Photocurable hydrophilic carboxyl modified organic silicon polymer as well as preparation method and application thereof

Abstract

The invention discloses a photocurable hydrophilic carboxyl modified organosilicon polymer as well as a preparation method and application thereof. The preparation method of the carboxyl modified organic silicon polymer comprises the following steps: carrying out hydrolysis reaction and condensation reaction on raw materials comprising a cyclosiloxane monomer, a carboxyl-containing siloxane monomer and an acryloyloxy-containing siloxane monomer to obtain the carboxyl modified organic silicon polymer, the ratio of the sum of the molar weight of the siloxane monomer containing carboxyl and the siloxane monomer containing acryloyloxy to the molar weight of the cyclosiloxane monomer is (0.24-1.4): 1, the molar ratio of the siloxane monomer containing carboxyl to the siloxane monomer containing acryloyloxy is (1.3-5): 1, and the molar ratio of the siloxane monomer containing acryloyloxy to the cyclosiloxane monomer is (0.08-0.6): 1. According to the invention, carboxyl and acryloyloxy groups are introduced into a traditional siloxane material, so that the prepared coating has the characteristic of realizing rapid light curing at normal temperature, and the formed coating has hydrophilicity, adhesive force and flexibility.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of high polymer materials, and particularly relates to a photocurable and hydrophilic carboxyl-modified organosilicon polymer as well as a preparation method and application thereof. BACKGROUND

[0002] Nowadays, the use of biomedical devices (such as catheters, implants, endoscopes, etc.) has become one of the important means for modern medicine to diagnose and treat various diseases. In the field of biomedical devices, in order to avoid several clinical problems caused by the direct contact between the surface of the device and the human body tissue, such as human body rejection reaction, mechanical friction damage and nosocomial infection, measures need to be taken to improve the biocompatibility, surface lubricity and antibacterial performance of the device. Among them, constructing a functional coating on the surface of the device has become a relatively common solution. Polysiloxane materials (such as polydimethylsiloxane, also known as DMS) are considered as ideal medical device coating substrates due to their excellent biocompatibility, flexibility and chemical stability. In particular, the high flexibility of polysiloxane materials can endow the coating with excellent dynamic deformation adaptability and long-term durability, and is also suitable for situations where people are allergic to traditional materials such as latex. In addition, polysiloxane materials have selective permeability to oxygen and drug molecules, and are widely used in indwelling devices (such as artificial blood vessels, ureteral stents). However, polysiloxane materials represented by PDMS are inherently hydrophobic, which leads to defects in the surface lubricity and antibacterial performance of biomedical devices made of polysiloxane materials: significant stress is still generated when sliding in the body, and microbial adhesion is also more likely to occur.

[0003] In order to overcome the hydrophobicity of polysiloxane materials, researchers have attempted to modify the surface of polysiloxane materials to be hydrophilic. Patent No. CN120242174A provides a composite material of gamma-polyglutamic acid and hydrophilic polysiloxane, which significantly improves the hydrophilicity of the coating by introducing hydrophilic carboxyl groups into the siloxane system, thereby improving the antibacterial performance of the coating. However, the coating of the prior art needs to be dried and cured for a long time (5-10 hours) to form, which consumes time and energy. SUMMARY

[0004] In order to solve the problems of poor hydrophilicity and slow curing speed of existing polysiloxane coatings, the present application provides a preparation method of a carboxyl-modified organosilicon polymer, which significantly improves the hydrophilicity of siloxane and enables the coating prepared from the carboxyl-modified organosilicon polymer to have the performance of rapid photocuring.

[0005] Another object of the present application is to provide a carboxyl-modified organosilicon polymer.

[0006] Still another object of the present application is to provide the use of the carboxyl-modified organosilicon polymer described above in the preparation of a coating.

[0007] It is still another object of the present application to provide a coating containing the carboxyl-modified silicone polymer.

[0008] It is still another object of the present application to provide a method for using the coating.

[0009] It is still another object of the present application to provide an application of the coating in the field of biomedical devices.

