阅读说明：本技术 一种基于丙烯酸类聚合和光固化的亲水涂层及其制备方法 (Hydrophilic coating based on acrylic polymerization and photocuring and preparation method thereof ) 是由 钱善华 周帅帅 陈惟惟 卞达 倪自丰 于 2021-09-18 设计创作，主要内容包括：本发明公开了一种基于丙烯酸类聚合和光固化的亲水涂层及其制备方法,属于材料表面处理技术领域。本发明所述的制备亲水涂层的方法,包括如下步骤：(1)将基材浸渍在预处理溶液中,取出,干燥,得到预处理的基材；(2)将丙烯酸类单体、交联剂、光引发剂、亲水性大分子、丙三醇和水混合均匀,得到亲水溶液；(3)将步骤(1)得到的预处理的基材浸渍在步骤(2)的亲水溶液中,浸渍的同时在紫外灯下固化,取出,清洗,得到含有亲水涂层的基材。本发明的亲水涂层具有优异的结合强度和亲水性,且在体液环境中表现出超低的摩擦系数,且工艺简单,对环境和设备要求低。(The invention discloses a hydrophilic coating based on acrylic polymerization and photocuring and a preparation method thereof, and belongs to the technical field of material surface treatment. The method for preparing the hydrophilic coating comprises the following steps: (1) dipping the base material in the pretreatment solution, taking out and drying to obtain a pretreated base material; (2) uniformly mixing an acrylic monomer, a cross-linking agent, a photoinitiator, hydrophilic macromolecules, glycerol and water to obtain a hydrophilic solution; (3) and (3) dipping the pretreated base material obtained in the step (1) in the hydrophilic solution obtained in the step (2), curing under an ultraviolet lamp while dipping, taking out, and cleaning to obtain the base material containing the hydrophilic coating. The hydrophilic coating has excellent bonding strength and hydrophilicity, shows an ultra-low friction coefficient in a body fluid environment, and has simple process and low requirements on environment and equipment.)

1. A method of making a hydrophilic coating comprising the steps of:

(1) dipping the base material in the pretreatment solution, taking out and drying to obtain a pretreated base material;

(2) uniformly mixing an acrylic monomer, a cross-linking agent, a photoinitiator, hydrophilic macromolecules, glycerol and water to obtain a hydrophilic solution;

(3) and (3) dipping the pretreated base material obtained in the step (1) in the hydrophilic solution obtained in the step (2), curing under an ultraviolet lamp while dipping, taking out, and cleaning to obtain the base material containing the hydrophilic coating.

2. The method according to claim 1, wherein the pretreatment solution in step (1) is a benzophenone solution with a mass concentration of 1-10%.

3. The method according to claim 1 or 2, wherein the acrylic monomer in step (2) is one or more of hydroxyethyl methacrylate, acrylamide and butyl acrylate.

4. The method according to any one of claims 1 to 3, wherein the mass concentrations of the acrylic monomer, the crosslinking agent, the photoinitiator, the hydrophilic macromolecule and the glycerol in the hydrophilic solution in the step (2) are respectively 5% to 20%, 0.5% to 2%, 0.1% to 1%, 1% to 10%, 20% to 40%, and the balance is water.

5. The method according to any one of claims 1 to 4, wherein the UV curing in step (3) is performed for 10 to 30min under 365nm/100W UV lamp.

6. The method according to any one of claims 1 to 5, wherein the photoinitiator in the step (2) is a photoinitiator 2959.

7. The method according to any one of claims 1 to 6, wherein the crosslinking agent in step (2) is N, N' -methylenebisacrylamide.

8. The method according to any one of claims 1 to 7, wherein the hydrophilic macromolecule in step (2) is one of polyaspartic acid, xanthan gum and sodium alginate.

9. A substrate comprising a hydrophilic coating prepared by the method of any one of claims 1 to 8.

10. Use of a substrate comprising a hydrophilic coating according to claim 9 or a method of producing a hydrophilic coating according to any one of claims 1 to 8 for the hydrophilic modification of a surface of a medical device.

Technical Field

The invention relates to a hydrophilic coating based on acrylic polymerization and photocuring and a preparation method thereof, belonging to the technical field of material surface treatment.

