阅读说明：本技术 一种废旧防弹衣中对位芳纶溶解的方法 (Method for dissolving para-aramid in waste bulletproof clothes ) 是由 侯相林 田梓赏 王玉琪 邓天昇 于 2019-10-29 设计创作，主要内容包括：本发明涉及一种废旧防弹衣中对位芳纶溶解的方法,属于废旧高分子材料循环利用及资源化领域。利用树脂脱除剂对对位芳纶-树脂复合材料中基体树脂的溶胀作用,将对位芳纶纤维和基体树脂分离。然后,利用助溶盐或有机质子酸和溶解剂协同作用,实现了废旧防弹衣中芳纶纤维的溶解。反应条件相对温和,反应过程中所用的溶剂、助溶盐和有机质子酸均可回收再利用。(The invention relates to a method for dissolving para-aramid in waste bulletproof clothes, and belongs to the field of recycling of waste high polymer materials. The swelling effect of the resin remover on the matrix resin in the para-aramid-resin composite material is utilized to separate the para-aramid fiber from the matrix resin. Then, the dissolution of the aramid fiber in the waste bulletproof clothes is realized by utilizing the synergistic effect of the dissolution assisting salt or the organic protonic acid and the dissolving agent. The reaction condition is relatively mild, and the solvent, the solubilizing salt and the organic protonic acid used in the reaction process can be recycled.)

1. A method for dissolving para-aramid in waste bulletproof clothes is characterized by comprising the following steps: the method comprises the following steps: mixing the para-aramid-resin composite material in the waste bulletproof vest with a resin remover, adding the mixture into a reactor, sealing, heating the reactor to remove the resin in the para-aramid-resin composite material, and drying the treated para-aramid for later use; and mixing the para-aramid fiber subjected to resin removal with a dissolving agent, adding a dissolving assisting salt or an organic protonic acid, and heating and stirring until the para-aramid fiber is completely dissolved.

2. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the resin remover is a mixture of a component I and a component II, wherein the component I is one of formic acid, acetic acid or propionic acid, and the component II is one of dichloromethane, trichloromethane or toluene.

3. The method for dissolving para-aramid in waste body armor according to claim 2, wherein the method comprises the following steps: the mass ratio of the first component to the second component in the resin remover is 1: 1-100.

4. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the mass ratio of the para-aramid-resin composite material to the resin remover is 1: 1-100.

5. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the heating temperature for removing the resin in the para-aramid-resin composite material is 0-200 ℃, and the heating time is 1-72 hours.

6. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the dissolving agent is one of concentrated sulfuric acid, N-methyl pyrrolidone, hexamethyl phosphoramide, dimethyl formamide, dimethyl acetamide or dimethyl sulfoxide.

7. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the mass ratio of the para-aramid to the dissolving agent is 1: 1-200.

8. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the solubilizing salt is one of lithium chloride, sodium chloride, potassium chloride or calcium chloride; the organic protonic acid is organic sulfonic acid and comprises one of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid or dodecylbenzenesulfonic acid.

9. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the mass fraction of the dissolution assisting salt or the organic protonic acid in the dissolving agent is 0.5 to 20 percent.

10. The method for dissolving para-aramid in waste body armor according to claim 1, wherein the method comprises the following steps: the heating temperature is 10-180 ℃ when the para-aramid fiber is completely dissolved by heating and stirring, and the heating time is 10 min-72 h.

Technical Field

The invention relates to a method for dissolving para-aramid in waste bulletproof clothes, and belongs to the field of recycling of waste high polymer materials.

Background

DuPont corporation in the 60's of the 20 th century developed a new aramid fiber-para-aramid, which was commercially produced in 1972 and registered as Kevlar for this product. In 1972, the company of Kitikon Japan produced para-Conex fibers; twaron fibers were produced by aksu, the netherlands in 1986; technora fibres were produced in 1987 by the company Imperial Japan. Subsequently, the research and industrialization of the para-aramid fiber are broken through in the countries such as Russia, Korea and the like. Wherein, the DuPont company and the Kitasman company in the United states have absolute technical advantages in the para-aramid industrialization field. In 2018, the total yield of the global para-aramid is about 8.2 ten thousand tons, and the sum of the yields of Dupont and Imperial accounts for about 70% of the total consumption of the global para-aramid. The total amount of para-aramid required in China is estimated to reach 1.2 ten thousand tons in 2020, and 2 ten thousand tons in 2025.

Para-aramid is a high-performance fiber, has excellent properties of ultrahigh strength, high modulus, high temperature resistance, acid and alkali resistance, light weight, impact resistance and the like, is a bulletproof fiber, and is made of para-aramid materials in developed countries such as America and English. Besides military applications, para-aramid has been widely used in various fields of national economy, such as tires and mechanical rubber products, consumer electronics products, concrete structure reinforcement, composite material reinforcement, and the like.