[0010] The above objects of the present application are achieved by the following technical solutions: A preparation method of a carboxyl-modified silicone polymer, comprising the following steps: Raw materials including a cyclosiloxane monomer, a carboxyl-containing siloxane monomer, and an acryloyloxy-containing siloxane monomer undergo hydrolysis and condensation reactions to obtain the carboxyl-modified silicone polymer; The ratio of the sum of the molar amounts of the carboxyl-containing siloxane monomer and the acryloyloxy-containing siloxane monomer to the molar amount of the cyclosiloxane monomer is (0.24-1.4):1, the molar ratio of the carboxyl-containing siloxane monomer to the acryloyloxy-containing siloxane monomer is (1.3-5):1, and the molar ratio of the acryloyloxy-containing siloxane monomer to the cyclosiloxane monomer is (0.08-0.6):1.

[0011] It should be noted that: The inventors of the present application tried to introduce acryloyloxy groups into polysiloxane, which can be rapidly cured under light. However, the polysiloxane does not have hydrophilicity.

[0012] The inventors continued to study and found that, by using a cyclosiloxane monomer as a base monomer, a carboxyl-containing siloxane monomer and an acryloyloxy-containing siloxane monomer as functional monomers, regulating the ratio of the molar amount of the base monomer to the sum of the molar amounts of the two functional monomers and regulating the molar ratio of the two functional monomers, the coating prepared from the carboxyl-modified silicone polymer obtained by the reaction not only can rapidly form a coating through photocuring, has good hydrophilicity, but also has good adhesion and flexibility. The principle is as follows: The cyclosiloxane monomer as a base monomer is mainly used to form the main chain of the silicone polymer, ensuring that the coating has good flexibility; the acryloyloxy groups of the acryloyloxy-containing siloxane monomer in the functional monomers can be photocured and improve the crosslinking degree during curing of the coating, and the carboxyl groups of the carboxyl-containing siloxane monomer can improve the hydrophilicity and polarity of the coating.

[0013] The ratio of the molar amount of the base monomer to the sum of the molar amounts of the two functional monomers needs to be controlled within a suitable range, since the acryloyloxy group can increase the cross-linking degree of the coating during curing and the carboxyl group can increase the polarity of the coating, when the amount of the functional monomers gradually increases, the adhesion of the coating will be improved, but when the amount of the functional monomers further increases, the cohesive strength of the main chain formed by the base monomers will decrease, thereby degrading the adhesion of the coating, and also degrading the flexibility of the coating.

[0014] The molar ratio between the two functional monomers also needs to be controlled within a suitable range, when the amount of the carboxyl-containing siloxane monomer gradually increases relative to the amount of the acryloyloxy-containing siloxane monomer, the adhesion will first increase and then decrease, because when the amount of the carboxyl-containing siloxane monomer is relatively low relative to the acryloyloxy-containing siloxane monomer, the polarity of the coating is insufficient. When the amount of the carboxyl-containing siloxane monomer is relatively high relative to the acryloyloxy-containing siloxane monomer, the hydrogen bonds formed by the carboxyl groups will interfere with the cross-linking of the acryloyloxy groups, and insufficient cross-linking will result in a decrease in adhesion.

[0015] The amount of the acryloyloxy-containing siloxane monomer relative to the cyclosiloxane monomer should also not be too high, otherwise excessive cross-linking will occur, limiting the exposure of the carboxyl groups to the surface of the coating, resulting in poor hydrophilicity of the coating.

[0016] In addition, the carboxyl groups need to be introduced in the form of monomer polymerization in the present application, if the acryloyloxy-containing polysiloxane is prepared first and then the carboxyl groups are further introduced, the conditions required for introducing the carboxyl groups may cause the acryloyloxy-containing polysiloxane to cross-link prematurely, thereby failing to be further used as a coating.

[0017] In the present application, the ratio of the sum of the molar amounts of the carboxyl-containing siloxane monomer and the acryloyloxy-containing siloxane monomer to the molar amount of the cyclosiloxane monomer can be specifically 0.24:1, 0.3:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 1.2:1, 1.4:1, or a range formed by any two points; the molar ratio of the carboxyl-containing siloxane monomer to the acryloyloxy-containing siloxane monomer can be specifically 1.3:1, 2:1, 3:1, 4:1, 5:1, or a range formed by any two points.

