A fibrous-pored aliphatic polyketone filter membrane and a method for preparing the same

Abstract

The application discloses a kind of aliphatic polyketone filter membranes containing fibrous hole and preparation method thereof, belong to membrane separation technical field.A kind of aliphatic polyketone filter membranes containing fibrous hole, aliphatic polyketone is used as main body resin, F-127 and the like are used as hydrophilic modifier, high melting point adipic acid, phthalic anhydride and the like are used as diluent, dispersed uniformly at 160-200 DEG C, after defoaming, form certain shape, obtain the aliphatic polyketone filter membranes containing fibrous hole.The special fibrous hole structure of the aliphatic polyketone filter membranes is different from the classic finger hole and sponge hole structure, has the performance advantage of combining the advantages of both, and POK is low in price, good in hydrophilicity, good in solvent resistance, has good application prospect in membrane filtration field.

Description

Technical Field

[0001] This invention belongs to the technical field of separation membranes, specifically relating to an aliphatic polyketide filtration membrane containing fibrous pores and its preparation method. Background Technology

[0002] Chinese patent CN201280043773.7 provides a polyketone porous membrane, which has good heat resistance and reagent resistance, making it suitable as a filter with high particle capture efficiency and as a separator for batteries or capacitors with low permeation resistance for ions. Chinese patent CN202110549991.9 also provides a polylactic acid porous material containing fibrous pores and its preparation method, solving the technical problems of difficulty in controlling the pore structure of porous materials in the prior art, as well as the use of organic solvents and insufficient mechanical strength. Filter membranes typically exhibit two typical structures: sponge-like pore structure and finger-like pore structure. Generally speaking, membranes with finger-like pore structures have low strength, low retention, and are easy to clean, while membranes with sponge-like pore structures have higher strength and retention but are difficult to clean.

[0003] Polyvinylidene fluoride (PVDF) is widely used in water treatment, solar power generation, architectural membrane structures, and pharmaceutical packaging. However, due to its high material cost, commercial production and usage costs are high, and its high hydrophobicity necessitates hydrophilic modification during the filtration of water treatment solutions, making the process complex. POK, a linearly structured crystalline thermoplastic engineering material polymerized from carbon monoxide and olefins, possesses advantages such as high mechanical properties, high melting point, solvent resistance, and excellent abrasion resistance due to its high crystallinity. As an engineering plastic, POK's performance fully meets the requirements for membrane fabrication, and its price is much lower than PVDF. With its good hydrophilicity, POK is expected to replace expensive PVDF as the preferred membrane material. Summary of the Invention

[0004] The purpose of this invention is to provide an aliphatic polyketide (POK) filtration membrane containing fibrous pores and its preparation method. This filtration membrane has a special fibrous pore structure, which combines the structural advantages of finger-like pore membranes and sponge-like pore membranes. Furthermore, POK is cheaper than commonly used membrane material PVDF, and has promising application prospects. This invention can be achieved through the following technical solutions:

[0005] An aliphatic polyketone filter membrane containing fibrous pores, wherein the filter membrane uses aliphatic polyketone as the membrane material and the interior of the filter membrane exhibits fibrous pores, specifically including the following steps:

[0006] Aliphatic polyketone, hydrophilic modifier and diluent are added to a container, heated and mixed, and then vacuum degassed to obtain casting solution;

[0007] The casting solution is used to produce a primary film on a molding device;

[0008] The nascent membrane is placed in a pure water cooling bath, where it undergoes cooling and phase separation, crystallization with a diluent, and solidification into a membrane.

[0009] The cured membrane is immersed in pure water, then in an aqueous glycerol solution, and then air-dried or oven-dried to obtain an aliphatic polyketide filter membrane with fibrous pores.

[0010] Furthermore, the weight ratio of the aliphatic polyketone resin, hydrophilic modifier, and diluent is 15-25:1-10:65-80.

[0011] Furthermore, the hydrophilic modifier includes one or a mixture of F-127 and F-108.

[0012] Furthermore, the melting point of the diluent is greater than 90°C.

[0013] Furthermore, the diluent includes one or more of adipic acid, phthalic anhydride, glutaric acid, pimelic acid, azelaic acid, octanoic acid, and p-hydroxybenzaldehyde.

