WO2023029164A1 - Amphiphilic siloxane gel and preparation method therefor - Google Patents

Abstract

An amphiphilic siloxane gel, comprising an active species which is one of or a mixture of several organic bases having quaternary ammonium salt groups or alkylphosphonium hydroxide groups. Raw materials for the gel further comprise cyclic siloxane and a lubricating liquid. The amphiphilic siloxane gel uses simple materials, is simple and feasible in terms of synthesis process, green and environmentally-friendly, has high yield and a low preparation cost, and is easy to promote; moreover, the amphiphilic siloxane gel has adjustable surface adhesion and mechanical performances, can effectively reduce the adsorption of marine fouling organisms, and shows good antibacterial performance due to the introduction of positive charge groups; and the gel can regulate the chemical balance of catalytic degradation by means of regulating and controlling the content of the active species and the swelling degree of the functional lubricating liquid so as to control the self-polishing rate of a coating, and has a wide application prospect in the aspect of marine organism fouling resistance.

Description

A kind of amphiphilic silicone gel and preparation method thereof technical field

The invention relates to the field of organic materials, in particular to an amphiphilic siloxane gel and a preparation method thereof.

Background technique

In order to adapt to environmental requirements, increase the life of equipment and facilities, and protect the performance of equipment and facilities, many fields have anti-pollution needs. Antifouling coating is a commonly used antifouling method, which has a wide range of application requirements in marine engineering, chemical industry and other fields. However, the existing antifouling coating technology often has a single application scenario. For example, self-polishing type is usually used in marine applications. Or bactericidal/anti-adhesive release coating, this anti-fouling method will not only involve environmental protection issues, but also cannot be applied in other application scenarios that are unexpected in the marine environment. Although a few low surface energy coatings have been used as antifouling coatings, their mechanism of action is single, and they usually show low antifouling efficiency for complex polluted environments.

Silicone gel has excellent heat resistance, weather resistance, oil resistance, cold resistance, electrical insulation properties, low elastic modulus and low stress, and low cost, and has a wide range of applications in industry and daily life. However, the main preparation method of the existing siloxane gel is to form a network without dynamic properties through chemical crosslinking and curing/vulcanization, and because the raw material only contains silane with low surface energy, the prepared material is only hydrophobic, so The use of existing siloxane gels as low surface energy antifouling and anti-adhesion coatings has the following disadvantages: 1. The anti-fouling mechanism is single, and the anti-fouling and anti-adhesion properties shown are limited for complex polluted environments; 2. The thermosetting network is not reversible, and the coating cannot be recycled; 3. After the coating function is lost, it is difficult to maintain and remove; 4. Due to its fixed lubricant content, its antifouling validity period also has an upper limit.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the defects of the prior art silicone gel as an antifouling and anti-adhesion coating, thereby providing an amphiphilic silicone gel and a preparation method thereof.

For this reason, the present invention adopts following technical scheme.

The invention provides an amphiphilic siloxane gel, the gel contains active species, and the active species is one or more organic bases with quaternary ammonium salt groups or alkyl phosphorus hydroxide groups mix.

Further, the structural formula of the organic base is as follows:

one of

Among them, R0 is

one of

R ₁ is C _a H _2a+1 , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R are the same structure or a combination of different structures in C _b H _2b+1 and phenyl, 0<n<100, 0<a<8, 0<b<20. The amphiphilic siloxane gel described in the present application includes the following raw materials in parts by mass:

Active species 2.5-15 parts

Cyclic siloxane 85-97.5 parts

Lubricating fluid 40-150 parts.

Preferably, the cyclic siloxane is hexamethylcyclotrisiloxane, octamethylcyclotetraoxosiloxane, cyclotetramethicone, tetramethyltetravinylcyclotetrasiloxane, 2,4,6,8-Tetramethyl-2,4,6,8-tetra(3,3,3-trifluoropropyl)cyclotetrasiloxane, octaphenylcyclotetrasiloxane, heptamethyl phenylcyclotetrasiloxane, 1,3,5,7-tetrakis(diphenylphosphinoethyl)tetramethylcyclotetrasiloxane, tetramethyltetraphenylcyclotetrasiloxane, methyl Acrylic acid allyl trioxocyclosiloxane, tetraepoxycyclosiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclosiloxane One or more combinations of hexasiloxane and tetradecylmethylcyclohexasiloxane.