[0018] Preferably, the molar ratio of the carboxyl-containing siloxane monomer to the cyclosiloxane monomer is (0.16-1):1, and can be specifically 0.16:1, 0.2:1, 0.27:1, 0.6:1, 0.8:1, 1:1, or a range formed by any two points.

[0019] In the present application, the molar ratio of the acryloyloxy-containing siloxane monomer to the cyclosiloxane monomer can be specifically 0.08:1, 0.1:1, 0.13:1, 0.2:1, 0.4:1, 0.6:1, or a range formed by any two points.

[0020] Preferably, the viscosity of the carboxyl-modified silicone polymer is 3000-3500 mPa·s.

[0021] Preferably, the carboxyl-containing siloxane monomer is a siloxane monomer containing a carboxyl group and two alkoxy groups.

[0022] More preferably, the alkoxy group is at least one of an ethoxy group or a methoxy group.

[0023] Preferably, the method for preparing the carboxyl-containing siloxane monomer comprises the following steps: mixing a mercapto-containing carboxylic acid and a carbon-carbon double bond-containing siloxane to perform a mercapto-alkene click reaction, thereby obtaining the carboxyl-containing siloxane monomer.

[0024] More preferably, the mercapto-containing carboxylic acid is at least one of mercaptoacetic acid or mercaptopropionic acid.

[0025] More preferably, the carbon-carbon double bond-containing siloxane is at least one of methyl vinyl dimethoxysilane or vinyl trimethoxysilane.

[0026] More preferably, the mercapto-alkene click reaction is performed under light conditions, the reaction temperature is 25-50°C, and the reaction time is 10-30 min.

[0027] Further preferably, the light is 350-380 nm ultraviolet light, the energy density is 40-60 mW / cm 2 .

[0028] More preferably, the mercapto-alkene click reaction is initiated by a photoinitiator.

[0029] Further preferably, the photoinitiator is a,a-dimethoxy-a-phenylacetophenone (DMPA).

[0030] More preferably, the mercapto-alkene reaction is performed under stirring.

[0031] Preferably, the acryloyloxy-containing siloxane monomer is a siloxane monomer containing an acryloyloxy group and 2-3 alkoxy groups.

[0032] More preferably, the acryloyloxy-containing siloxane monomer is at least one of 3-methacryloyloxypropyl trimethoxysilane, 3-methacryloyloxypropyl methyldimethoxysilane, 3-methacryloyloxypropyl methyldiethoxysilane, or acryloyloxypropyl trimethoxysilane.

[0033] Preferably, the cyclosiloxane monomer is at least one of octamethylcyclotetrasiloxane or decamethylcyclopentasiloxane.

[0034] Preferably, the raw material further comprises an end-capping agent.

[0035] More preferably, the hydrolysis reaction is carried out by mixing the end-capping agent, the carboxyl-containing siloxane monomer and the cyclic siloxane monomer, incubating at 35-65℃ for 1-3h, and then adding the acryloxy-containing siloxane monomer, and continuing to incubate at 35-65℃ for 1-3h.

[0036] More preferably, the end-capping agent is used in an amount of 0.3-0.6% of the total mass of the cyclic siloxane monomer, the carboxyl-containing siloxane monomer and the acryloxy-containing siloxane monomer.

[0037] Further preferably, the end-capping agent is at least one of hexamethyldisiloxane and tetramethyldisiloxane.

[0038] Preferably, the hydrolysis reaction is carried out in the presence of water.

[0039] More preferably, the hydrolysis reaction and the condensation reaction are carried out in the presence of an acid catalyst.

[0040] Further preferably, the acid catalyst comprises one or more of concentrated hydrochloric acid, concentrated sulfuric acid, p-toluenesulfonic acid, triflic acid, acetic acid, cation exchange resin, dibutyltin dilaurate and dibutyltin diacetate.

[0041] Preferably, the condensation reaction is carried out at a temperature of 75-95℃, for a time of 0.5-1h, and at a pressure of -0.2-0MPa.

[0042] Preferably, the hydrolysis reaction and the condensation reaction are carried out under stirring.

[0043] Preferably, after the condensation reaction, the method further comprises the steps of adding dichloromethane and an ethanol aqueous solution, oscillating, standing and removing the solvent.

[0044] The dichloromethane is added to dissolve the carboxyl-modified silicone polymer, and the ethanol aqueous solution is added to remove the acid catalyst.

[0045] More preferably, the method for removing the solvent is reduced pressure distillation.

[0046] Further preferably, the reduced pressure distillation is carried out at a pressure of -0.1--0.05MPa, a temperature of 25-70℃, and for a time of 0.5-2h.

[0047] The present application also protects a carboxyl-modified silicone polymer prepared by the above method.

[0048] The present application also protects the use of the carboxyl-modified silicone polymer in preparing a coating material.

[0049] The application also protects a coating, comprising the following components in parts by weight: The carboxyl-modified silicone polymer is 100 parts, The photoinitiator is 0.5-3 parts.

[0050] Preferably, the coating comprises the following components in parts by weight: The carboxyl-modified silicone polymer is 100 parts, The photoinitiator is 1-3 parts.

[0051] Preferably, the coating further comprises 11-18 parts of a neutralizing agent.

[0052] The neutralizing agent can react with the carboxyl groups in the carboxyl-modified silicone polymer to form groups that are more easily ionized, and the coating has higher hydrophilicity.

[0053] More preferably, the neutralizing agent is at least one of triethylamine and triethanolamine.

[0054] Preferably, the photoinitiator is at least one of photoinitiator 2959, photoinitiator 1173, photoinitiator benzophenone, photoinitiator TPO-L, photoinitiator TPO, photoinitiator 184, photoinitiator 819, and photoinitiator ITX.

[0055] The preparation method of the coating comprises the following steps: mixing the components to obtain the coating.

[0056] The application also protects a use method of the coating, comprising the following steps: The coating is applied to an object, and light curing is performed to form a coating.

[0057] Preferably, the light used for light curing is light of a wavelength that the photoinitiator used can respond to.

[0058] The application also protects the use of the coating in the biomedical device field.

[0059] Compared with the prior art, the application has the following beneficial effects: The coating prepared from the carboxyl-modified silicone polymer obtained by the reaction of the cyclosiloxane monomer as the base monomer, the carboxyl-containing siloxane monomer and the acryloxy-containing siloxane monomer as the functional monomers, the regulation of the molar mass of the base monomer and the sum of the molar masses of the two functional monomers, and the regulation of the molar ratio of the two functional monomers, not only can quickly form a coating through light curing, but also has good hydrophilicity, good adhesion, and good flexibility, and has great utilization value in the biomedical device field. BRIEF DESCRIPTION OF DRAWINGS

[0060] Figure 1The Fourier transform infrared spectroscopy (FTIR) chart of the coating B formed in Example 1.

[0061] Figure 2 The chart of the photorheological test results of the photocuring process of the coating B prepared in Example 1. DETAILED DESCRIPTION

[0062] The present application is further illustrated in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present application in any form. Unless otherwise specified, the reagents, methods and equipment used in the present application are the conventional reagents, methods and equipment in the technical field.

[0063] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0064] Example 1 The present example provides a carboxyl-modified silicone polymer and a coating prepared therefrom, a preparation method of the carboxyl-modified silicone polymer, comprising the following steps: (1) Preparation of carboxyl-containing siloxane monomer: a disposable plastic cup is added with mercaptopropionic acid and methyl vinyl dimethoxysilane in a molar ratio of 1:1, and then 2% of the total mass of mercaptopropionic acid and methyl vinyl dimethoxysilane is added with a photoinitiator DMPA, and the obtained product is irradiated under 365 nm, 50 mW / cm 2 of ultraviolet light for 10 minutes to obtain the carboxyl-containing siloxane monomer.

