A high-transparency biocompatible material for endoscopic-assisted water bags and its preparation method

Abstract

This invention relates to the field of silicone rubber materials technology, and discloses a high-transparency biocompatible material for endoscope-assisted water bags and its preparation method. The raw materials for this invention's high-transparency biocompatible material for endoscope-assisted water bags include 80-90 parts by weight of α,ω-dihydroxypolydimethylsiloxane, 10-20 parts by weight of silanol polylactic acid, and 0.04-0.07 parts by weight of catalyst, etc. This invention uses non-toxic and non-irritating silicone rubber and highly biocompatible polylactic acid as the matrix, which is non-irritating to the human body. The prepared material is suitable for use in medical devices such as endoscope-assisted water bags. The improved interfacial properties and compatibility between polylactic acid and α,ω-dihydroxypolydimethylsiloxane reduce the likelihood of interfacial defects, maintaining good light transmittance, tensile strength, and elongation at break. When used as an endoscope-assisted water bag, it allows for better observation, and polylactic acid imparts good biodegradability to the silicone rubber material.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber materials technology, specifically to a high-transparency biocompatible material for endoscope-assisted water bags and its preparation method. Background Technology

[0002] Silicone rubber, with its high chemical inertness, low surface energy, and low protein adsorption, is non-toxic, non-irritating, and biocompatible, making it widely used in implantable medical devices, infusion tubing, endoscopic assist water balloons, pneumatic balloons, and other medical supplies and in tissue engineering. Endoscopic assist water balloons are disposable medical elastic membrane sleeves attached to the tip of an endoscopic ultrasound probe. They inflate after being injected with saline solution and are an essential coupling accessory for intracavitary ultrasound imaging. The water balloon is required to have good transparency and structural stability. Furthermore, as a disposable medical device, improving its biodegradability can reduce medical waste pollution.

[0003] Polylactic acid (PLA) is an environmentally friendly material with high biocompatibility and biodegradability, and it also possesses good mechanical strength and structural stability, making it important for applications in medical devices and tissue engineering. Patent CN106009680B discloses a silicone rubber / PLA thermoplastic vulcanizate and its preparation method. Through a synergistic compatibilization system, the interfacial interaction between PLA and silicone rubber is improved, resulting in a silicone rubber-PLA thermoplastic vulcanizate with excellent mechanical properties and gas barrier properties. However, this patented thermoplastic vulcanizate does not exhibit high light transmittance, which is detrimental to the practical application of silicone rubber in fields such as endoscopic water bags. Summary of the Invention

[0004] This invention solves the problems of low mechanical properties and difficulty in biodegradation of silicone rubber materials.

[0005] The technical solution of the present invention is: a high-transparency biocompatible material, the raw materials of which include 80-90 parts by weight of α,ω-dihydroxypolydimethylsiloxane, 10-20 parts by weight of silanol polylactic acid, 2.8-4.6 parts by weight of plasticizer, 0.04-0.07 parts by weight of catalyst, 3-8 parts by weight of crosslinking agent, and 0.5-0.7 parts by weight of coupling agent;

[0006] Furthermore, the catalyst includes dibutyltin dilaurate; the plasticizer is dimethyl silicone oil.

[0007] Furthermore, the crosslinking agent includes methyltributanone oxime silane and vinyltributanone oxime silane.

[0008] Furthermore, the coupling agents include γ-aminopropyltriethoxysilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

[0009] Furthermore, the preparation method of polylactic acid with silanol is as follows:

[0010] (1) Add dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4-4.6 parts by weight of triethylamine, add 2.6-3 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 15-35℃ for 12-18h, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0011] (2) Add 1,4-dioxane and 100 parts by weight of acrylate polylactic acid to the reaction vessel, heat and stir to dissolve, purge with nitrogen, add 2.8-3.5 parts by weight of chlorosilane compound and 0.007-0.008 parts by weight of caster catalyst, heat to 80-95℃, stir and react for 4-6 hours, filter, add water to the filtrate, stir and hydrolyze for 4 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid. The reaction formula is:

[0012] .