The lubricating liquid is one or more combinations of silicone oil derivatives such as dimethyl silicone oil and phenyl silicone oil, fluorinated polyether oil and mineral oil, and the viscosity of the lubricating liquid is 10-1000 cst.

The present invention also provides a preparation method for the above-mentioned amphiphilic siloxane gel, comprising the following steps:

S1: mixing the active species and cyclic siloxane, and then ring-opening polymerization to obtain a gel substrate;

S2: Soak the gel base material in a lubricating solution to obtain an amphiphilic silicone gel.

Further, the mixing in S1 is to stir and mix uniformly at 60-100°C at a stirring rate of 200-1000r/min, and the ring-opening polymerization is to react at 40-200°C for 3-40h under nitrogen or inert gas conditions, Then cool to room temperature.

8. The preparation method according to claim 6 or 7, characterized in that the soaking time in S2 is 6-36h, and the soaking temperature is 25-50°C.

In step S1, if the mixing effect of the active species and the cyclic siloxane is not good, silicone oil or an organic solvent can be added for assistance, wherein the organic solvent can be one of toluene, n-hexane, acetone or tetrahydrofuran.

The present invention also provides the application of the above-mentioned amphiphilic siloxane gel, which is applied to the preparation of antifouling coating

The technical solution of the present invention has the following advantages:

(1) In the present invention, an organic base with a specific group is used as an active species, which has multiple functions in the preparation of a gel: first, as a polymerization catalyst, it catalyzes ring-opening polymerization of cyclic siloxane to synthesize a gel. Adhesive substrate; secondly, it can be used as an electrostatic interaction aggregation unit to form a microphase separation structure. The active species is the main body of the hydrogel microphase. In the final gel material, the charge interaction of this phase is coordinated with the hydrogen bond interaction. The effect realizes the physical crosslinking and toughening of the material, so that the material has high toughness and high elastic mechanical properties; finally, the active species also acts as an active catalyst, so that the molecular bonds forming the gel substrate have dynamic reversible breaking/generation characteristics, thus endowing Gel degradability/self-polishing.

(2) In the material of the present invention, the active species is hydrophilic, and the siloxane is hydrophobic, and when the prepared gel is used as a coating, it has a super slippery effect on the water-oil system.

(3) The present invention introduces a lubricant into the gel. During use, along with the loss of the surface lubricant, the lubricant inside the gel material will continue to be secreted and replenished to the surface to maintain the lubricating effect.

(4) The active species catalyst in the present invention is a typical cationic group, and the introduction of the ionic group makes the final amphiphilic superslip gel have excellent antibacterial properties.

(5) The amphiphilic siloxane gel of the present invention can also be gradually degraded into polydimethylsiloxane and the alkyl compound corresponding to the active species catalyst under the catalysis of its own active species. The degradation condition is an open system, and as the temperature rises, the degradation speed is accelerated; the gel can also realize the reversible dynamic exchange of silicon-oxygen bonds under the catalysis of its own active species, and help it to recover from high internal stress. The nonlinear cross-linked network is transformed into a linear non-cross-linked network with small internal stress, which can better achieve the purpose of degradation.

(6) The amphiphilic siloxane gel obtained by the present invention has self-polishing and antifouling properties when used as a coating. With the loss of the lubricating fluid in the gel, when the lubricating fluid in the material is less or can no longer secrete the lubricating fluid, there will be The active species in the gel phase of the material will catalyze the degradation of the material, supplement the lubricating fluid, and then achieve continuous secretion, and finally achieve the degradation of the entire amphiphilic siloxane gel coating; at the same time, by selecting the appropriate active species content and lubricating fluid swelling degree , while meeting the mechanical performance requirements in antifouling coating applications, the chemical balance of catalytic degradation of active species can be controlled to achieve coating self-polishing rate control.

Description of drawings

In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the following will briefly introduce the accompanying drawings that need to be used in the specific implementation or description of the prior art. Obviously, the accompanying drawings in the following description The drawings show some implementations of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative work.

