Radiation-resistant organic silicon modified polyurethane as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high polymer materials, and particularly relates to radiation-resistant organic silicon modified polyurethane as well as a preparation method and application thereof. The irradiation-resistant organic silicon modified polyurethane is prepared from hydroxyalkyl-terminated silicone oil, isocyanate containing a conjugated structure and dihydric alcohol containing a conjugated structure. Organic silicon is adopted as a soft segment of the material, high bond energy and high thermal stability of a Si-O bond are utilized to improve the irradiation resistance of the material, and isocyanate and dihydric alcohol containing a conjugated structure are adopted as a hard segment and a chain extender respectively, so that the strength is improved, the irradiation shielding capability of the conjugated structure is utilized, and the irradiation resistance and mechanical properties are improved; the radiation-resistant elastomer can meet the use requirements of high-radiation places, and can be used in the fields of radiation-resistant coatings, radiation-resistant elastomers and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials, and specifically relates to a radiation-resistant silicone-modified polyurethane and a preparation method and application thereof. Background Art

[0002] With the increasing depletion of fossil energy, nuclear power as a high-efficiency energy source has gradually become an important part of the global energy structure. The coatings for nuclear power plant equipment and facilities that match it have also become a hot topic of research. Among them, coatings with polymer materials as film-forming materials play a vital role in the nuclear power industry. Currently, the commonly used polymer film-forming materials mainly include epoxy resins, silicones, alkyd resins, phenolic resins, polyesters and polyurethanes, but single-component polymer materials have certain defects. After being irradiated by microscopic particle flows, its disadvantages are easily exposed, showing phenomena such as powdering, shedding, and cracking. Therefore, in order to further improve the radiation resistance of polymer materials themselves, it is urgent to develop a method for modifying single-component resins. Summary of the invention

[0003] The present invention aims to solve at least one of the problems existing in the above-mentioned prior art. To this end, the present invention provides a radiation-resistant silicone-modified polyurethane and a preparation method and application thereof. Silicone (mainly polysiloxane) has good thermal stability and high bond energy, while polyurethane has relatively strong adhesion. Modifying polyurethane with silicone can overcome the problem of insufficient adhesion of silicone itself, and to a certain extent can make up for the shortcomings of both, so that the adhesion and weather resistance of the material are improved, and the conjugated structure of the material can further improve the radiation resistance of the material.

[0004] In order to achieve the above objectives, the specific technical solutions are as follows: A radiation-resistant organosilicon-modified polyurethane is prepared from the following raw materials: hydroxyalkyl-terminated silicone oil, isocyanate containing a conjugated structure, diol containing a conjugated structure, and a catalyst.

[0005] Preferably, the hydroxyalkyl-terminated silicone oil is hydroxyalkyl-terminated polydimethyl silicone oil, hydroxyalkyl-terminated polymethylphenyl silicone oil, or hydroxyalkyl-terminated ethylphenyl silicone oil.

[0006] Preferably, the isocyanate containing a conjugated structure is toluene diisocyanate, diphenylmethane diisocyanate or naphthalene diisocyanate.

[0007] Preferably, the diol containing a conjugated structure is hydroquinone di(2-hydroxyethyl) ether or 4-hydroxyethyloxyethyl-1-hydroxyethylphenylene diether.

[0008] Preferably, the catalyst is an organotin catalyst.

[0009] A method for preparing the radiation-resistant silicone-modified polyurethane comprises the following steps: (1) Using hydroxyalkyl-terminated silicone oil and isocyanate containing a conjugated structure as raw materials, reacting under the action of a catalyst to obtain an isocyanate-terminated prepolymer; (2) After the reaction in step (1) is completed, a diol containing a conjugated structure is added to react with the isocyanate-terminated prepolymer to obtain the radiation-resistant silicone-modified polyurethane.

[0010] Furthermore, the preparation method also includes precipitation and separation steps, and the precipitant is methanol or water.

[0011] Furthermore, the mass ratio of the hydroxyalkyl-terminated silicone oil, the isocyanate containing a conjugated structure, the diol containing a conjugated structure and the catalyst is (20-60):(5-30):(5-15):(0.002-0.005).