Background

The silicon rubber has good mechanical property and chemical stability, and has wide application prospect in the field of biomedical instruments, such as common medical catheters, electronic gastroscope externally-wound tubes, microfluidic equipment and the like. However, the application of the silicon rubber material is limited by the hydrophobicity of the silicon rubber material, and when an appliance taking the silicon rubber as the main material is in contact with human tissues, the appliance can generate larger frictional resistance to cause certain damage to the human tissues. The surface of the silicon rubber is subjected to hydrophilic modification, so that the hydrophilicity of the material can be effectively improved, the frictional resistance between an instrument and a tissue is reduced, and the comfort of a patient is improved.

At present, the acquisition of a hydrophilic surface for hydrophobic materials can be carried out in two steps: firstly, the surface of a hydrophobic material needs to be pretreated, so that the wettability of the surface of the material is improved; then coating or grafting hydrophilic substances on the treated surface so as to achieve the purpose of changing the surface wettability of the material; wherein the pretreatment is generally to directly plasma treat the surface to obtain the hydrophilic property in a short period.

Disclosure of Invention

[ problem ] to

Although hydrophilic surfaces can be obtained by deposition or brush grafting of polymers for hydrophilic coatings, certain disadvantages remain, such as: the hydrophilic coating prepared by the graft polymer brush method is usually only nano-scale in thickness, and the coating is fragile and easy to break; the hydrophilic coating prepared by the deposition method is long in preparation period, and the deposited coating is easy to fall off and poor in hydrophilic persistence. Therefore, it is very important to find a method for preparing a hydrophilic coating with simplicity, short period and remarkable effect.

[ solution ]

In order to solve at least one problem, the invention provides a preparation method of a hydrophilic coating based on acrylic polymerization and photocuring, which comprises the steps of firstly dipping an initiator solution, then immersing a sample in a monomer solution and placing the monomer solution for curing under ultraviolet rays, and finally cleaning an uncrosslinked product to obtain the hydrophilic coating; the hydrophilic coating has excellent bonding strength and hydrophilicity, shows an ultra-low friction coefficient in a body fluid environment, and has simple process and low requirements on environment and equipment.

It is a first object of the present invention to provide a method for preparing a hydrophilic coating, comprising the steps of:

(1) dipping the base material in the pretreatment solution, taking out and drying to obtain a pretreated base material;

(2) uniformly mixing an acrylic monomer, a cross-linking agent, a photoinitiator, hydrophilic macromolecules, glycerol and water to obtain a hydrophilic solution;

(3) and (3) dipping the pretreated base material obtained in the step (1) in the hydrophilic solution obtained in the step (2), curing under an ultraviolet lamp while dipping, taking out, and cleaning to obtain the base material containing the hydrophilic coating.

In one embodiment of the present invention, the pretreatment solution in step (1) is a benzophenone solution, and the solvent of the benzophenone solution is absolute ethanol, and the mass concentration of the absolute ethanol is 1% to 10%.

In one embodiment of the present invention, the substrate in step (1) comprises RTV-silica gel, polydimethylsiloxane PDMS.

In an embodiment of the present invention, the dipping in step (1) is carried out at 20-30 ℃ (room temperature) for 2-10 min, and more preferably at 25 ℃ for 5 min.

In an embodiment of the present invention, the acrylic monomer in step (2) is one or more of hydroxyethyl methacrylate, acrylamide, and butyl acrylate.

In one embodiment of the present invention, the crosslinking agent in step (2) is N, N' -methylenebisacrylamide.

In one embodiment of the present invention, the photoinitiator in step (2) is photoinitiator 2959.

In an embodiment of the present invention, the hydrophilic macromolecule in step (2) is one of polyaspartic acid, xanthan gum and sodium alginate.

In one embodiment of the present invention, the mass concentrations of the acrylic monomer, the crosslinking agent, the photoinitiator, the hydrophilic macromolecule and the glycerol in the hydrophilic solution in the step (2) are 5% to 20%, 0.5% to 2%, 0.1% to 1%, 1% to 10%, 20% to 40%, respectively, and the balance is water.