Fig. 1 is the nuclear magnetic spectrum of the gel substrate obtained in the embodiment of the present invention 1;

Fig. 2 is the physical figure of the gel obtained in the embodiment of the present invention 1;

Fig. 3 is a schematic diagram of the dynamic network structure of the amphiphilic siloxane gel obtained in Example 1 of the present invention;

Fig. 4 is the morphological diagram of the surface of the amphiphilic silicone gel obtained in Example 1 of the present invention;

Fig. 5 is the compressive stress-strain curve of the gel substrate obtained in Example 1 of the present invention;

Fig. 6 is the antibacterial effect experiment figure in the present invention's test example 3;

Fig. 7 is the antifouling effect experiment figure in the present invention's test example 3;

Fig. 8 is the effect of the active species content on the release amount when the swelling degree of the lubricating liquid is 100% of the base material in Test Example 4 of the present invention;

Fig. 9 is when active species content is 10% of cyclic silane monomer in test example 4 of the present invention, the influence of lubricating fluid swelling degree on release amount;

Fig. 10 is a comparison chart of viscosities of the gel materials obtained in Example 1 and Comparative Example 1 in Test Example 5 of the present invention under complex conditions.

Detailed ways

Example 1

This embodiment provides an amphiphilic siloxane gel, the preparation method of which is as follows:

(1) Take 10g of octamethylcyclotetraoxosilane, add 0.5g of tetramethylammonium silanol, stir and mix evenly at 80°C, then place it in a nitrogen atmosphere at 85°C for 12 hours, and place it in an open environment at room temperature after the reaction is completed After cooling to room temperature, the gel base material can be obtained, and its NMR image is shown in Figure 1. At 0 ppm, there is an obvious peak of a methyl group connected to silicon, and at 3.25 ppm, there is an obvious peak of a methyl group connected to nitrogen. peak;

(2) Soak the obtained gel base material in 50cst of simethicone oil to balance to obtain the amphiphilic silicone gel. The physical picture of the material is shown in Figure 2, and it can be seen that it is a translucent elastomer. Its structure is shown in Figure 3, which is a dynamic network.

Example 2

This embodiment provides an amphiphilic siloxane gel, the preparation method of which is as follows:

(1) Take 20g of decamethylcyclopentasiloxane, add 0.5g of tetrabutylphosphine hydroxide, stir and mix evenly at 60°C, then place it in a nitrogen atmosphere at 100°C for 12 hours, and place it in an open environment at room temperature after the reaction is completed , the gel substrate can be obtained after cooling to room temperature;

(2) Soak the obtained gel substrate into 20 cst of simethicone oil to balance to obtain amphiphilic silicone gel.

Example 3

This embodiment provides an amphiphilic siloxane gel, the preparation method of which is as follows:

(1) Take 30g of dodecamethylcyclohexasiloxane, add 0.5g of tetrabutylammonium hydroxide, stir and mix evenly at 90°C, then place it in a nitrogen atmosphere at 60°C for 20h, and place it in an open environment at room temperature after the reaction is completed In, after cooling to room temperature, the gel substrate is obtained;

(2) Soak the obtained active gel base material in 1000cst of simethicone oil to balance to obtain the amphiphilic silicone gel.

Comparative example 1

This comparative example provides a conventional silicone gel, and the difference from Example 1 is that a platinum catalyst is used to catalyze the addition reaction to cure to prepare a chemically crosslinked silicone elastomer, and the elastic gel obtained by swelling the silicone oil with a viscosity of 1000cst body, thereby preparing an inactive, non-amphiphilic silicone gel.

Comparative example 2

This comparative example provides a conventional antifouling coating, which is the silicone antifouling paint Hempaguard X7 89900 produced by Hempel Company.

Test example 1

The gel base material obtained in Example 1 was measured on an Instron-instron-9347 universal material testing machine to measure a compressive stress-strain curve, as shown in FIG. 4 . It can be seen from the figure that no significant change in the compressive stress-strain curve was observed in the 10,000-cycle test, indicating that the material has excellent mechanical properties.