[0013] Furthermore, the chlorosilane compound is dichloromethylsilane or trichlorosilane.

[0014] Furthermore, the preparation method of the high-transparency biocompatible material is characterized in that the preparation method is as follows: α,ω-dihydroxy polydimethylsiloxane, silanol polylactic acid, and plasticizer are added to a stirrer and stirred and mixed; a catalyst, crosslinking agent, and coupling agent are added and stirred and mixed; the mixture is poured into a mold and vulcanized at 15-40°C for 3-7 days to obtain the high-transparency biocompatible material.

[0015] Furthermore, highly transparent biocompatible materials are applied to endoscopy-assisted water bags.

[0016] The beneficial technical effects of this invention are as follows: Acryloyl chloride undergoes an esterification reaction with the terminal hydroxyl groups of polylactic acid (PLA), followed by an addition reaction between the alkenyl group and chlorosilane compounds such as trichlorosilane. Si-Cl hydrolyzes to generate Si-OH, thereby introducing a large amount of Si-OH at the terminal positions of PLA, yielding silanol-hydroxy PLA. Finally, it is mixed and vulcanized with α,ω-dihydroxypolydimethylsiloxane, a catalyst, and a crosslinking agent to obtain a highly transparent, biocompatible silicone rubber material. Using non-toxic and non-irritating silicone rubber and highly biocompatible PLA as the matrix, it is non-irritating to the human body, and the prepared material can be used in medical devices such as endoscopic assistive water bags.

[0017] The polylactic acid (PLA) of this invention contains multiple Si-OH bonds at its terminal positions. During vulcanization, it can undergo a condensation crosslinking reaction with the terminal Si-OH bonds of α,ω-dihydroxypolydimethylsiloxane, significantly enhancing the interfacial properties between PLA and α,ω-dihydroxypolydimethylsiloxane. This improves their compatibility, reduces the likelihood of interfacial defects, and maintains excellent light transmittance, tensile strength, and elongation at break. When used as an endoscope-assisted water bag, it allows for better observation while maintaining good structural stability, reducing the problem of deformation and shaking of the water bag that hinders observation. Furthermore, PLA imparts good biodegradability to silicone rubber materials, making it environmentally friendly. Attached Figure Description

[0018] Figure 1 This is the infrared spectrum of polylactic acid with hydroxyl groups from Example 1. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to specific examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] The following products are listed: α,ω-dihydroxypolydimethylsiloxane (CAS No. 70131-67-8), manufactured by Jiangsu Bost Chemical Co., Ltd.; dimethyl silicone oil (CAS No. 9006-65-9), manufactured by Jiangsu Bost Chemical Co., Ltd.; polylactic acid (average molecular weight 5500, 99% purity), manufactured by Qingdao Taihai Rui Biotechnology Co., Ltd.; and castor catalyst (Pt content 3000ppm), manufactured by Shanghai Neutron Star Chemical Technology Co., Ltd.

[0021] Example 1:

[0022] (1) Add 800 parts by weight of dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4.2 parts by weight of triethylamine, add 2.7 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 25°C for 18 hours, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0023] (2) Add 1200 parts by weight of 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 85°C, stir to dissolve, introduce nitrogen gas, add 3.2 parts by weight of trichlorosilane and 0.008 parts by weight of caster catalyst, continue stirring to react for 4 hours, filter, add water to the filtrate, stir to hydrolyze for 4 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid. Figure 1In the infrared spectrum, the ester group of polylactic acid with silanol groups is located at 1731 cm⁻¹. -1 At this location, Si-OH is located at 3296 cm⁻¹. -1 Place.

[0024] (3) Add 90 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 10 parts by weight of silanol polylactic acid, and 3.3 parts by weight of dimethyl silicone oil to a stirrer, heat to 80°C, stir and mix for 20 min, cool and then add 0.05 parts by weight of dibutyltin dilaurate, 3.5 parts by weight of methyl tributanone oxime silane, 0.5 parts by weight of vinyl tributanone oxime silane, and 0.6 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a high-transparency biocompatible material.

