint has the characteristics of high pressure sensitivity, high response speed and the like.

In another aspect, the present invention provides a method for preparing a high molecular pressure sensitive paint as described above, comprising the steps of:

(1) reacting monohydroxy polydimethylsiloxane with 2-bromine isobutyryl bromide to obtain a polydimethylsiloxane initiator;

(2) and (3) initiating tetraphenylporphyrin platinum containing methacrylic acid groups and isobutyl methacrylate to carry out polymerization reaction by utilizing a polydimethylsiloxane initiator in the presence of a catalyst to obtain the high-molecular pressure-sensitive paint.

The block structure high molecular pressure sensitive paint is prepared by atom transfer radical polymerization of Polydimethylsiloxane (PDMS), isobutyl methacrylate (IBM) and polymerizable tetraphenylporphyrin platinum (OS) modified by hydroxyethyl methacrylate.

Preferably, the molar ratio of the monohydroxypolydimethylsiloxane to the 2-bromoisobutyryl bromide in step (1) is 1:1 to 1:10, such as 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1: 10.

Preferably, the reaction of step (1) is carried out in the presence of a basic substance, preferably any one or a combination of at least two of triethylamine, pyridine or diethylisopropylamine.

Preferably, the solvent for the reaction of step (1) is tetrahydrofuran and/or dichloromethane.

Preferably, the temperature of the reaction in step (1) is from room temperature to 40 ℃, such as 20 ℃, 25 ℃, 30 ℃, 35 ℃, 38 ℃ or 40 ℃,

preferably, the reaction time in step (1) is 16 to 72 hours, such as 16 hours, 18 hours, 20 hours, 23 hours, 25 hours, 28 hours, 30 hours, 35 hours, 40 hours, 48 hours, 50 hours, 55 hours, 60 hours, 64 hours, 66 hours, 68 hours, 70 hours or 72 hours.

Preferably, the molar ratio of the polydimethylsiloxane initiator to the platinum tetraphenylporphyrin containing methacrylic groups in step (2) is from 20:1 to 5000:1, such as 20:1, 30:1, 50:1, 80:1, 100:1, 300:1, 500:1, 800:1, 1000:1, 2000:1, 3000:1, 4000:1 or 5000:1, and the like.

Preferably, the molar ratio of the platinum tetraphenylporphyrin containing methacrylic groups to isobutyl methacrylate in step (2) is 1:20 to 1:5000, such as 1:20, 1:45, 1:147, 2:244, 1:200, 1:500, 1:800, 1:1000, 1:2000, 1:3000, 1:4000 or 1:5000 and the like.

Preferably, the catalyst in the step (2) is cuprous bromide and/or cuprous chloride.

Preferably, the molar ratio of catalyst used in step (2) to polydimethylsiloxane initiator is from 2:1 to 5:1, such as 2:1, 2.5:1, 2.8:1, 3:1, 3.5:1, 3.8:1, 4:1, 4.5:1, 4.8:1 or 5: 1.

Preferably, the polymerization reaction in the step (2) is carried out in the presence of 1,1,4,7,10, 10-hexamethyltriethylene tetramine. The 1,1,4,7,10, 10-hexamethyl triethylene tetramine has the functions of complexing copper ions and stabilizing the redox reaction of the copper ions.

Preferably, the molar ratio of the 1,1,4,7,10, 10-hexamethyltriethylenetetramine to polydimethylsiloxane initiator is from 2:1 to 5:1, such as 2:1, 2.5:1, 2.8:1, 3:1, 3.5:1, 3.8:1, 4:1, 4.5:1, 4.8:1 or 5: 1.

Preferably, the reaction temperature of step (2) is 80 ℃;

preferably, the reaction time of step (2) is 24 hours;

preferably, the reaction of step (2) is carried out in the absence of oxygen.

In another aspect, the present invention provides the use of a polymeric pressure sensitive paint as described above in a surface pressure test.

Preferably, the high molecular pressure sensitive paint is used for aircraft surface pressure testing or aircraft part load analysis.

