A kind of preparation method of cross-linkable polyimide precipitated fiber

A technology of fibrids and polyimide, applied in the field of fibrids, can solve problems such as the reduction of mechanical properties, and achieve the effects of low cost, controllable molecular weight and rich hairiness

Active Publication Date: 2019-12-10
DONGHUA UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a preparation method of cross-linkable polyimide precipitated fiber, so as to solve the deficiencies in the technology of polyimide precipitated fiber at the present stage. The introduction of cross-linked structure into the fibrids improves the mechanical properties, heat resistance and chemical corrosion resistance of the fibrids, avoiding the shortcomings of the traditional two-step method of reducing the mechanical properties. The fibrids are prepared by the two-step method, and the specific surface area is comparable It is higher than the precipitated fiber of one-step method, and the process is simple and controllable, which improves production efficiency and reduces production cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] (1) Under the protection of nitrogen, add 1.5L NMP, 67.20g PDA and 44.81g BIA to a 5L polymerization kettle, add 112.34g BPDA after completely dissolving, stir at room temperature for 5h, then add 30.86gPEPA and continue stirring for 3h, A polyamic acid stock solution with both ends capped with a solid content of 15% was obtained.

[0033] (2) Filter the polyamic acid stock solution obtained in step (1), defoam, dilute to 5wt%, and then use 10 mL of diluted polyamic acid solution with a porous syringe containing 1 to 10,000 holes and a hole diameter of 0.05 to 1 mm , injected into the stirred 100mL precipitant at an injection speed of 5mL / min, wherein the precipitant is composed of water and NMP with a volume ratio of 2:8, the temperature of the precipitant is 20°C, and the stirring speed is 2000r / min, The stirring time is 1 min, and the polyamic acid precipitated fiber suspension is obtained, which is washed with water and ethanol respectively, filtered, and vacuum-dri...

Embodiment 2

[0037] (1) Under nitrogen protection, add 1L NMP, 67.20g PDA and 44.81g BIA to a 5L polymerization kettle, add 112.34g BPDA after completely dissolving, stir and react at room temperature for 5h, then add 30.86g PEPA and continue stirring for 3h to obtain A polyamic acid stock solution with both ends capped with a solid content of 21%.

[0038] (2) Filter the polyamic acid stock solution obtained in step (1), defoam, dilute to 5wt%, and then use 10 mL of diluted polyamic acid solution with a porous syringe containing 1 to 10,000 holes and a hole diameter of 0.05 to 1 mm , injected into the stirred 100mL precipitant at an injection speed of 5mL / min, wherein the precipitant is composed of water and NMP with a volume ratio of 2:8, the temperature of the precipitant is 20°C, and the stirring speed is 2000r / min, The stirring time is 1 min, and the polyamic acid precipitated fiber suspension is obtained, which is washed with water and ethanol respectively, filtered, and vacuum-dried...

Embodiment 3

[0042] (1) Under the protection of nitrogen, add 1.5L NMP, 67.20g PDA and 44.81g BIA to a 5L polymerization kettle, add 112.34g BPDA after completely dissolving, stir at room temperature for 5h, then add 30.86gPEPA and continue stirring for 3h, A polyamic acid stock solution with both ends capped with a solid content of 15% was obtained.

[0043] (2) Filter the polyamic acid stock solution obtained in step (1), defoam, dilute to 3wt%, and then use 10mL of the diluted polyamic acid solution with a porous syringe containing 1 to 10,000 holes with an inner diameter of 0.05 to 1mm , injected into the stirred 100mL precipitant at an injection speed of 5mL / min, wherein the precipitant is composed of water and NMP with a volume ratio of 2:8, the temperature of the precipitant is 20°C, and the stirring speed is 2000r / min, The stirring time is 1 min, and the polyamic acid precipitated fiber suspension is obtained, which is washed with water and ethanol respectively, filtered, and vacuu...

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Abstract

The invention relates to a cross-linkable polyimide fibrid preparation method which comprises the steps: under nitrogen protection, adding diamine monomer into an aprotic polar solvent, dissolving completely, adding dianhydride monomer to perform stirring reaction under room temperature, then adding an end capping reagent and continuing stirring reaction to obtain two end capped polyamide acid stock solution; filtering, defoaming, diluting and then injecting into stirred precipitation liquid to obtain polyamide acid fibrid suspension liquid and washing, filtering and vacuum drying to obtain polyamide acid fibrid; performing thermal cyclization crosslinking reaction to obtain the polyimide fibrid. The cross-linkable polyimide fibrid preparation method disclosed by the invention has the advantages of simple and controllable technology, energy conservation, environmental friendliness, ability in improving production efficiency and ability in reducing production cost. The prepared cross-linkable polyimide fibrid has the advantages of higher specific surface area and higher mechanical property, thermal resistance and chemical corrosion resistance.

Description

technical field [0001] The invention belongs to the technical field of fibrids, in particular to a preparation method of crosslinkable polyimide fibrids. Background technique [0002] High-performance paper not only has good insulation performance and mechanical strength, but also has various special properties, such as high temperature resistance, radiation resistance, chemical corrosion resistance, etc. have been widely used. Insulating paper made of polyimide has very broad application prospects in high-performance motors, cables, capacitors and transformers, and can also be used to prepare insulating materials such as laminated products, composite materials and prepreg materials. [0003] The most representative of the traditional insulating paper is Nomex paper, a high-temperature-resistant material for H-level insulation, which was successfully researched and produced by DuPont Company of the United States in 1960. With the development of my country's high-tech indust...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): D01F6/74D01F11/08C08G73/10
CPCC08G73/1067D01F6/74D01F11/08
Inventor张清华周建荣赵昕董杰吴婷婷
OwnerDONGHUA UNIV