Silicon ester-based flexible vulcanizable material and method for preparing the same

Abstract

The present application relates to the technical field of high polymer materials, and particularly relates to a silicate-based flexible vulcanizable material and a preparation method thereof, which comprises, by mass fraction, 60-80 parts of silicone rubber, 25-35 parts of polyurethane, 5-15 parts of organic solvent, 3-8 parts of softener, 0.5-1.5 parts of coupling agent, 0.1-0.5 parts of crosslinking agent, 5-15 parts of reinforcing carbon black, 0.2-1 parts of polyhydric alcohol, 0.1-0.3 parts of chitosan and 0.5-1.5 parts of t-butyl peroxy phthalate. The silicate-based flexible vulcanizable material prepared by using the formula of the present application has excellent performance in wrinkle resistance, breaking strength, elongation at break, tear strength and bonding performance, and can meet the use requirements of vortex-induced vibration suppression towrope-kite type products.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a silicone ester-based flexible vulcanizable material and its preparation method. Background Technology

[0002] Silicone rubber and polyurethane are two common polymer materials. Silicone rubber has excellent weather resistance, insulation and physiological inertness, while polyurethane has high strength, high elasticity and high wear resistance. However, their limitations are also very obvious.

[0003] There is a wealth of literature available on the blending modification of silicone rubber and polyurethane materials. These studies primarily focus on laboratory-level research, examining aspects such as interfacial tension, mechanical properties, and biocompatibility after blending modification. However, there is a lack of research addressing industrial applications, such as tear strength, flexibility and wrinkle resistance, high-temperature and UV resistance, chemical adhesion, and mass production challenges.

[0004] During the research and production of vortex-induced vibration damping drag cables (ribbon type), problems were encountered regarding the poor wrinkle resistance of polyurethane and the poor strength and chemical adhesion of silicone rubber. Therefore, it is necessary to develop a silicone rubber-polyurethane blend modification material to meet the requirements of high strength, good toughness, recoverable wrinkle resistance, and chemical bonding. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a silicone-based flexible vulcanizable material and its preparation method.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] The first aspect of this invention provides a silicone-based flexible vulcanizable material, comprising, by weight: 60-80 parts silicone rubber, 25-35 parts polyurethane, 5-15 parts organic solvent, 3-8 parts softener, 0.5-1.5 parts coupling agent, 0.1-0.5 parts crosslinking agent, 5-15 parts reinforcing carbon black, 0.2-1 part polyol, 0.1-0.3 parts chitosan, and 0.5-1.5 parts tert-butyl phthalate peroxide.

[0008] Preferably, the organic solvent is any one of tetrahydrofuran, ethanol, and acetone.

[0009] Preferably, the softener is trioctyl phosphate and the coupling agent is tetrapropoxysilane.

[0010] Preferably, the crosslinking agent is a di(2,4)-di ...

[0011] This invention also provides a method for preparing a silicone-based flexible vulcanizable material, comprising the following steps:

[0012] Silicone rubber and crosslinking agent are mixed using a rubber mixing equipment, and reinforcing carbon black is added and mixed again to obtain the mixed silicone rubber.

[0013] Chitosan and tert-butyl phthalate peroxide are dispersed in an organic solvent and then coated onto the surface of the mixed silicone rubber. The silicone rubber is then irradiated with a UV lamp to obtain activated silicone rubber.

[0014] The activated silicone rubber, polyurethane, coupling agent and organic solvent are added to another rubber mixing equipment. After heating and the materials are completely melted, a softener is added and mixed to make sheets. After cooling, one side of the sheet is coated with polyol and placed in a pre-prepared weak alkaline water, with the side coated with polyol in contact with the water surface.

[0015] Finally, the material is vulcanized in a vulcanizing machine to obtain a silicone-based flexible vulcanizable material.

[0016] Preferably, the conditions for mixing the silicone rubber and crosslinking agent are: 50-100℃, 10-30min; and the conditions for adding reinforcing carbon black and continuing to mix are: 170-190℃, 3-10min.

[0017] Preferably, the irradiation time of the ultraviolet lamp is 1-5 minutes.

[0018] Preferably, the mixing conditions for adding fabric softener are: 120-200℃, 10-30min.

[0019] Preferably, the weak alkaline water is prepared by adding anhydrous sodium carbonate to pure water, adjusting the pH to 8, and adjusting the water temperature to 65℃-70℃.