With the wide application of para-aramid fiber, the yield thereof is increasing year by year, and the environmental problems brought therewith gradually raise social concerns. How to realize the recycling of the waste para-aramid fiber is a major challenge for aramid fiber production enterprises and demand enterprises. If the physical dissolution of the para-aramid fiber can be realized, the para-aramid fiber is reused for spinning, the production of para-aramid waste is greatly reduced, and the effective utilization of waste resources is realized. At present, there are reports related to aramid fiber dissolution, for example, dissolving para-aramid fiber by utilizing the synergistic action of protonic acid and organic solvent, "a dissolution method of para-aramid fiber and its application, patent numbers: ZL201410093703.3 "; lithium chloride and dimethyl formamide are utilized to dissolve meta-aramid fiber, namely a method for dissolving aramid fiber, and the application number is 200710017829.2. However, para-aramid in waste body armor is a composite material bonded together by matrix resin, and the recovery of para-aramid in the composite material cannot be realized by simple dissolution, so that the composite material needs to be pretreated to remove the matrix resin on the surface of the fiber. The method can realize the dissolution and recovery of the para-aramid in the waste body armor, and can effectively solve the environmental problems and resource waste caused by para-aramid leftover materials, waste products and the like.

Disclosure of Invention

Aiming at the problems, the invention provides a method for dissolving para-aramid in waste bulletproof clothes.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for dissolving para-aramid in waste body armor comprises the following steps: the method comprises the following steps: mixing the para-aramid-resin composite material in the waste bulletproof vest with a resin remover, adding the mixture into a reactor, sealing, heating the reactor to remove the resin in the para-aramid-resin composite material, and drying the treated para-aramid for later use; and mixing the para-aramid fiber subjected to resin removal with a dissolving agent, adding a dissolving assisting salt or an organic protonic acid, and heating and stirring until the para-aramid fiber is completely dissolved.

Further, the resin remover is a mixture of a component I and a component II, wherein the component I is one of formic acid, acetic acid or propionic acid, and the component II is one of dichloromethane, trichloromethane or toluene. The resin remover selected by the scheme can better remove matrix resin on the surface of the fiber, and is favorable for dissolving and recovering para-aramid in the waste bulletproof clothes.

Furthermore, the mass ratio of the first component to the second component in the resin remover is 1: 1-100. Within the range of the technical scheme, the resin remover can better remove the resin in the para-aramid-resin composite material.

And furthermore, the mass ratio of the para-aramid-resin composite material to the resin remover is 1: 1-100. Within the range of the technical scheme, the para-aramid-resin composite material has better resin removal effect.

And further, the heating temperature for removing the resin in the para-aramid-resin composite material is 0-200 ℃, and the heating time is 1-72 hours. When the heating temperature is lower than 0 ℃, the resin removing agent has no obvious effect on removing the resin in the para-aramid-resin composite material; when the heating temperature is higher than 200 ℃, the resin removing agent does not obviously improve the resin removing effect of the para-aramid-resin composite material; when the heating time is less than 1h, the resin in the para-aramid-resin composite material can not be removed basically; when the heating time is longer than 72h, the resin removing effect in the para-aramid-resin composite material is not obviously improved.

Still further, the dissolving agent is one of concentrated sulfuric acid, N-methyl pyrrolidone, hexamethylphosphoramide, dimethylformamide, dimethylacetamide or dimethyl sulfoxide. Within the range of the technical scheme, the dissolving agent can completely dissolve the para-aramid.

And furthermore, the mass ratio of the para-aramid to the dissolving agent is 1: 1-200. In the range of the technical scheme, the para-aramid is completely dissolved.

Still further, the solubilizing salt is one of lithium chloride, sodium chloride, potassium chloride or calcium chloride; the organic protonic acid is organic sulfonic acid and comprises one of methanesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid or dodecylbenzenesulfonic acid. The solubilizing salt or the protonic acid selected by the scheme has a good synergistic effect with the dissolving solvent, and is beneficial to completely dissolving the para-aramid in the waste bulletproof clothes.

Still further, the mass fraction of the dissolution assisting salt or the organic protonic acid in the dissolving agent is 0.5-20%. In the range of the technical scheme, the para-aramid is completely dissolved.

And further, heating and stirring until the para-aramid fiber is completely dissolved at the heating temperature of 10-180 ℃ for 10 min-72 h. In the range of the technical scheme, the para-aramid is completely dissolved.

Compared with the prior art, the invention has the following advantages:

(1) the swelling effect of the resin remover on the matrix resin in the para-aramid-resin composite material is utilized to separate the matrix resin from the aramid fiber; the dissolution of the para-aramid in the waste bulletproof clothes is realized through the synergistic effect of the dissolution assisting salt or the protonic acid and the dissolution solvent.

(2) The reaction condition is relatively mild, and the solvent, the solubilizing salt and the organic protonic acid used in the reaction process can be recycled.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto.