Selective permeable porous membrane and preparation method thereof

Abstract

The invention belongs to the field of porous membranes, particularly relates to a selective permeable porous membrane and a preparation method thereof, and provides the following scheme aiming at the problem that an existing selective permeable porous membrane is poor in selective permeability. The polytetrafluoroethylene composite material comprises the following raw materials in parts by weight: 50-100 parts of polytetrafluoroethylene resin, 1-10 parts of paraffin oil, 0.5-1 part of a plasticizer, 0.5-1 part of an antioxidant, 0.5-1 part of an ultraviolet light absorber, 0.5-1 part of a pore-foaming agent and 0.5-1 part of a modifier. Comprising the following steps that S1, raw materials are mixed, specifically, polytetrafluoroethylene resin, paraffin oil, a plasticizer, an antioxidant, an ultraviolet light absorber, a pore-foaming agent and a modifying agent are evenly mixed, and through use of the plasticizer, the antioxidant and the ultraviolet light absorber, the performance of the film can be improved; the porosity of the membrane can be increased by adding the pore-foaming agent, so that the pore diameter is increased, and the selective permeability of the membrane is improved.

Description

Technical Field

[0001] The present invention relates to the field of porous membranes, and particularly to a selectively permeable porous membrane and a preparation method thereof. Background Art

[0002] A selectively permeable porous membrane, also known as a selective permeable membrane, is a biological or artificial membrane with special functions. Its core characteristic lies in the selectivity of the passage of substances, that is, allowing certain substances to pass through while blocking other substances from passing through.

[0003] In the prior art, the selective permeability of the selectively permeable porous membrane is poor. Therefore, we propose a selectively permeable porous membrane and a preparation method thereof to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to propose a selectively permeable porous membrane and a preparation method thereof to solve the disadvantage of poor selective permeability of the selectively permeable porous membrane in the prior art.

[0005] A selectively permeable porous membrane proposed by the present invention comprises the following raw materials in parts by weight: 50 - 100 parts of polytetrafluoroethylene resin, 1 - 10 parts of paraffin oil, 0.5 - 1 part of plasticizer, 0.5 - 1 part of antioxidant, 0.5 - 1 part of ultraviolet absorber, 0.5 - 1 part of pore former, 0.5 - 1 part of modifier.

[0006] Preferably, it comprises the following raw materials in parts by weight: 50 parts of polytetrafluoroethylene resin, 1 part of paraffin oil, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of ultraviolet absorber, 0.5 part of pore former, 0.5 part of modifier.

[0007] Preferably, it comprises the following raw materials in parts by weight: 100 parts of polytetrafluoroethylene resin, 10 parts of paraffin oil, 1 part of plasticizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of pore former, 1 part of modifier.

[0008] Preferably, it comprises the following raw materials in parts by weight: 70 parts of polytetrafluoroethylene resin, 5 parts of paraffin oil, 0.7 part of plasticizer, 0.7 part of antioxidant, 0.7 part of ultraviolet absorber, 0.7 part of pore former, 0.7 part of modifier.

[0009] Preferably, the pore former is glycerol or polyethylene glycol.

[0010] The present invention also proposes a preparation method of a selectively permeable porous membrane, comprising the following steps:

[0011] S1. Raw material mixing: Mix the polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore former, and modifier evenly;

[0012] S2. Compression molding: Use a flat vulcanizer to compress the mixed material to form a preliminary film shape;

[0013] S3. Double-roll calendering: Further process through double-roll calendering equipment to make the film reach the required thickness and uniformity;

[0014] S4. Drying treatment: Dry the calendered film to remove moisture and volatiles;

[0015] S5. Multi-directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0016] S6. High-temperature sintering: Place the stretched film in a high-temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0017] Preferably, in S1, polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore-forming agent, and modifier are mixed evenly, the mixing speed is 300 r / min, and the mixing time is 30 - 60 min.

[0018] Preferably, in S6, the stretched film is placed in a high-temperature environment for sintering, the sintering temperature is 350 °C, and finally it is cooled to room temperature to obtain the final selectively permeable porous membrane.

[0019] Preferably, in S3, further process through double-roll calendering equipment to make the film reach the required thickness and uniformity, and the calendering temperature is 60 °C.

[0020] Preferably, in S5, longitudinal stretching is carried out with a stretching ratio of 7 - 9 times; then transverse stretching is carried out with a stretching ratio of 9 - 10 times.

[0021] The beneficial effects of the present invention are as follows:

[0022] By using plasticizer, antioxidant, and ultraviolet absorber, the performance of the membrane can be improved; adding pore-forming agent can increase the porosity of the membrane and enlarge the pore size, thereby improving the selective permeability of the membrane. Specific embodiments

[0023] The following further explains the present invention with specific embodiments.

[0024] Example 1

[0025] The present invention provides a selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 50 parts of polytetrafluoroethylene resin, 1 part of paraffin oil, 0.5 part of plasticizer, 0.5 part of antioxidant, 0.5 part of ultraviolet absorber, 0.5 part of pore-forming agent, and 0.5 part of modifier;

[0026] The preparation method comprises the following steps:

[0027] S1. Raw material mixing: Mix polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore-forming agent, and modifier evenly;

[0028] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0029] S3. Double-roll calendering: Further process through double-roll calendering equipment to make the film reach the required thickness and uniformity;

[0030] S4. Drying treatment: Dry the calendered film to remove the moisture and volatile substances therein;

[0031] S5. Multi-directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0032] S6. High-temperature sintering: Place the stretched film in a high-temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0033] Example 2

[0034] The present invention provides a selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 60 parts of polytetrafluoroethylene resin, 3 parts of paraffin oil, 0.6 part of plasticizer, 0.6 part of antioxidant, 0.6 part of ultraviolet absorber, 0.6 part of pore-forming agent, and 0.6 part of modifier;

[0035] Its preparation method comprises the following steps:

[0036] S1. Raw material mixing: Mix polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore-forming agent, and modifier evenly;

[0037] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0038] S3. Double-roll calendering: Further process through double-roll calendering equipment to make the film reach the required thickness and uniformity;

[0039] S4. Drying treatment: Dry the calendered film to remove the moisture and volatile substances therein;

[0040] S5. Multi-directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0041] S6. High-temperature sintering: Place the stretched film in a high-temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0042] Example Three

[0043] The present invention provides a selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 70 parts of polytetrafluoroethylene resin, 5 parts of paraffin oil, 0.7 part of plasticizer, 0.7 part of antioxidant, 0.7 part of ultraviolet absorber, 0.7 part of pore former, 0.7 part of modifier;

[0044] Its preparation method comprises the following steps:

[0045] S1. Mixing raw materials: Mix polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore former and modifier evenly;

[0046] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0047] S3. Double-roll calendering: Further process through a double-roll calendering device to make the film reach the required thickness and uniformity;

[0048] S4. Drying treatment: Dry the calendered film to remove moisture and volatile substances therein;

[0049] S5. Multi-directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0050] S6. High-temperature sintering: Place the stretched film in a high-temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0051] Example Four

[0052] The present invention provides a selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 90 parts of polytetrafluoroethylene resin, 9 parts of paraffin oil, 0.9 part of plasticizer, 0.9 part of antioxidant, 0.9 part of ultraviolet absorber, 0.9 part of pore former, 0.9 part of modifier;

[0053] Its preparation method comprises the following steps:

[0054] S1. Mixing raw materials: Mix polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore former and modifier evenly;

[0055] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0056] S3. Double-roll calendering: Further process through a double-roll calendering device to make the film reach the required thickness and uniformity;

[0057] S4. Drying treatment: Dry the rolled film to remove moisture and volatiles therein;

[0058] S5. Multi - directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0059] S6. High - temperature sintering: Place the stretched film in a high - temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0060] Example Five

[0061] The present invention provides a selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 100 parts of polytetrafluoroethylene resin, 10 parts of paraffin oil, 1 part of plasticizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of pore - forming agent, 1 part of modifier;

[0062] Its preparation method comprises the following steps:

[0063] S1. Raw material mixing: Mix the polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, pore - forming agent, and modifier evenly;

[0064] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0065] S3. Double - roll calendering: Further process through a double - roll calendering device to make the film reach the required thickness and uniformity;

[0066] S4. Drying treatment: Dry the rolled film to remove moisture and volatiles therein;

[0067] S5. Multi - directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0068] S6. High - temperature sintering: Place the stretched film in a high - temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0069] Comparative Example One