Test example 2

The amphiphilic siloxane gel obtained in Example 1 is made into a coating, and its super slippery effect is shown in FIG. 5 . It can be seen that, compared with the surface of the material without silicone oil, the droplet can roll to the edge within 30s on the surface of the super-slip gel coating of the active amphiphilic super-slip gel, while the surface of the material without silicone oil only shows little Short rolling distance.

Test example 3

The amphiphilic siloxane gel obtained in Example 1 is made into a coating, and the blank metal surface and the conventional antifouling coating in Comparative Example 2 are used for antibacterial performance testing and anti-seaweed adhesion testing. The effect comparison is shown in Figure 6 respectively. and shown in Figure 7. The amphiphilic siloxane gel showed obvious antibacterial effect with a bacteriostatic rate greater than 90, while showing a low algae adsorption rate.

Antibacterial performance test method:

Escherichia coli (DH5α wild-type) was incubated in 5ml LB medium at 37°C for 12h, and 3ml of bacterial suspension was added to Luria-Bertani (LB) medium with a concentration of about 109CFU/ml to soak each sample. Three groups of experimental samples were incubated at room temperature for 24 hours. After incubation, the specimens were removed from the bacterial suspension. Each sample was lightly washed 3 times with 1 ml PBS. Then, stain with live/dead BacLight ^™ Bacterial Survival Kit (Thermo Fisher) for 15 minutes. Then, the samples were washed 3 times with PBS to remove excess fuel, and then observed under a fluorescence microscope.

Anti-algae adhesion test method:

The blank metal sheet, the metal sheet coated with the amphiphilic siloxane gel coating obtained in Example 1, and the metal sheet coated with the conventional antifouling coating in Comparative Example 2 were soaked in three groups of samples containing a concentration of 1g/ In the first-generation seaweed culture solution of L and placed in a constant temperature box, DMEM culture solution was added every 12 hours to make the seaweed grow. After one week, the three groups of samples were taken out, washed slightly in deionized water, and photographed, using the image size molecule in the software image pro counts the seaweed coverage on the sample surface.

Test example 4

(1) adopt the raw material of embodiment 1, the lubricating fluid swelling degree is 100wt% of base material, adjusts active species consumption to be respectively 5wt%, 7.5wt%, 10wt%, 15wt% of base material, is used for detecting active species content to mechanical Performance, the impact of degradation/self-polishing performance, the results are shown in Table 1 and Figure 8, wherein the degradation/self-polishing performance is expressed by the amount of lubricating fluid released after the gel is left to stand for a certain period of time:

Release amount = (initial weight of the gel - weight after wiping off the lubricating fluid on the surface of the gel)/initial weight of the gel:

Table 1: Effect of active species content on mechanical properties

Active species content (%)	5	7.5	10	15
Elastic modulus (MPa)	1.2	1.32	1.78	2.84

It can be seen from the above table that the higher the content of active species, the better the mechanical properties, and it can be seen from Figure 8 that the release is lower.

(2) Using the raw materials of Example 1, the amount of active species is 10wt% of the substrate, and the swelling degree of the lubricating solution is adjusted to 150wt%, 100wt%, 75wt%, and 50wt% of the substrate, respectively, to explore the effect of the active species content on the mechanical properties, The impact of degradation/self-polishing performance, the results are shown in Table 2 and Figure 9, wherein the degradation/self-polishing performance is expressed by the amount of lubricating fluid released after the gel is left to stand for a certain period of time:

Release amount = (initial weight of the gel - weight after wiping off the lubricating fluid on the surface of the gel)/initial weight of the gel:

Table 2 Effect of lubricating fluid swelling degree on mechanical properties

Swelling degree of lubricating fluid (%)	150	100	75	50
Elastic modulus (MPa)	0.74	0.96	1.2	1.6

It can be seen from the above table that the lower the swelling degree of the lubricating fluid, the better the mechanical properties, and it can be seen from Figure 9 that the release amount is lower.

It can be seen that by changing the swelling degree of the lubricating fluid and the content of active species, the mechanical properties and degradation/self-polishing properties can be adjusted to achieve the desired effect.