[0020] Preferably, the vulcanization conditions are: 1-5 MPa, 50-100℃, 10 min.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The silicone-based flexible vulcanizable material prepared using the formula of this invention exhibits excellent performance in wrinkle resistance, tensile strength, elongation at break, tear strength, and adhesive properties, and can meet the usage requirements of vortex-induced vibration damping drag cable-ribbon type products.

[0023] 2. The formulation of this invention uses chitosan and tert-butyl phthalate peroxide, which produce a synergistic enhancing effect when added simultaneously. Attached Figure Description

[0024] Figure 1 This is a picture of a vortex-induced vibration damping cable-ribbon type product.

[0025] Figure 2This is a photograph of the ribbon obtained from the silicone-based flexible vulcanizable material in Example 1. Detailed Implementation

[0026] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0027] Among them, silicone rubber: Wacker R401 / 70A, Shanghai Yazhu Chemical Technology Co., Ltd.;

[0028] Polyurethane: IROGRANA 85P4394, Huntsman Chemical Trading (Shanghai) Co., Ltd.; Example 1

[0029] A silicone-based flexible vulcanizable material comprises, by weight: 70 parts silicone rubber, 30 parts polyurethane, 10 parts organic solvent, 5 parts softener, 1 part coupling agent, 0.3 parts crosslinking agent, 10 parts reinforcing carbon black, 0.5 parts polyol, 0.2 parts chitosan, and 1 part tert-butyl phthalate peroxide.

[0030] A method for preparing a silicone-based flexible vulcanizable material includes the following steps:

[0031] Silicone rubber and crosslinking agent are mixed using a rubber mixing equipment at 75°C for 20 minutes; reinforcing carbon black is added and mixing continues at 180°C for 5 minutes. After mixing, the material temperature is maintained at 35-40°C to obtain the mixed silicone rubber.

[0032] Chitosan and tert-butyl phthalate peroxide were dispersed in tetrahydrofuran and then coated onto the surface of the mixed silicone rubber. The silicone rubber was then irradiated with ultraviolet light for 3 minutes to obtain activated silicone rubber.

[0033] The activated silicone rubber, polyurethane, coupling agent, and tetrahydrofuran were added to another rubber mixing equipment. After the materials were completely melted, the softener was added and the mixture was mixed at 185°C for 20 minutes. The mixture was then made into a sheet with a thickness of 1 mm. The sheet was cooled to 70°C, and one side of the sheet was coated with ethylene glycol. The sheet was then placed in a pre-prepared weak alkaline solution (the weak alkaline solution is prepared by adding anhydrous sodium carbonate to pure water, adjusting the pH to 8, and adjusting the water temperature to 65°C-70°C). The side coated with ethylene glycol was in contact with the water surface.

[0034] Finally, the material is vulcanized in a vulcanizing machine under the following conditions: 3 MPa, 70°C, and 10 min, to obtain a silicone-based flexible vulcanizable material. Example 2

[0035] The difference between this embodiment and Embodiment 1 is that 60 parts are silicone rubber, while the rest are exactly the same as in Embodiment 1. Example 3

[0036] The difference between this embodiment and Embodiment 1 is that 80 parts are silicone rubber, while the rest are exactly the same as in Embodiment 1. Example 4

[0037] The difference between this embodiment and Embodiment 1 is that: 25 parts of polyurethane are used, while the rest of the components are exactly the same as in Embodiment 1. Example 5

[0038] The difference between this embodiment and Embodiment 1 is that: 35 parts of polyurethane are used, while the rest of the components are exactly the same as in Embodiment 1.

[0039] Comparative Example 1

[0040] The difference between this comparative example and Example 1 is that: there are 0 parts of chitosan, and the rest are exactly the same as in Example 1.

[0041] Comparative Example 2

[0042] The difference between this comparative example and Example 1 is that: 0 parts of tert-butyl phthalate peroxide, and the rest are exactly the same as in Example 1.

[0043] Comparative Example 3

[0044] The difference between this comparative example and Example 1 is that: 0 parts chitosan and 0 parts tert-butyl phthalate peroxide are used, while the rest are exactly the same as in Example 1.

[0045] Results and Detection

[0046] Wrinkle resistance: A pre-made film with a length and width of 300mm and a thickness of 1mm was folded in half and then pressed with a 1kg weight for 24 hours before being released. The recovery of the creases was then compared.