[0065] (2) Preparation of carboxyl-modified silicone polymer: the carboxyl-containing siloxane monomer (0.06 mol) obtained in step (1) is added to a four-necked flask with octamethylcyclotetrasiloxane (0.1 mol), deionized water (0.28 mol), trifluoromethanesulfonic acid, and capping agent hexamethyldisiloxane, respectively, and equipped with a stirrer, a thermometer and a condenser, and then hydrolyzed at 65 ℃ for 1 h, and then 3-methacryloyloxypropylmethyldimethoxysilane (0.02 mol) is slowly added dropwise through a constant pressure funnel, and then hydrolyzed at 65 ℃ for 1 h, and then the temperature is raised to 95 ℃, and then reacted at -0.1 MPa for 30 minutes. Ethanol aqueous solution (ethanol and water in a mass ratio of 3:1) and dichloromethane (DCM) are added, and then shaken and left to stand, and then the dichloromethane layer is taken, and then distilled under reduced pressure at 55 ℃ to obtain a light yellow transparent silicone oil, which is the carboxyl-modified silicone polymer, and the viscosity of the carboxyl-modified silicone polymer is about 3196 mPa·s. The mass of trifluoromethanesulfonic acid and capping agent hexamethyldisiloxane is 0.5% of the total mass of the carboxyl-containing siloxane monomer, octamethylcyclotetrasiloxane and 3-methacryloyloxypropylmethyldimethoxysilane in the present example.

[0066] The coating A of the present example comprises the following components in parts by weight: carboxyl-modified silicone polymer 100 parts, photoinitiator TPO-L 2 parts.

[0067] The coating B of the present example comprises the following components in parts by weight: carboxyl-modified silicone polymer 100 parts, photoinitiator TPO-L 2 parts, triethylamine 11 parts.

[0068] Examples 2-9, Comparative Examples 1-2 Examples 2-9, Comparative Examples 1-2 and Example 1 differ in that in step (2), the amounts of carboxyl-containing siloxane monomer, octamethylcyclotetrasiloxane and 3-methacryloyloxypropylmethyldimethoxysilane are different, and the amounts of each raw material are shown in Table 1.

[0069] Table 1 Amounts of raw materials in Examples 1-9, Comparative Examples 1-2

[0070] Sample characterization and performance testing The coating of each example and comparative example was coated on a tinplate to form a liquid coating, and cured to form a shape under a LED lamp with a wavelength of 405 nm.

[0071] The molecular structure of the coating formed by coating B of Example 1 was characterized by Fourier transform infrared spectroscopy, and the results are shown in Figure 1 Figure. In the figure, 1722 cm -1 is the characteristic absorption peak of C=O stretching vibration of carboxyl; 1644 cm -1 is the characteristic absorption peak of C=C stretching vibration of acryloyloxy group which has not participated in the reaction; 1250 cm -1 is the characteristic absorption peak of Si-CH3 bending vibration; 1000-1150 cm -1 is the characteristic absorption peak of Si-O-Si stretching vibration. The above characteristic peaks represent the expected structure in the obtained coating.

[0072] The contact angle tester (Shanghai Yingnuo Precision Instrument Co., Ltd., CA-100 type) was used to test the water contact angle of the coating formed by each example and comparative example, and the results are shown in Table 2.

[0073] According to the ISO 2409 standard, the adhesion of the coating B formed by each example and comparative example was tested. According to the coating peeling condition, the coating adhesion grade can be divided into 1, 2, 3, 4, 5 levels from good to bad, and the results are shown in Table 2.

[0074] The flexibility of the coating was characterized by bending test using a QTX type paint film elasticity tester according to the national standard GB1731-79. The coating sample was subjected to bending test using shaft rods with different diameters, and the minimum shaft rod diameter that could cause damage to the coating structure was determined. The smaller the minimum shaft rod diameter, the better the flexibility of the coating. The results are shown in Table 2.