Test example 5

The materials obtained in Example 1 and Comparative Example 1 were used for viscosity comparison under complex conditions. As shown in Figure 10, on the sample that is coated with embodiment 1 (upper left) and comparative example 1 (upper right), drop and disperse surfactant (5% of Tween 80 and 5% of molecular weight are 2000 polyethylene Glycol) aqueous solution droplets (red) are about 5 microliters and 25 microliters respectively, and the sizes of ethanol solution droplets (blue) dispersed with surfactant are about 5 microliters and 25 microliters respectively. Three drops of 25 microliters of liquid are placed, and the entire sample is placed on a table with an inclination angle of 10°, and the movement of the liquid droplets on the coating surface is observed.

It can be seen from FIG. 10 that both kinds of droplets can be seen to slide off the sample sheet of Example 1 without sticking. However, on the sample in Comparative Example 1, the small droplets all spread out directly and could not slide. After 60 seconds, the blue droplets and red droplets on the sample in Example 1 (lower left) all slid away, and did not adhere to the On the coating, on the sample in Comparative Example 1 (lower right), both droplets spread out to adhere to the coating surface. That is to say, the sample prepared in Example 1 of the present invention, compared with the conventional silicone gel in Comparative Example 1, can deal with more complicated adherents.

Apparently, the above-mentioned embodiments are only examples for clear description, rather than limiting the implementation. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. And the obvious changes or changes derived therefrom are still within the scope of protection of the present invention.

Claims (9)

1. An amphiphilic siloxane gel, characterized in that, the gel contains active species, and the active species is one or more organic bases with quaternary ammonium salt groups or alkyl phosphorus hydroxide groups mix.
2. The gel according to claim 1, wherein the structural formula of the organic base is

   

   

   one of

   Among them, R0 is

   

   

   one of

   R ₁ is C _a H _2a+1 , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ , and R are the same structure or a combination of different structures in C _b H _2b+1 and phenyl, 0<n<100, 0<a<8, 0<b<20.
3. The gel according to claim 1 or 2, characterized in that, comprising the following raw materials in parts by mass:

   Active species 2.5-15 parts

   Cyclic siloxane 85-97.5 parts

   Lubricating fluid 40-150 parts.
4. The gel according to claim 3, wherein the cyclic siloxane is hexamethylcyclotrisiloxane, octamethylcyclotetraoxosiloxane, cyclotetrapolydimethylsiloxane, tetramethicone, Methyltetravinylcyclotetrasiloxane, 2,4,6,8-Tetramethyl-2,4,6,8-tetrakis(3,3,3-trifluoropropyl)cyclotetrasiloxane, Octaphenylcyclotetrasiloxane, Heptamethylphenylcyclotetrasiloxane, 1,3,5,7-Tetrakis(diphenylphosphinoethyl)tetramethylcyclotetrasiloxane, Tetramethyl tetraphenylcyclotetrasiloxane, methacrylic trioxocyclosiloxane, tetraepoxycyclosiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, decamethyl One or more combinations of cyclopentasiloxane, dodecamethylcyclohexasiloxane and tetradecamethylcyclohexasiloxane.
5. The gel according to claim 3 or 4, wherein the lubricating liquid is one or more combinations of silicone oil derivatives such as dimethyl silicone oil and phenyl silicone oil, fluorinated polyether oil and mineral oil, The viscosity of the lubricating liquid is 10-1000cst.
6. The method for preparing amphiphile gel described in any one of claims 1-5, is characterized in that, comprises the steps:

   S1: mixing the active species and cyclic siloxane, and then ring-opening polymerization to obtain a gel substrate;

   S2: Soak the gel substrate in a lubricating solution to obtain an amphiphilic gel.
7. The preparation method according to claim 6, characterized in that, the mixing in S1 is stirring and mixing uniformly at 60-100°C at a stirring rate of 200-1000r/min, and the ring-opening polymerization is under nitrogen or inert gas conditions React at 40-200°C for 3-40h, then drop to room temperature.
8. The preparation method according to claim 6 or 7, characterized in that the soaking time in S2 is 6-36h, and the soaking temperature is 25-50°C.
9. The application of the amphiphilic siloxane gel according to any one of claims 1-5, characterized in that it is applied to the preparation of antifouling coatings.

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