Method for recycling waste aramid-mica composite paper

Patent metadata

Field	Value
Publication number	US-2022340730-A1
Application number	US-202217858952-A
Country	US
Kind code	A1
Filing date	Jul 6, 2022
Priority date	Apr 12, 2022
Publication date	Oct 27, 2022
Grant date	—

Abstract

The disclosure relates to resource recycling, and more particularly to a green and efficient method for recycling waste aramid-mica composite paper. The method includes: dissolution of aramid-mica composite paper scraps, separation of mica flakes; phase separation, filtration, recycling of organic solvent and collection of aramid fiber.

First claim

What is claimed is:

1 . A method for recycling waste aramid-mica composite paper, comprising:
(S1) pre-processing the waste aramid-mica composite paper to obtain a dehydrated aramid-mica composite paper scrap; (S2) dissolving the dehydrated aramid-mica composite paper in a mixture solution to obtain a mixture system A, wherein the mixture solution comprises a dispersing agent, an alkali, and an organic solvent; (S3) filtering the mixture system A with a primary filter to obtain a mica flake and an aramid fiber solution; (S4) adding a replacement solvent to the aramid fiber solution for solvent replacement and phase separation to obtain an aramid fiber suspension; (S5) filtering the aramid fiber suspension with a secondary filter to obtain an aramid fiber gel and a mixture system B composed of the organic solvent and the dispersing agent; and (S6) subjecting the mixture system B to distillation at a preset temperature to recycle the organic solvent; and drying the aramid fiber gel to collect aramid fiber.

2 . The method of claim 1 , wherein in step (S1), the waste aramid-mica composite paper is aramid-mica paper or a paper-based material with poly(m-phenylene isophthalamide) as polymer matrix.

3 . The method of claim 1 , wherein a size of the dehydrated aramid-mica composite paper scrap is 2-5 cm 2 .

4 . The method of claim 1 , wherein in step (S2), the mixture solution is prepared through steps of:
dissolving the alkali in the dispersing agent to form a mixture followed by addition of the organic solvent and stirring to obtain the mixture solution; wherein a ratio of the dispersing agent to the alkali to the organic solvent is 1 mL: (1-2) g: (300-600) mL.

5 . The method of claim 4 , wherein the dispersing agent is water, ethanol, methanol, or a combination thereof; the alkali is solid potassium hydroxide, solid sodium hydroxide, or a combination thereof; and the organic solvent is dimethyl sulfoxide, dimethyl formamide, or a combination thereof.

6 . The method of claim 1 , wherein the primary filter is a 100-200 mesh filter; and the secondary filter mesh is a 400-1000 mesh filter.

7 . The method of claim 1 , wherein in step (S4), a volume ratio of the replacement solvent to the aramid fiber solution is (2-3):1.

8 . The method of claim 1 , wherein the replacement solvent is water or ethanol.

9 . The method of claim 8 , wherein in step (S6), when the replacement solvent is water, the preset temperature is 100-105° C.; and when the replacement solvent is ethanol, the preset temperature is 75-78° C.

10 . The method of claim 1 , wherein in step (S6), the drying of the aramid fiber gel is performed at 60-100° C. for 4-24 h.

Assignees

• Shaanxi Univ Of Science & Technology

Inventors

• Lu Zhaoqing
• Jia Fengfeng
• Hua Li
• E Songfeng
• Liu Yuanqing
• Dong Jiayue
• Li Nan
• Geng Bo

Classifications

• B09B2101/85

  Paper; Wood; Fabrics, e.g. cloths · CPC title

• B09B3/80

  involving an extraction step · CPC title

• B09B2101/75

  Plastic waste · CPC title

• C01B33/20 Primary

  Silicates (persilicates C01B15/14 {; containing aluminium C01B33/26}) · CPC title

• C08J2377/10

  Polyamides derived from aromatically bound amino and carboxyl groups of amino carboxylic acids or of polyamines and polycarboxylic acids · CPC title