Preparation method of enhanced polyisophthaloyl metaphenylene diamine hollow fiber membrane

Abstract

The invention discloses a preparation method of an enhanced polyisophthaloyl metaphenylene diamine hollow fiber membrane. The preparation method includes the following processing steps of (1) preparation of a hollow braided hose: adopting a well-known two-dimensional braiding technique to braid fibers into the hollow braided hose, and taking the hollow braided hose as an enhancing body of the enhanced hollow fiber membrane; (2) preparation of PMIA membrane casting dissolving fully dried PMIA resin, additives and a pore-forming agent in an organic solvent at the temperature of 60-70 DEG C, stirring for 4-6h to obtain homogeneous solution, and performing vacuum defoaming to obtain the PMIA membrane casting (3) preparation of the enhanced PMIA hollow fiber membrane: adopting a coextrusion composite spinning process to subject the hollow braided hose obtained in the step (1) and PMIA membrane casting solution obtained in the step (2) to coextrusion through an annular spinning jet, uniformly coating the surface of the hollow braided hose with the membrane casting solution, and fully curing to obtain the enhanced PMIA hollow fiber membrane.

Description

technical field

[0001] The invention belongs to the technical field of membrane preparation, in particular to a method for preparing a reinforced polym-phenylene isophthalamide hollow fiber membrane. Background technique

[0002] Polymphenylene isophthalamide (PMIA) is a typical aromatic polyamide polymer with a large number of amide groups in its molecular chain, so it has strong electronegativity. The high energy barrier between phenylene-amide and C-N bond rotation hinders the molecular chain of polym-phenylene isophthalamide into a fully extended chain conformation, weakening the crystallinity of the molecular chain, so compared with polypara P-phenylene phthalamide (PPTA), its processing and preparation technology is simple. At the same time, the strong hydrogen bond between PMIA molecules stabilizes its chemical structure, which endows PMIA with excellent mechanical properties, high temperature resistance and chemical corrosion resistance, so it has a strong competiti...

Examples

preparation example Construction

[0017] A kind of preparation method of reinforced PMIA hollow fiber membrane, this preparation method adopts following processing steps:

[0018] (1) Preparation of hollow braided tube: adopt known two-dimensional braiding technology to weave fiber into hollow fiber tube, and use this hollow braided tube as the reinforcing body of reinforced hollow fiber membrane; Described fiber is PMIA filament or PMIA and Blended filaments of polyester (PET) filaments; wherein the denier of PMIA and PET filaments is between 200-600D; the blending ratio of PMIA filaments and PET filaments is 1-5:0-5, preferably mixed The braiding ratio is 2:0, 2:1, 3:1, 4:1, 5:1, 1:2, 1:3, 1:4, 1:5; the braided tube diameter is 0.5-2.0mm.

[0019] (2) Preparation of PMIA casting solution: fully dissolve the completely dry PMIA resin, additives and porogen in an organic solvent at 60-70°C, and obtain a homogeneous solution after stirring for 4-6 hours. After vacuum defoaming Make PMIA film-casting liquid; Ea...

Embodiment 1

[0032] (1) Preparation of hollow braided tube: A 24-spindle two-dimensional braiding machine was used to braid PMIA filaments with a specification of 200D into a PMIA hollow braided tube with a diameter of 1.6 mm.

[0033] (2) The preparation of PMIA casting liquid: the additive (CaCl 2 / LiCl=3.5 / 2.5) was mixed and dissolved in the DMAc solution of 74% mass fraction; after it was fully dissolved, the porogen (PVP / PEG=2 / 0, PVP / PEG=2 / 0, PVP (molecular weight 30000) was added to the above system, and stirred at 70 ° C, and after it was completely dissolved, it was defoamed to obtain PMIA casting solution.

[0034] (3) Preparation of reinforced PMIA hollow fiber membrane: Co-extrusion composite spinning technology was used to uniformly coat the above-mentioned PMIA casting solution on the surface of the hollow braided tube through a co-extrusion spinneret at 70°C. At a spinning speed of 0.5 m / min, after passing through an air gap of 25 cm, it enters a coagulation bath at 25° C. f...

Embodiment 2

[0038] (1) Preparation of hollow braided tube: A 24-spindle two-dimensional braiding machine was used to braid PMIA filaments with a specification of 200D into a PMIA hollow braided tube with a diameter of 1.6 mm.

[0039] (2) The preparation of PMIA casting liquid: the additive (CaCl 2 / LiCl=3.5 / 2.5) was mixed and dissolved in the DMAc solution of 74% mass fraction; after it was fully dissolved, the porogen (PVP / PEG=2 / 0, PVP / PEG=2 / 0, PVP (molecular weight 30000) was added to the above system, and stirred at 70 ° C, and after it was completely dissolved, it was defoamed to obtain PMIA casting solution.