[0012] Furthermore, in step (1), the reaction temperature is 30-80°C, and the reaction time is 2-4h; in step (2), the reaction temperature is 30-70°C, and the reaction time is 4-8h.

[0013] An application of the radiation-resistant silicone-modified polyurethane in the field of radiation resistance, including radiation-resistant coatings and radiation-resistant elastomers.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention adopts silicone as the soft segment of the material, and utilizes the high bond energy and high thermal stability of the Si-O bond to improve its radiation resistance; and the present invention adopts isocyanate and diol containing a conjugated structure as the hard segment and chain extender respectively, which not only improves the strength but also utilizes the radiation shielding ability of the conjugated structure, thereby improving its radiation resistance and mechanical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The schematic diagram of the synthesis route of the radiation-resistant silicone-modified polyurethane of the present invention is as follows: Figure 2 is the stress-strain curve of the silicone-modified polyurethane film sample; Figure 3 a is a graph showing the variation trend of the storage modulus of the organosilicon-modified polyurethane of Example 1 at different irradiation doses with temperature; Figure 3 b is a graph showing the variation trend of the loss factor of the silicone-modified polyurethane in Example 1 with temperature under different radiation doses. DETAILED DESCRIPTION

[0016] The principles and features of the present invention are described below with reference to examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention. The experimental methods used in the following examples are conventional methods unless otherwise specified; the materials, reagents, etc. used in the following examples are all commercially available unless otherwise specified. Figure 1 The schematic diagram of the synthesis route of the radiation-resistant silicone-modified polyurethane of the present invention is shown in FIG. Example 1

[0017] A radiation-resistant silicone-modified polyurethane, the preparation method of which comprises the following steps: (1) First, in a nitrogen atmosphere, toluene diisocyanate (TDI) and N,N-dimethylformamide (DMF) were mixed in a three-necked flask in a mass ratio of 1:2, and then a catalyst DBTDL was added and stirred at 70°C to ensure that all the ingredients were evenly mixed; the mass proportions of toluene diisocyanate and catalyst were 5 parts and 0.002 parts, respectively.

[0018] (2) Mix hydroxypropyl-terminated polydimethylsilicone and N,N-dimethylformamide (DMF) in a ratio of 1:2 (wherein the mass proportion of hydroxypropyl-terminated polydimethylsilicone is 20 parts), place in a constant pressure dropping funnel and slowly drip into a three-necked flask, and react at 70°C for 3 hours.

[0019] (3) Mix hydroquinone di(2-hydroxyethyl) ether and N,N-dimethylformamide (DMF) in a ratio of 1:3 (wherein the mass fraction of hydroquinone di(2-hydroxyethyl) ether is 5 parts), then add the mixture dropwise into a three-necked flask and react at 70°C for 4 hours.

[0020] (4) After the reaction is completed, methanol is used for precipitation and the product is separated from the solvent by a suction filtration device, and then vacuum dried at 60°C to remove residual solvent and moisture.

[0021] The modified polyurethane obtained in this embodiment has good film-forming properties. Figure 2 It can be obtained that its tensile strength is 10.8MPa, and after electron beam irradiation, the material is cross-linked, and the strength increase proves that it has good radiation resistance ( Figure 3 a-3b), can meet the use requirements of high-irradiation places and be used as radiation-resistant coatings, radiation-resistant elastomers, etc. Example 2

[0022] A radiation-resistant silicone-modified polyurethane, the preparation method of which comprises the following steps: (1) First, in a nitrogen atmosphere, toluene diisocyanate (TDI) and N,N-dimethylformamide (DMF) were mixed in a three-necked flask in a mass ratio of 1:2, and then a catalyst DBTDL was added and stirred at 70°C to ensure that all the ingredients were evenly mixed; the mass proportions of toluene diisocyanate and catalyst were 15 parts and 0.003 parts, respectively.

[0023] (2) Mix hydroxypropyl-terminated polydimethylsilicone and N,N-dimethylformamide (DMF) in a ratio of 1:2 (wherein the mass proportion of hydroxypropyl-terminated polydimethylsilicone is 40 parts), place in a constant pressure dropping funnel and slowly drip into a three-necked flask, and react at 70°C for 4 hours.