In one embodiment of the present invention, the dipping in step (3) is carried out at 20-30 ℃ (room temperature) for 10-30 min.

In one embodiment of the present invention, the UV curing in step (3) is performed by irradiating with a 365nm/100W UV lamp for 10-30 min.

In one embodiment of the present invention, the cleaning in step (3) is ultrasonic cleaning with ethanol.

A second object of the invention is a substrate comprising a hydrophilic coating, prepared by the process according to the invention.

A third object of the present invention is the use of a substrate comprising a hydrophilic coating or a method for preparing a hydrophilic coating according to the present invention in the field of hydrophilic modification of the surface of a medical device.

[ advantageous effects ]

(1) The hydrophilic coating has excellent bonding strength and hydrophilicity, shows an ultra-low friction coefficient in a body fluid environment, and has simple process and low requirements on environment and equipment.

(2) The invention carries out hydrophilic modification mechanism on the silicon rubber; firstly, a silicon rubber matrix needs to be pretreated, the silicon rubber matrix is soaked in an organic solvent containing an initiator, and the initiator is permeated into the silicon rubber by utilizing the characteristic that the organic solvent can swell the silicon rubber, so that the surface of the silicon rubber has initiating activity; then, immersing the silicon rubber in the monomer solution, and curing for a period of time under ultraviolet light; the monomer solution comprises an acrylic monomer, a cross-linking agent, an initiator and hydrophilic macromolecules, in the curing process, the initiator penetrating into the silicon rubber initiates the polymerization of the monomer below the surface of the silicon rubber, the external initiator initiates the polymerization of the monomer above the surface of the silicon rubber, and the polymerized coating and the base material have overlapped parts in space, so that the problem that the coating falls off due to poor adhesion is avoided; and finally, only a product which is not crosslinked with the base material on the surface of the silicon rubber needs to be cleaned.

(3) The contact angle of the hydrophilic coating prepared by the invention is lower than 34.29 degrees, the roughness is lower than 0.74 mu m, the friction coefficient is 0.11-0.44, and compared with the original base material (silicon rubber sheet, the friction coefficient is 2.16), the friction coefficient is reduced by 79.63% -94.91%.

Drawings

FIG. 1 shows the contact angle test results of the silicone rubber sheet containing a hydrophilic coating of example 1.

Figure 2 is a surface image of the coating of the silicone rubber sheet containing the hydrophilic coating of example 1.

FIG. 3 is a friction coefficient test of the silicone rubber sheet containing a hydrophilic coating of example 1.

Fig. 4 is a surface image of a silicone rubber sheet containing a hydrophilic coating prepared in comparative example 5.

FIG. 5 is a surface contact angle of a silicone rubber sheet containing a hydrophilic coating prepared in comparative example 6, wherein A is no polyaspartic acid added; b is the addition of polyaspartic acid.

FIG. 6 is a surface image of a silicone rubber sheet containing a hydrophilic coating prepared in comparative example 7; wherein A is no added glycerol; and B is the additive of glycerol.

Detailed Description

The following description of the preferred embodiments of the present invention is provided for the purpose of better illustrating the invention and is not intended to limit the invention thereto.

The test method comprises the following steps:

testing of contact Angle:

deionized water was used as the test liquid, and the test was carried out by using a contact angle measuring instrument (JC2000CS, China), with a test droplet of 2. mu.L and a spreading time of 30 s. Each sample was randomly tested at 3 positions and the results averaged.

Testing of the coefficient of friction:

the test was carried out using a multifunctional friction wear tester (MFT-5000, USA) rotating module. PDMS disc and 12mm silica gel ball as friction pair, wherein the coating preparation in PDMS disc. The test lubricating medium is pure water, the set loading pressure is 0.5N, the rotating speed is 60r/min, the rotating radius is 10mm, and each sample is tested for 3 times and each time is tested for 3 min.

Testing surface appearance and roughness:

white light interference/atomic force dual mode microscopy (MFP-D, USA) was used to obtain surface topography images and surface roughness of the coatings. Each sample was randomly tested at 3 positions and the roughness results averaged.