Compared with the prior art, the invention has the following beneficial effects:

the high-molecular pressure sensitive paint consists of polydimethylsiloxane, isobutyl methacrylate and polymerizable tetraphenylporphyrin platinum, and has simple and controllable synthesis process. The polymer can be applied to the test with the pressure range of 10-190kPa, has high response speed, high sensitivity of 0.82%/kPa and wide application prospect, and can be applied to the load analysis of the surfaces of various aircrafts and various parts thereof.

Drawings

FIG. 1 is a schematic structural diagram of a pressure sensing performance testing instrument;

FIG. 2 is a graph of the results of a pressure test of polymer P1 at 20 ℃;

FIG. 3 is a graph of the results of a linear fit of Iref/I at different pressures at 20 ℃ for each polymer sample plate;

FIG. 4 is a graph of the results of pressure testing of a sample plate of Polymer P1 at various temperature times;

FIG. 5 is a graph of the luminous intensity of a sample plate of Polymer P1 fitted to the pressure at different temperatures and different pressures.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

In this example, a high molecular pressure sensitive paint was prepared by the following preparation method, the flow of which is shown below:

the method specifically comprises the following steps:

(1) synthesis of polydimethylsiloxane initiator:

2.335g (0.5mmoL) monohydroxypolydimethylsiloxane (n ═ 79) were dissolved in 30mL of Tetrahydrofuran (THF), and 0.506g (5mmoL) triethylamine (Et) was added₃N), 1.150g (5mmoL) of 2-bromoisobutyryl bromide was added dropwise via an isobaric dropping funnel, and stirred for 72 hours in ice bath. After the reaction is finished, the product is filtered, the filtrate is dried by spinning, and is dissolved in dichloromethane and extracted by pure water for multiple times. An appropriate amount of anhydrous magnesium sulfate was then added to the organic phase, filtered after 2h, and the resulting solution was rotary evaporated to give 1.657g of product in 68% yield.¹H-NMR(400MHz,CDCl₃,(ppm)):0.01(m,474H),0.55(m,4H),0.90(m,3H),1.33(m,6H),1.58(m,2H),1.96(s,6H),3.46(t,2H),3.70(t,2H),4.34(t,2H)，Mn＝6300g/mol。

(2) Synthesis of Polymer:

251.0mg (0.04mmoL) of PDMS-Br initiator, 11.4mg (0.08mmoL) of cuprous bromide and 2mg of OS were thoroughly mixed in a Schlenk tube, the Schlenk tube was connected to a double row tube, a vacuum pump was turned on, and oxygen in the Schlenk tube was removed; monomer isobutyl methacrylate (IBM) was charged in the molar ratio of the initiator starting from Table 1, dissolved in 3mL of anisole, and 21.7. mu.L (0.08mmoL) of 1,1,4,7,10, 10-hexamethyltriethylenetetramine was added to inject the mixed solution into a Schlenk tube using a syringe. Stirred at 80 ℃ in an oil bath for 24 h. After the reaction is finished, diluting the reaction solution with a small amount of dichloromethane, slowly dropwise adding the diluted reaction solution into 100mL of glacial methanol to obtain polymer precipitate, performing suction filtration on the polymer precipitate, washing the polymer precipitate for 3 times with methanol, and drying the washed polymer precipitate in a vacuum oven.

The information on each polymer is shown in table 1.

TABLE 1

In Table 1, a represents the ratio of the initial molar amount of the monomer to the initial molar amount of the initiator. b represents the conversion rate calculated according to the nuclear magnetic hydrogen spectrum. c represents the number average molecular weight obtained by gel permeation chromatography. d represents the number average molecular weight calculated from nuclear magnetic hydrogen spectroscopy. e represents the polydispersity obtained according to gel permeation chromatography.

The polymers P1-P3 prepared in this example were subjected to a pressure sensing performance test as follows:

spraying 200 μ L of ISSI FIB primer on a circular aluminum plate with a diameter of 1cm, and drying in an oven at 60 ℃ for 30 minutes. Dissolving 25mg of different high molecular polymers into 1mL of toluene, spraying 200 mu L of the solution onto a dried aluminum plate, and then sprayingAnd (5) putting the sample plate into a 60 ℃ oven to be dried for 30 minutes to obtain a sample plate sprayed with different macromolecules. The sample plate was placed in the instrument as shown in fig. 1. The pressure in the chamber was adjusted (10-190kPa), pictures of each sample plate at different pressure times were recorded using a color camera, and the luminous intensity of the sample plate at different pressure times was obtained by software Image J. According to the Stern-Volmer equation (formula 1), the luminous intensities at 100kPa and 100kPa are selected as P_ref、I_refAnd substituting the other pressure moments and the corresponding luminous intensities into a formula 1 to obtain a fitting curve of the luminous intensity and the pressure of each sample plate. Combining the fitting curve of the luminous intensity and the pressure of each sample plate, and obtaining the pressure sensitivity S of each sample plate according to the formula 2_P。

S_PEither B +2C (formula 2)

Where I is the luminous intensity of the sample plate at the different pressure moments, A, B, C is a temperature-dependent constant, P is the pressure at the different moments, I_refand/I represents the rate of change of the luminous intensity in response to pressure.

The results of the pressure test of polymer P1 at 20 ℃ are shown in fig. 2, and the results of the linear fit of each polymer sample plate at different pressure times at 20 ℃ are summarized in fig. 3. As can be seen from the results of FIG. 2, with increasing pressure, I_refthe/I is gradually increased, namely the luminous intensity is gradually increased. According to the linear fitting result of FIG. 3 and the combination of equation 2, the pressure sensitivity S of each polymer sample plate at 20 ℃ and the pressure variation range of 10-190kPa can be obtained_PRespectively, 0.82%/kPa, 0.81%/kPa, and 0.79%/kPa. From this result, it can be seen that the pressure sensitivity of each polymer sample plate is gradually decreased as the content of polydimethylsiloxane in the polymer is decreased. Unicoat PSP (20 ℃, S) from ISSI, USA_P0.5%/kPa) and UniFIB PSP (20 ℃, S)_P0.7%/kPa) each polymer sample plate had a higher pressure sensitivity.

The temperature (20-50 ℃) and the pressure in the chamber were adjusted, photographs of the P1 sample plate at different temperatures and different pressures were recorded using a color camera, and the luminous intensity of the P1 sample plate at different temperatures and different pressure times was obtained by software Image J. According to the Stern-Volmer equation (formula 1), selecting the luminous intensity at each temperature of 100kPa and each temperature of 100kPa as P_ref、I_refAnd substituting the luminous intensities corresponding to the different temperatures, different pressure moments and other temperatures into the formula 1 to obtain a fitting curve of the luminous intensity and the pressure of the P1 sample plate. Combining the fitting curves of the luminous intensity and the pressure of the P1 sample plate at different temperatures and different pressure moments, and obtaining the pressure sensitivity S of the P1 sample plate at different temperatures according to the formula 2_P。

As shown in FIG. 4, which shows the pressure test results of the polymer P1 sample plate at different temperature moments, it can be seen that the pressure sensitivity S of the P1 sample plate is increased with increasing temperature_PBecoming progressively larger. FIG. 5 shows the fitting curve of the luminous intensity and pressure of the polymer P1 sample plate at different temperatures and different pressures, and the pressure sensitivity S of the P1 sample plate at 20 deg.C, 30 deg.C, 40 deg.C, and 50 deg.C is obtained by combining formula 2_PRespectively, 0.82%/kPa, 1.00%/kPa, 1.28%/kPa, and 1.74%/kPa.

The applicant states that the present invention is illustrated by the above examples to the polymeric pressure sensitive lacquer and the preparation method and application thereof, but the present invention is not limited to the above examples, i.e. it does not mean that the present invention must be implemented by means of the above examples. It will be apparent to those skilled in the art that any modification of the present invention, equivalent substitutions of selected materials and additions of auxiliary components, selection of specific modes and the like, which are within the scope and disclosure of the present invention, are contemplated by the present invention.