[0014] The present invention has the following advantages and beneficial effects:

[0015] 1. The diluent used is water-soluble, and water can be used as an extractant, making the production process safe and environmentally friendly.

[0016] 2. A filter membrane with a fibrous pore structure was obtained, which combines the advantages of finger-like pores and sponge-like pores. Attached Figure Description

[0017] Figure 1 This is a scanning electron microscope image of a cross-section of the aliphatic polyketide filter membrane of Example 1 of the present invention.

[0018] Figure 2 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 2 of the present invention.

[0019] Figure 3 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 3 of the present invention.

[0020] Figure 4 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 4 of the present invention.

[0021] Figure 5 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 5 of the present invention.

[0022] Figure 6 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 6 of the present invention.

[0023] Figure 7This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Example 7 of the present invention.

[0024] Figure 8 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Comparative Example 1 of the present invention.

[0025] Figure 9 This is a scanning electron microscope image of the cross-section of the aliphatic polyketide filter membrane of Comparative Example 2 of the present invention. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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.

[0027] Example 1:

[0028] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0029] S1. Add 20 parts of POK, 3 parts of hydrophilic modifier F-127, and 77 parts of phthalic anhydride to a container and mix. Heat to 160°C and after thorough and uniform dispersion, vacuum degas the mixture.

[0030] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0031] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 45℃ and the curing time at 0.5h.

[0032] S4. Immerse the cured membrane in pure water at 60℃ for 24 hours, then immerse it in a 20% glycerol aqueous solution for 24 hours. After air drying, an aliphatic polyketide flat sheet filter membrane with fibrous pores is obtained.

[0033] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 700L / (m²). 2 ·h).

[0034] Example 2:

[0035] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0036] S1. Add 20 parts POK, 5 parts hydrophilic modifier F-127, and 75 parts pimelic acid to a container and mix. Heat to 170°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0037] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0038] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 60℃, and the curing time at 0.5h.

[0039] S4. Immerse the cured membrane in pure water at 80℃ for 24 hours, then immerse it in a 20% glycerol aqueous solution for 24 hours. After air drying, an aliphatic polyketide flat sheet filter membrane with fibrous pores is obtained.

[0040] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 600L / (m²). 2 ·h).

[0041] Example 3:

[0042] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0043] S1. Add 25 parts POK, 6 parts hydrophilic modifier F-108, and 69 parts adipic acid to a container and mix. Heat to 180°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0044] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0045] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 50℃ and the curing time at 0.5h.

[0046] S4. The cured membrane is immersed in pure water at 80℃ for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 45℃ to obtain an aliphatic polyketide flat sheet filter membrane with fibrous pores.

[0047] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 300L / (m²). 2 ·h).

[0048] Example 4:

[0049] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0050] S1. Add 25 parts of POK, 3 parts of hydrophilic modifier F-108, and 72 parts of p-hydroxybenzaldehyde to a container and mix. Heat to 170°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0051] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0052] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 45℃ and the curing time at 0.5h.

[0053] S4. The cured membrane is immersed in pure water at 60℃ for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 45℃ to obtain an aliphatic polyketide flat sheet filter membrane with fibrous pores.

[0054] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 650L / (m²). 2 ·h).

[0055] Example 5:

[0056] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0057] S1. Add 25 parts POK, 2 parts hydrophilic modifier F-108, and 73 parts glutaric acid to a container and mix. Heat to 160°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0058] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0059] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 45℃ and the curing time at 0.5h.

[0060] S4. The cured membrane is immersed in pure water at 70°C for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 35°C to obtain an aliphatic polyketide flat sheet filter membrane with fibrous pores.

[0061] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 700L / (m²). 2 ·h).

[0062] Example 6:

[0063] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0064] S1. Add 25 parts POK, 3 parts hydrophilic modifier F-127, and 72 parts adipic acid to a container and mix. Heat to 180°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0065] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0066] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 40℃, and the curing time at 0.5h.

[0067] S4. The cured membrane is immersed in pure water at 60℃ for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 40℃ to obtain an aliphatic polyketide flat sheet filter membrane with fibrous pores.

[0068] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 300L / (m²). 2 ·h).

[0069] Example 7:

[0070] An aliphatic polyketide filter membrane containing fibrous pores and its preparation method, the preparation method comprising the following steps:

[0071] S1. Add 20 parts POK, 4 parts hydrophilic modifier F-127, and 76 parts octanoic acid to a container and mix. Heat to 170°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0072] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0073] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 45℃ and the curing time at 0.5h.