[0047] Breaking strength, elongation at break, and tear strength: tested according to GJB 1916A-2022.

[0048] Adhesion: The tear strength between the material and the vulcanizate in the cold vulcanized state was tested according to GJB 1916A-2022. The results are shown in Table 1.

[0049] Table 1

[0050]

[0051] As can be seen from Examples 1-5 in Table 1, the silicone-based flexible vulcanizable material prepared using the formulation of the present invention exhibits excellent performance in wrinkle resistance, breaking strength, elongation at break, tear strength, and adhesion, and can meet the usage requirements of vortex-induced vibration damping drag cable-ribbon type products.

[0052] Comparative Examples 1 and 1-3 show that the addition of chitosan and tert-butyl phthalate peroxide has a significant impact on the final performance of the product, such as adhesion. In Comparative Example 1, the adhesion is 38.4 N / mm when chitosan is absent and only tert-butyl phthalate peroxide is added; in Comparative Example 2, the adhesion is 33.2 N / mm when chitosan is absent and only chitosan is added; when both are absent, the adhesion decreases to 30.1 N / mm (Comparative Example 3); and when both are added, the adhesion increases to 48.6 N / mm (Example 1). This indicates that when both are added simultaneously, a synergistic enhancing effect is produced. The possible reason is that chitosan contains a large number of hydroxyl and amino groups, while tert-butyl phthalate peroxide contains carboxyl groups and oxidizing peroxy groups. When both are added at the same time, on the one hand, the surface roughness of silicone rubber is increased, and the van der Waals forces between molecules are enhanced. On the other hand, the film-forming ability of silicone rubber is improved. After blending with polyurethane and heating, the polyurethane melts rapidly. The ester groups, ether bonds and broken silicon-oxygen bonds form new chemical bonds under the combined action of coupling agents and organic solvents. The addition of softener interacts with the hydroxyl and carboxyl groups on the material surface to form very strong orientation and adsorption. Furthermore, the chemical adhesion properties of hydrophilic groups are further improved by coating with polyol.

[0053] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A silicone-based flexible vulcanizable material, characterized in that, The composition by weight is as follows: 60-80 parts silicone rubber, 25-35 parts polyurethane, 5-15 parts organic solvent, 3-8 parts softener, 0.5-1.5 parts coupling agent, 0.1-0.5 parts crosslinking agent, 5-15 parts reinforcing carbon black, 0.2-1 part polyol, 0.1-0.3 parts chitosan, and 0.5-1.5 parts tert-butyl phthalate peroxide; The preparation method of the aforementioned silicone-based flexible vulcanizable material includes the following steps: Silicone rubber and crosslinking agent are mixed using a rubber mixing equipment, and reinforcing carbon black is added and mixed again to obtain the mixed silicone rubber. Chitosan and tert-butyl phthalate peroxide are dispersed in an organic solvent and then coated onto the surface of the mixed silicone rubber. The silicone rubber is then irradiated with a UV lamp to obtain activated silicone rubber. The activated silicone rubber, polyurethane, coupling agent and organic solvent are added to another rubber mixing equipment. After heating and the materials are completely melted, a softener is added and mixed to make sheets. After cooling, one side of the sheet is coated with polyol and placed in a pre-prepared weak alkaline water, with the side coated with polyol in contact with the water surface. Finally, the material is vulcanized in a vulcanizing machine to obtain a silicone-based flexible vulcanizable material.

2. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The organic solvent is any one of tetrahydrofuran, ethanol, and acetone.

3. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The softener is trioctyl phosphate, and the coupling agent is tetrapropoxysilane.

4. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The crosslinking agent is a di(2,4)-di ...

5. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The conditions for mixing the silicone rubber and crosslinking agent are: 50-100℃, 10-30min; the conditions for adding reinforcing carbon black and continuing mixing are: 170-190℃, 3-10min.

6. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The UV lamp irradiation time is 1-5 minutes.

7. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The conditions for adding fabric softener and mixing are: 120-200℃, 10-30min.

8. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The method for preparing the weak alkaline water is as follows: add anhydrous sodium carbonate to pure water, adjust the pH to 8, and adjust the water temperature to 65℃-70℃.

9. The silicone-based flexible vulcanizable material according to claim 1, characterized in that, The conditions for the vulcanization treatment are: 1-5 MPa, 50-100℃, 10 min.

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