[0024] (3) Mix hydroquinone di(2-hydroxyethyl) ether and N,N-dimethylformamide (DMF) in a ratio of 1:3 (wherein the mass fraction of hydroquinone di(2-hydroxyethyl) ether is 10 parts), then dropwise add the mixture into a three-necked flask and react at 50°C for 8 hours.

[0025] (4) After the reaction is completed, methanol is used for precipitation and the product is separated from the solvent by a suction filtration device, and then vacuum dried at 60°C to remove residual solvent and moisture. Example 3

[0026] A radiation-resistant silicone-modified polyurethane, the preparation method of which comprises the following steps: (1) First, in a nitrogen atmosphere, toluene diisocyanate (TDI) and N,N-dimethylformamide (DMF) were mixed in a three-necked flask in a mass ratio of 1:2, and then a catalyst DBTDL was added and stirred at 70°C to ensure that all the ingredients were evenly mixed; the mass proportions of toluene diisocyanate and catalyst were 30 parts and 0.005 parts, respectively.

[0027] (2) Mix hydroxypropyl-terminated polydimethylsilicone and N,N-dimethylformamide (DMF) in a ratio of 1:2 (wherein the mass proportion of hydroxypropyl-terminated polydimethylsilicone is 60 parts), place in a constant pressure dropping funnel and slowly drip into a three-necked flask, and react at 80°C for 4 hours.

[0028] (3) Mix hydroquinone di(2-hydroxyethyl) ether and N,N-dimethylformamide (DMF) in a ratio of 1:3 (wherein the mass fraction of hydroquinone di(2-hydroxyethyl) ether is 15 parts), then add dropwise into a three-necked flask and react at 70°C for 4 hours.

[0029] (4) After the reaction is completed, methanol is used for precipitation and the product is separated from the solvent by a suction filtration device, and then vacuum dried at 60°C to remove residual solvent and moisture.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A radiation-resistant silicone-modified polyurethane, characterized in that: The radiation-resistant organic silicon modified polyurethane is prepared by using the following raw materials: hydroxyalkyl-terminated silicone oil, isocyanate containing a conjugated structure, diol containing a conjugated structure and a catalyst.

2. The radiation-resistant silicone-modified polyurethane according to claim 1, characterized in that: The hydroxyalkyl-terminated silicone oil is hydroxyalkyl-terminated polydimethyl silicone oil, hydroxyalkyl-terminated polymethylphenyl silicone oil, and hydroxyalkyl-terminated ethylphenyl silicone oil.

3. The radiation-resistant silicone-modified polyurethane according to claim 1, characterized in that: The isocyanate containing a conjugated structure is toluene diisocyanate, diphenylmethane diisocyanate or naphthalene diisocyanate; The diol containing a conjugated structure is hydroquinone di(2-hydroxyethyl) ether or 4-hydroxyethyloxyethyl-1-hydroxyethylbenzene diether; The catalyst is an organotin catalyst.

4. A method for preparing the radiation-resistant silicone-modified polyurethane according to any of claims 1 to 3, characterized in that: The preparation method comprises the following steps: (1) Using hydroxyalkyl-terminated silicone oil and isocyanate containing a conjugated structure as raw materials, reacting under the action of a catalyst to obtain an isocyanate-terminated prepolymer; (2) After the reaction in step (1) is completed, a diol containing a conjugated structure is added to react with the isocyanate-terminated prepolymer to obtain the radiation-resistant silicone-modified polyurethane.

5. The preparation method according to claim 4, characterized in that: The mass proportions of the hydroxyalkyl-terminated silicone oil, the isocyanate containing a conjugated structure, the diol containing a conjugated structure and the catalyst are (20-60): (5-30): (5-15): (0.002-0.005).

6. The preparation method according to claim 4, characterized in that: In the step (1), the reaction temperature is 30-80° C. and the reaction time is 2-4 h.

7. The preparation method according to claim 4, characterized in that: In the step (2), the reaction temperature is 30-70° C. and the reaction time is 4-8 h.

8. Use of the radiation-resistant organosilicon-modified polyurethane as claimed in any one of claims 1 to 3 in the field of radiation resistance.

9. The use according to claim 8, characterized in that: The applications include radiation resistant coatings, radiation resistant elastomers.

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