[0040] (3) Hollow braided tube pretreatment: the liquid used is 20% H 3 PO 4 Aqueous solution, the temperature used is 50°C, and the treatment time is 5h. After the braided tube is pretreated, the etching of PMIA fibers by phosphoric acid leads to an increase in the roughness of the braided tube fiber, which is beneficial to the improvement of the bonding strength between t...

technical field

[0001] The invention belongs to the technical field of membrane preparation, in particular to a method for preparing a reinforced polym-phenylene isophthalamide hollow fiber membrane. Background technique

[0002] Polymphenylene isophthalamide (PMIA) is a typical aromatic polyamide polymer with a large number of amide groups in its molecular chain, so it has strong electronegativity. The high energy barrier between phenylene-amide and C-N bond rotation hinders the molecular chain of polym-phenylene isophthalamide into a fully extended chain conformation, weakening the crystallinity of the molecular chain, so compared with polypara P-phenylene phthalamide (PPTA), its processing and preparation technology is simple. At the same time, the strong hydrogen bond between PMIA molecules stabilizes its chemical structure, which endows PMIA with excellent mechanical properties, high temperature resistance and chemical corrosion resistance, so it has a strong competiti...

Examples

preparation example Construction

[0017] A kind of preparation method of reinforced PMIA hollow fiber membrane, this preparation method adopts following processing steps:

[0018] (1) Preparation of hollow braided tube: adopt known two-dimensional braiding technology to weave fiber into hollow fiber tube, and use this hollow braided tube as the reinforcing body of reinforced hollow fiber membrane; Described fiber is PMIA filament or PMIA and Blended filaments of polyester (PET) filaments; wherein the denier of PMIA and PET filaments is between 200-600D; the blending ratio of PMIA filaments and PET filaments is 1-5:0-5, preferably mixed The braiding ratio is 2:0, 2:1, 3:1, 4:1, 5:1, 1:2, 1:3, 1:4, 1:5; the braided tube diameter is 0.5-2.0mm.

[0019] (2) Preparation of PMIA casting solution: fully dissolve the completely dry PMIA resin, additives and porogen in an organic solvent at 60-70°C, and obtain a homogeneous solution after stirring for 4-6 hours. After vacuum defoaming Make PMIA film-casting liquid; Ea...

Embodiment 1

[0032] (1) Preparation of hollow braided tube: A 24-spindle two-dimensional braiding machine was used to braid PMIA filaments with a specification of 200D into a PMIA hollow braided tube with a diameter of 1.6 mm.

[0033] (2) The preparation of PMIA casting liquid: the additive (CaCl 2 / LiCl=3.5 / 2.5) was mixed and dissolved in the DMAc solution of 74% mass fraction; after it was fully dissolved, the porogen (PVP / PEG=2 / 0, PVP / PEG=2 / 0, PVP (molecular weight 30000) was added to the above system, and stirred at 70 ° C, and after it was completely dissolved, it was defoamed to obtain PMIA casting solution.

[0034] (3) Preparation of reinforced PMIA hollow fiber membrane: Co-extrusion composite spinning technology was used to uniformly coat the above-mentioned PMIA casting solution on the surface of the hollow braided tube through a co-extrusion spinneret at 70°C. At a spinning speed of 0.5 m / min, after passing through an air gap of 25 cm, it enters a coagulation bath at 25° C. f...

Embodiment 2

[0038] (1) Preparation of hollow braided tube: A 24-spindle two-dimensional braiding machine was used to braid PMIA filaments with a specification of 200D into a PMIA hollow braided tube with a diameter of 1.6 mm.

[0039] (2) The preparation of PMIA casting liquid: the additive (CaCl 2 / LiCl=3.5 / 2.5) was mixed and dissolved in the DMAc solution of 74% mass fraction; after it was fully dissolved, the porogen (PVP / PEG=2 / 0, PVP / PEG=2 / 0, PVP (molecular weight 30000) was added to the above system, and stirred at 70 ° C, and after it was completely dissolved, it was defoamed to obtain PMIA casting solution.

[0040] (3) Hollow braided tube pretreatment: the liquid used is 20% H 3 PO 4 Aqueous solution, the temperature used is 50°C, and the treatment time is 5h. After the braided tube is pretreated, the etching of PMIA fibers by phosphoric acid leads to an increase in the roughness of the braided tube fiber, which is beneficial to the improvement of the bonding strength between t...

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