[0070] A selectively permeable porous membrane, which comprises the following raw materials in parts by weight: 50 parts of polytetrafluoroethylene resin, 1 part of paraffin oil;

[0071] Its preparation method comprises the following steps:

[0072] S1. Raw material mixing: Mix the polytetrafluoroethylene resin and paraffin oil evenly;

[0073] S2. Molding by pressing: Use a flat vulcanizer to press the mixed material to form a preliminary film shape;

[0074] S3. Double-roll calendering: Further process through double-roll calendering equipment to make the film reach the required thickness and uniformity;

[0075] S4. Drying treatment: Dry the calendered film to remove moisture and volatiles therein;

[0076] S5. Multi-directional stretching: Stretch the dried film simultaneously or continuously in multiple directions to form a porous structure;

[0077] S6. High-temperature sintering: Place the stretched film in a high-temperature environment for sintering, and finally cool it to room temperature to obtain the final selectively permeable porous membrane.

[0078] Test examples

[0079] Compare the selectively permeable porous membranes prepared in Examples 1 to 5 with the selectively permeable porous membrane prepared in the comparative example, and the results are as follows in the table:

[0080]

[0081] As described above, it is only the preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution of the present invention and its inventive concept, makes equivalent substitutions or changes, and all should be covered within the protection scope of the present invention.

Claims

1. A selective permeable porous membrane, characterized in that: The invention comprises the following raw materials in parts by weight: 50-100 parts of polytetrafluoroethylene resin, 1-10 parts of paraffin oil, 0.5-1 parts of plasticizer, 0.5-1 parts of antioxidant, 0.5-1 parts of ultraviolet absorber, 0.5-1 parts of porogen and 0.5-1 parts of modifier.

2. A selective permeable porous membrane according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 50 parts of polytetrafluoroethylene resin, 1 part of paraffin oil, 0.5 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of ultraviolet absorber, 0.5 parts of porogen and 0.5 parts of modifier.

3. A selective permeable porous membrane according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 100 parts of polytetrafluoroethylene resin, 10 parts of paraffin oil, 1 part of plasticizer, 1 part of antioxidant, 1 part of ultraviolet absorber, 1 part of porogen and 1 part of modifier.

4. A selective permeable porous membrane according to claim 1, characterized in that: The invention comprises the following raw materials in parts by weight: 70 parts of polytetrafluoroethylene resin, 5 parts of paraffin oil, 0.7 parts of plasticizer, 0.7 parts of antioxidant, 0.7 parts of ultraviolet absorber, 0.7 parts of porogen and 0.7 parts of modifier.

5. A selective permeable porous membrane according to claim 1, characterized in that: The porogen is glycerol or polyethylene glycol.

6. A method for preparing a selectively permeable porous membrane, characterized in that: The following steps are involved: S1. Raw material mixing: uniformly mix polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, porogen and modifier; S2. Compression molding: Use a flat vulcanizer to mold the mixed material to form a preliminary film shape; S3, double-roll calendering: further processed by double-roll calendering equipment to make the film reach the required thickness and uniformity; S4, drying treatment: drying the calendered film to remove moisture and volatiles therein; S5. Multi-directional stretching: the dried film is stretched in multiple directions simultaneously or continuously to form a porous structure; S6. High temperature sintering: The stretched film is placed in a high temperature environment for sintering, and finally cooled to room temperature to obtain the final selectively permeable porous membrane.

7. The method for preparing a selectively permeable porous membrane according to claim 6, characterized in that: In the above S1, polytetrafluoroethylene resin, paraffin oil, plasticizer, antioxidant, ultraviolet absorber, porogen and modifier are uniformly mixed at a mixing speed of 300 r / min and a mixing time of 30-60 min.

8. The method for preparing a selectively permeable porous membrane according to claim 6, characterized in that: In the above S6, the stretched film is placed in a high temperature environment for sintering at a temperature of 350°C, and finally cooled to room temperature to obtain a final selectively permeable porous membrane.

9. The method for preparing a selectively permeable porous membrane according to claim 6, characterized in that: In S3, the film is further processed by a double-roll calendering device to achieve the desired thickness and uniformity, and the calendering temperature is 60°C.

10. The method for preparing a selectively permeable porous membrane according to claim 6, characterized in that: In the S5, longitudinal stretching is performed at a stretching ratio of 7-9 times; and then transverse stretching is performed at a stretching ratio of 9-10 times.

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