Example 1

A method of making a hydrophilic coating comprising the steps of:

(1) placing a silicon rubber sheet (PDMS) cut to be 10mm multiplied by 3mm in absolute ethyl alcohol, ultrasonically cleaning for 5min, and airing to obtain a cleaned silicon rubber sheet;

(2) dissolving 0.5g of benzophenone in 9.5g of absolute ethyl alcohol to obtain a pretreatment solution; dipping the silicon rubber sheet obtained in the step (1) in a pretreatment solution at normal temperature of 25 ℃ for 5min, taking out and drying to obtain a pretreated silicon rubber sheet;

(3) 1g of hydroxyethyl methacrylate, 0.2g N, N' -methylenebisacrylamide, 0.2g of photoinitiator 2959, 0.8g of polyaspartic acid and 8g of glycerol are dissolved in 9.8g of deionized water in sequence to obtain a hydrophilic solution;

(4) placing the pretreated silicon rubber sheet obtained in the step (2) in the hydrophilic solution obtained in the step (3), soaking at 25 ℃, simultaneously placing under a 365nm/100W ultraviolet lamp for 10cm, irradiating for 20min, and performing ultraviolet curing; and taking out after curing is finished, removing residual reaction products on the surface, and then placing the silicon rubber sheet in absolute ethyl alcohol for ultrasonic cleaning for 5min to obtain the silicon rubber sheet containing the hydrophilic coating.

The silicone rubber sheet with the hydrophilic coating obtained was subjected to a performance test, and the test results are shown in fig. 1.

Fig. 1 to 3 are performance tests of the silicone rubber sheet containing the hydrophilic coating of example 1. As can be seen from fig. 1: compared with a hydrophobic substrate silicone rubber sheet (contact angle of 98.39 degrees), the contact angle of the surface of the silicone rubber sheet containing the hydrophilic coating is 34.29 degrees, and excellent hydrophilic performance is shown; as can be seen from fig. 2, the surface of the coating is relatively flat, and the coating shows good surface quality; as can be seen from fig. 3, the friction coefficient of the coating surface is as low as 0.11, and the coating greatly improves the lubricating property of the coating surface compared to the larger friction coefficient of PDMS (2.16).

Comparative example 1

Benzophenone in the pretreatment solution of step (2) of example 1 was adjusted to be a photoinitiator 1173 and a photoinitiator 2959, while glycerol in step (3) was omitted, and the amount of water was adjusted to 17.8g to ensure that the total amount of the hydrophilic solution was 20g, and the balance was the same as that of example 1, to obtain a silicone rubber sheet having a hydrophilic coating.

Comparative example 2

Benzophenone in the pretreatment solution of the step (2) of example 1 was omitted and glycerin in the step (3) was omitted, and the amount of water was adjusted to 17.8g to ensure that the total amount of the hydrophilic solution was 20g, and otherwise the same as that of example 1 was maintained, to obtain a silicone rubber sheet having a hydrophilic coating.

The silicone rubber sheets containing a hydrophilic coating obtained in comparative examples 1 and 2 were subjected to a performance test, and the test results were as follows:

as can be seen from table 1: when the photoinitiator is not added and the photoinitiator 2959 is used for treating the silicon rubber, the coating cannot be attached to the surface of the base material, and the preparation of the coating fails; when the photoinitiator 1173 is used for treating the silicon rubber, the coating has poor hydrophilicity; when benzophenone is used, the coating has excellent hydrophilic properties.

TABLE 1 Effect of different types of pretreatment solutions on coating contact Angle

Type of initiator	Benzophenones as fungicides	Without addition of initiator (control 2)	Photoinitiator 1173	Photoinitiator 2959
					Contact angle (°)	8.64	＞90	65.00	＞90

Comparative example 3

The photoinitiator 2959 in step (3) of example 1 was adjusted to be the initiator 1173, while the glycerol in step (3) was omitted, and the amount of water was adjusted to 17.8g to ensure that the total amount of the hydrophilic solution was 20g, and otherwise, the same as example 1 was maintained, to obtain a silicone rubber sheet having a hydrophilic coating.

Comparative example 4

The photoinitiator 2959 in step (3) of example 1 was omitted, the glycerol in step (3) was also omitted, the amount of water was adjusted to 18g, and the total amount of the hydrophilic solution was 20g, and the balance was the same as that in example 1, to obtain a silicone rubber sheet having a hydrophilic coating.

The obtained silicone rubber sheet containing the hydrophilic coating was subjected to a hydrophilic property test, and the test results are shown in table 2:

as can be seen from table 2: when the photoinitiator is not added into the hydrophilic solution, the monomer cannot be polymerized on the surface of the base material, and the preparation of the coating fails; when the photoinitiator 1173 is used, the hydrophilicity of the coating surface is poor, and when the photoinitiator 2959 is used, the coating has excellent hydrophilic properties.

TABLE 2 Effect of different photoinitiators on coating contact Angle

Type of initiator	Photoinitiator 2959	Photoinitiator 1173 (control 3)	Without addition of initiator (comparative example 4)
				Contact angle (°)	8.64	52.49	＞90

Comparative example 5

The crosslinking agent N, N' -methylenebisacrylamide in the step (3) of example 1 was omitted, while the glycerin in the step (3) was omitted, and the amount of water was adjusted to 18g to ensure that the total amount of the hydrophilic solution was 20g, and otherwise, the same as in example 1 was maintained, to obtain a silicone rubber sheet having a hydrophilic coating.

The surface topography of the resulting hydrophilic coating is shown in fig. 4:

as can be seen from fig. 4: obvious cracks appear on the surface of the coating when no cross-linking agent is added, the surface of the coating is hard and brittle and can be easily broken, and the mechanical property of the coating is not matched with that of the base material.

Comparative example 6

The polyaspartic acid in step (3) of example 1 was omitted, the glycerin in step (3) was omitted, and the amount of water was adjusted to 18.6g to ensure that the total amount of the hydrophilic solution was 20g, and otherwise the hydrophilic coating-containing silicone rubber sheet was obtained in accordance with example 1.

The obtained silicone rubber sheet with the hydrophilic coating was subjected to a hydrophilic property test, and the test results are shown in fig. 5:

as can be seen from fig. 5: the contact angle of the coating was 63.92 ° without polyaspartic acid addition and decreased to 10.29 ° when polyaspartic acid was added, indicating that polyaspartic acid addition can increase the hydrophilicity of the coating.

Comparative example 7

The glycerol in the step (3) of example 1 was omitted, and the amount of water was adjusted to 17.8g to ensure that the total amount of the hydrophilic solution was 20g, and the balance was the same as that of example 1, to obtain a silicone rubber sheet having a hydrophilic coating.

The obtained silicone rubber sheet containing the hydrophilic coating was subjected to surface topography test, and the test results are shown in fig. 6:

as can be seen from fig. 6: when no glycerol is added, the surface of the coating presents a uniform rough structure. When the glycerol is added, the rough structure of the surface of the coating disappears, and the surface of the coating is relatively flat, which shows that the glycerol can improve the surface quality of the coating to a certain extent.

Example 2

The amount of glycerol used in step (3) of example 1 was adjusted to 0, 2, 4, 6, 8, 10g, while the amount of water used was adjusted to 17.8, 15.8, 13.8, 11.8, 9.8, 7.8g, to ensure that the total amount of hydrophilic solution was 20g, and otherwise the same as in example 1, to obtain a silicone rubber sheet having a hydrophilic coating.

The silicone rubber sheets containing the hydrophilic coating obtained were tested and the results are given in table 3 below:

as can be seen from table 3: with the increase of the content of the glycerol, the friction coefficient is firstly reduced and then increased, and when the dosage is 8g, the friction coefficient is the minimum and is 0.11; as the content of glycerin increases, the contact angle gradually increases and the roughness gradually decreases.

TABLE 3 Effect of different Glycerol contents on coating Properties

Content of Glycerol (g)	Coefficient of friction	Contact angle (°)	Roughness (μm)
				0	0.86	9.39	2.12
2	0.67	13.95	1.25
				4	0.44	17.62	0.74
6	0.31	23.34	0.29
				8 (example 1)	0.11	34.29	0.05
10	0.47	49.08	0.03

Although the present invention has been described with reference to the preferred embodiments, it should be understood that various changes and modifications can be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.