[0074] S4. The cured membrane is immersed in pure water at 80℃ for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 35℃ to obtain an aliphatic polyketide flat sheet filter membrane with fibrous pores.

[0075] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 500L / (m²). 2 ·h).

[0076] Comparative Example 1:

[0077] S1. Add 20 parts of POK, 3 parts of hydrophilic modifier F-127, and 77 parts of dimethyl sulfoxide to a container and mix. Heat to 140°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0078] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0079] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 45℃ and the curing time at 0.5h.

[0080] S4. The cured membrane is immersed in pure water at 60°C for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 35°C to obtain an aliphatic polyketide flat sheet filter membrane with sponge-like pores.

[0081] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 350L / (m²). 2 ·h).

[0082] Comparative Example 2:

[0083] S1. Add 20 parts of POK, 1 part of hydrophilic modifier F-108, and 79 parts of diethylene glycol to a container and mix. Heat to 160°C and after fully dispersing and homogenizing, vacuum degas the mixture.

[0084] S2. Prepare flat sheet films by applying the casting solution to an automatic film coating machine;

[0085] S3. Immediately immerse the newly formed flat sheet membrane in a pure water cooling bath, with the water temperature controlled at 50℃ and the curing time at 0.5h.

[0086] S4. The cured membrane is immersed in pure water at 70°C for 24 hours, then immersed in 20% glycerol aqueous solution for 24 hours, and dried at 35°C to obtain an aliphatic polyketide flat sheet filter membrane with sponge-like pores.

[0087] The pure water flux of the flat sheet membrane at 25℃ and 0.1MPa is 400L / (m²). 2 ·h).

[0088] The experimental results of Examples 1-7, Comparative Examples 1 and 2 were statistically analyzed, and the results are shown in Table 1 below:

[0089] Table 1

[0090]

[0091]

[0092] The analysis of the above results shows that:

[0093] (1) As can be seen from Examples 1 to 7, the films prepared using diluents with melting points higher than 90°C all exhibited fibrous porous structures;

[0094] (2) The films prepared by diluents with melting points below 90°C in the comparative examples all exhibited a sponge-like structure and failed to show the desired fibrous pore structure.

[0095] (3) The raw material ratios of Example 1 (the melting point of the diluent is higher than 90°C) and Comparative Example 1 (the melting point of the diluent is lower than 90°C) are the same. By comparison, it was found that the pure water flux of the membrane in Example 1 is significantly higher than that in Comparative Example 1, which shows that the fibrous porous membrane structure is superior to the sponge porous membrane structure.

[0096] (4) As can be seen from the process of Examples 1 to 7, the diluent used to prepare the membrane has excellent water solubility. During the preparation process, no additional extractant is needed for extraction. It is directly extracted and separated by water during the water bath process.

[0097] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A filter membrane, characterized in that, The filter membrane comprises the following raw materials: aliphatic polyketone, hydrophilic modifier, and diluent; The weight ratio of the aliphatic polyketone, hydrophilic modifier, and diluent is 15-25:1-10:65-80; The melting point of the diluent is greater than 90°C; The diluent includes one or more of the following: adipic acid, phthalic anhydride, glutaric acid, pimelic acid, azelaic acid, octanoic acid, and p-hydroxybenzaldehyde; The filter membrane has a fibrous porous structure inside.

2. The filter membrane according to claim 1, characterized in that, The hydrophilic modifier includes one or more mixtures of F-108 and F-127.

3. The application of the filter membrane according to any one of claims 1 to 2 in the field of organic separation membranes.

4. A method for preparing a filter membrane as described in any one of claims 1-2, characterized in that, The method includes the following steps: Aliphatic polyketone, hydrophilic modifier and diluent are added to a container, heated and mixed, and then vacuum degassed to obtain casting solution; The casting solution is used to produce a primary film on a molding device; The nascent membrane is placed in a pure water cooling bath, where it undergoes cooling and phase separation, crystallization with a diluent, and solidification into a membrane. The cured membrane is immersed in pure water, then in an aqueous glycerol solution, and then air-dried or oven-dried to obtain an aliphatic polyketide filter membrane with fibrous pores.

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