[0075] Table 2 Contact angle, adhesion, and flexibility test results of the coating of each example and the comparative example

[0076] As can be seen from Table 2, the contact angle of the coating formed by the coating A prepared in Examples 1-9 is not more than 93.35°, the contact angle of the coating formed by the coating B is not more than 92.74°, the adhesion grade of the coating is not less than 4, and the minimum shaft rod diameter of the coating is not more than 10 mm, indicating that the carboxyl-modified silicone polymer provided by the present application has good hydrophilicity, adhesion, and flexibility.

[0077] In addition, the coating A of Examples 1-9 also has good adhesion and flexibility.

[0078] The amount of the carboxyl-containing siloxane monomer and the acryloxy-containing siloxane monomer in Comparative Example 1 is too small, and the coating prepared from the carboxyl-modified silicone polymer has good hydrophilicity, but poor adhesion and flexibility.

[0079] The amount of the functional monomer in Comparative Example 2 is too high, and the amount of the base monomer is small, especially, the amount of the acryloxy-containing siloxane monomer is too high relative to the amount of the carboxyl-containing siloxane monomer, and the coating formed by the carboxyl-modified silicone polymer has poor hydrophilicity and poor flexibility.

[0080] The light rheological test was performed using a rotary rheometer to determine the light gelation time of the light curing process of the coating B of Example 1. The constant strain mode was selected, the strain γ0 was fixed at 1%, the oscillation frequency was 1 Hz, the gap was set to 0.1 mm, the irradiation intensity was 30 mW / cm 2 , the test time was 300 s, the point light source with a wavelength of 405 nm was turned on at about 100 s, and the collection time interval was 1 s. The changes of the storage modulus (G') and the loss modulus (G") during the test were monitored, and it was generally considered that the intersection of the two was the light gel point. From Figure 2 It can be seen that the gel point of the coating of Example 1 appears at 3.4 s after irradiation, and reaches the plateau within 20 s, indicating that the coating can complete light curing within 20 s, and the curing rate is fast. The light rheological test results of the coatings of other examples are similar to those of Example 1, indicating that the coating made of the carboxyl-modified silicone polymer of the present application can realize rapid light curing.

[0081] Obviously, the above-mentioned embodiments of the present application are only examples for clearly illustrating the present application, but not limitation on the embodiments of the present application. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and also impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method for preparing a photocurable, hydrophilic carboxyl-modified organosilicon polymer, characterized in that, Includes the following steps: Raw materials including cyclosiloxane monomers, carboxyl-containing siloxane monomers and acryloyloxy-containing siloxane monomers undergo hydrolysis and condensation reactions to obtain carboxyl-modified organosilicon polymers. The molar ratio of the sum of the carboxyl-containing siloxane monomers and the acryloxy-containing siloxane monomers to the molar ratio of the cyclosiloxane monomers is (0.24~1.4):1, the molar ratio of the carboxyl-containing siloxane monomers to the acryloxy-containing siloxane monomers is (1.3~5):1, and the molar ratio of the acryloxy-containing siloxane monomers to the cyclosiloxane monomers is (0.08~0.6):

1.

2. The preparation method according to claim 1, characterized in that, The carboxyl-containing siloxane monomer is a siloxane monomer containing a carboxyl group and two alkoxy groups.

3. The preparation method according to claim 1, characterized in that, The acryloyloxy-containing siloxane monomer is a siloxane monomer containing acryloyloxy and 2 to 3 alkoxy groups.

4. The preparation method according to claim 1, characterized in that, The viscosity of the carboxyl-modified organosilicon polymer is 3000~3500 mPa·s.

5. A carboxyl-modified organosilicon polymer, characterized in that, It is prepared by any of the preparation methods described in claims 1 to 4.

6. The application of the carboxyl-modified organosilicon polymer of claim 5 in the preparation of coatings.

7. A coating, characterized in that, The components include the following parts by weight: 100 parts of the carboxyl-modified organosilicon polymer according to claim 5 Photoinitiator 0.5 to 3 parts.

8. The coating according to claim 7, characterized in that, The coating also includes 11 to 18 parts of a neutralizing agent.

9. A method of applying a coating, characterized in that, The coating described in any one of claims 7 to 8 is then photocured to form a coating layer.

10. The application of the coating according to any one of claims 7 to 8 in the field of biomedical device coatings.

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