[0025] Example 2:

[0026] (1) Add 900 parts by weight of dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4.6 parts by weight of triethylamine, add 2.6 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 20°C for 18 hours, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0027] (2) Add 1300 parts by weight of 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 90°C, stir to dissolve, introduce nitrogen gas, add 3.5 parts by weight of methyldichlorosilane and 0.008 parts by weight of caster catalyst, continue stirring for 4 hours, filter, add water to the filtrate, stir and hydrolyze for 4 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid.

[0028] (3) Add 87.5 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 12.5 parts by weight of silanol polylactic acid, and 4 parts by weight of dimethyl silicone oil to a stirrer, heat to 80°C, stir and mix for 20 min, cool, add 0.04 parts by weight of dibutyltin dilaurate, 7 parts by weight of methyl tributanone oxime silane, 1 part by weight of vinyl tributanone oxime silane, and 0.5 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a high-transparency biocompatible material.

[0029] Example 3:

[0030] (1) Add 900 parts by weight of dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4.4 parts by weight of triethylamine, add 3 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 20°C for 18 hours, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0031] (2) Add 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 80°C, stir to dissolve, introduce nitrogen gas, add 2.8 parts by weight of trichlorosilane and 0.007 parts by weight of caster catalyst, continue stirring for 6 hours, filter, add water to the filtrate, stir and hydrolyze for 3 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid.

[0032] (3) Add 85 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 15 parts by weight of silanol polylactic acid, and 2.8 parts by weight of dimethyl silicone oil to a stirrer, heat to 90°C, stir and mix for 10 min, cool and then add 0.07 parts by weight of dibutyltin dilaurate, 2.7 parts by weight of methyl tributanone oxime silane, 0.3 parts by weight of vinyl tributanone oxime silane, and 0.7 parts by weight of γ-aminopropyltriethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a high-transparency biocompatible material.

[0033] Example 4:

[0034] (1) Add 900 parts by weight of dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4 parts by weight of triethylamine, add 2.7 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 25°C for 12 hours, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0035] (2) Add 1300 parts by weight of 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 95°C, stir to dissolve, introduce nitrogen gas, add 3 parts by weight of trichlorosilane and 0.008 parts by weight of caster catalyst, continue stirring to react for 4 hours, filter, add water to the filtrate, stir to hydrolyze for 3 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid.

[0036] (3) Add 82.5 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 12.5 parts by weight of silanol polylactic acid, and 4 parts by weight of dimethyl silicone oil to a stirrer, heat to 90°C, stir and mix for 15 min, cool, add 0.04 parts by weight of dibutyltin dilaurate, 5.4 parts by weight of methyl tributanone oxime silane, 0.6 parts by weight of vinyl tributanone oxime silane, and 0.6 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a high-transparency biocompatible material.

[0037] Example 5:

[0038] (1) Add 800 parts by weight of dichloromethane and 100 parts by weight of polylactic acid to the reaction vessel, stir to dissolve, add 4.2 parts by weight of triethylamine, add 2.9 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 25°C for 12 hours, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate with water and ethanol, dry, and obtain acrylate polylactic acid.

[0039] (2) Add 1200 parts by weight of 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 95°C, stir to dissolve, introduce nitrogen gas, add 3.2 parts by weight of trichlorosilane and 0.007 parts by weight of caster catalyst, continue stirring for 5 hours, filter, add water to the filtrate, stir and hydrolyze for 4 hours, filter, wash the precipitate with water and ethanol, dry, and obtain silanol polylactic acid.

[0040] (3) Add 80 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 20 parts by weight of silanol polylactic acid, and 4.6 parts by weight of dimethyl silicone oil to a stirrer, heat to 90°C, stir and mix for 15 min, cool and then add 0.06 parts by weight of dibutyltin dilaurate, 5.2 parts by weight of methyl tributanone oxime silane, 0.8 parts by weight of vinyl tributanone oxime silane, and 0.5 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a high-transparency biocompatible material.

[0041] Comparative Example 1 differs from Example 1 in that polylactic acid is used instead of silicone hydroxyl polylactic acid.

[0042] (1) Add 90 parts by weight of α,ω-dihydroxypolydimethylsiloxane, 10 parts by weight of polylactic acid, and 3.3 parts by weight of dimethyl silicone oil to a stirrer, heat to 80°C, stir and mix for 20 min, cool and then add 0.05 parts by weight of dibutyltin dilaurate, 3.5 parts by weight of methyl tributanone oxime silane, 0.5 parts by weight of vinyl tributanone oxime silane, and 0.6 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a biocompatible material.

[0043] Comparative Example 2 differs from Example 1 in that it uses acrylate polylactic acid instead of silicone hydroxyl polylactic acid.

[0044] (1) Add 90 parts by weight of α,ω-dihydroxypolydimethylsiloxane, 10 parts by weight of polylactic acid acrylate, and 3.3 parts by weight of dimethyl silicone oil to a stirrer, heat to 80°C, stir and mix for 20 min, cool and then add 0.05 parts by weight of dibutyltin dilaurate, 3.5 parts by weight of methyl tributanone oxime silane, 0.5 parts by weight of vinyl tributanone oxime silane, and 0.6 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a biocompatible material.

[0045] Comparative Example 3: The difference from Example 1 is that dimethylchlorosilane is used instead of trichlorosilane.

[0046] (1) Add 1200 parts by weight of 1,4-dioxane and 100 parts by weight of polylactic acid acrylate to a reaction vessel equipped with a reflux condenser. Heat to 85°C, stir to dissolve, introduce nitrogen gas, add 3.2 parts by weight of dimethylchlorosilane and 0.008 parts by weight of caster catalyst, continue stirring to react for 4 hours, filter, add water to the filtrate, stir to hydrolyze for 4 hours, filter, wash the precipitate with water and ethanol, dry to obtain polylactic acid hydroxyl.

[0047] (2) Add 90 parts by weight of α,ω-dihydroxy polydimethylsiloxane, 10 parts by weight of silanol polylactic acid, and 3.3 parts by weight of dimethyl silicone oil to a stirrer, heat to 80°C, stir and mix for 20 min, cool and then add 0.05 parts by weight of dibutyltin dilaurate, 3.5 parts by weight of methyl tributanone oxime silane, 0.5 parts by weight of vinyl tributanone oxime silane, and 0.6 parts by weight of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, stir and mix, pour into a mold, and vulcanize at 25°C for 7 days to obtain a biocompatible material.

[0048] Biocompatible materials were fabricated into circular discs with a diameter of 50 mm and a thickness of 0.15 mm. The total transmitted light flux T2 and incident light flux T1 of the biocompatible materials were measured using a haze meter. The test temperature was 23℃ and the relative humidity was 50%. The transmittance t was calculated as t = T2 / T1 × 100%.

[0049] Tensile properties were tested according to GB / T 528-2009 standard.

[0050] Biodegradability was tested according to GB / T 19277.1-2025 standard, and the degradation time was 90 days.

[0051] Table 1 Performance Tests

[0052]

[0053] In Comparative Example 1, polylactic acid (PLA) and α,ω-dihydroxypolydimethylsiloxane (PDMS) showed poor compatibility, easily leading to interfacial defects that affected the light transmittance and mechanical properties of the silicone rubber material, resulting in low transmittance, tensile strength, and elongation at break. In contrast, the silanol-hydroxy PLA of each embodiment contained multiple Si-OH bonds at their terminal sites. During vulcanization, these bonds could undergo condensation crosslinking with the terminal Si-OH bonds of α,ω-dihydroxypolydimethylsiloxane, significantly enhancing the interfacial properties between PLA and α,ω-dihydroxypolydimethylsiloxane. This improved compatibility reduced the likelihood of interfacial defects, allowing the material to maintain good light transmittance, tensile strength, and elongation at break. Furthermore, PLA imparted good biodegradability to the silicone rubber material.

[0054] Comparative Example 2's acrylate polylactic acid does not contain Si-OH bonds and cannot undergo cross-linking condensation reaction with the terminal Si-OH bonds of α,ω-dihydroxypolydimethylsiloxane. The compatibility between the two is very poor, resulting in low transmittance, tensile strength, and elongation at break of the silicone rubber material.

[0055] The silanol polylactic acid in Comparative Example 3 has fewer terminal Si-OH bonds and fewer reaction sites with α,ω-dihydroxypolydimethylsiloxane, which is not conducive to promoting the condensation crosslinking reaction between the two, resulting in lower transmittance, tensile strength and elongation at break of the silicone rubber material.

[0056] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A highly transparent biocompatible material, characterized in that, The raw materials for the high-transparency biocompatible material used in the endoscopic-assisted water bag include 80-90 parts by weight of α,ω-dihydroxypolydimethylsiloxane, 10-20 parts by weight of silanol polylactic acid, 2.8-4.6 parts by weight of plasticizer, 0.04-0.07 parts by weight of catalyst, 3-8 parts by weight of crosslinking agent, and 0.5-0.7 parts by weight of coupling agent; The preparation method of the silanol polylactic acid is as follows: 1,4-dioxane and acrylate polylactic acid are added to a reaction vessel, heated and stirred to dissolve, nitrogen gas is introduced, chlorosilane compound and caster catalyst are added, the reaction is carried out, water is added to the filtrate after filtration, the mixture is stirred to hydrolyze, filtered, the precipitate is washed, and dried to obtain silanol polylactic acid.

2. The high-transparency biocompatible material according to claim 1, characterized in that, The catalyst is dibutyltin dilaurate; the plasticizer is dimethyl silicone oil.

3. The high-transparency biocompatible material for endoscopic-assisted water bags according to claim 1, characterized in that, The crosslinking agent is one or more of methyltributanone oxime silane and vinyltributanone oxime silane.

4. The high-transparency biocompatible material according to claim 1, characterized in that, The coupling agent is one or more of γ-aminopropyltriethoxysilane and N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane.

5. The high-transparency biocompatible material according to claim 1, characterized in that, The amount of polylactic acid acrylate is 100 parts by weight, the amount of chlorosilane compound is 2.8-3.5 parts by weight, and the amount of caster catalyst is 0.007-0.008 parts by weight.

6. The high-transparency biocompatible material according to claim 1, characterized in that, The chlorosilane compound is dichloromethylsilane or trichlorosilane.

7. The high-transparency biocompatible material according to claim 1, characterized in that, The reaction temperature is 80-95℃, and the reaction time is 4-6 hours.

8. The high-transparency biocompatible material according to claim 5, characterized in that, The preparation method of the acrylate polylactic acid is as follows: add dichloromethane and 100 parts by weight of polylactic acid to a reaction vessel, stir to dissolve, add 4-4.6 parts by weight of triethylamine, add 2.6-3 parts by weight of acryloyl chloride dropwise in an ice-water bath, stir and react at 15-35℃ for 12-18h, filter, add ethanol to the filtrate to precipitate, filter, wash the precipitate, dry, and obtain acrylate polylactic acid.

9. A method for preparing a high-transparency biocompatible material as described in any one of claims 1-8, characterized in that, The preparation method is as follows: α,ω-dihydroxy polydimethylsiloxane, silanol polylactic acid, and plasticizer are added to a stirrer, heated and stirred to mix, and after cooling, catalyst, crosslinking agent, and coupling agent are added, stirred and mixed, poured into a mold, and vulcanized at 15-40℃ for 3-7 days to obtain a highly transparent biocompatible material.

10. The application of a highly transparent biocompatible material obtained by the preparation method as described in claim 9 in an endoscopy-assisted water bag.

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