阅读说明：本技术 一种阻燃再生纤维素纤维及其制备方法 (Flame-retardant regenerated cellulose fiber and preparation method thereof ) 是由 刘晓辉 张秋艳 任元林 郑云波 程博闻 于 2021-10-08 设计创作，主要内容包括：本发明公开了一种阻燃再生纤维素纤维,所述阻燃再生纤维素纤维极限氧指数≥28％、含磷量≤2％。本发明还公开了上述阻燃再生纤维素纤维的制备方法。所述制备方法包括阻燃剂磷酸化生物质的制备、无机阻燃剂分散液的制备、阻燃再生纤维素纤维的制备。本发明所述阻燃再生纤维素纤维,不含传统卤素阻燃剂,使用含磷量极少的纤维素质阻燃剂和无机阻燃剂复配,得到阻燃性能优异的纤维素纤维,大大减少了含磷阻燃剂对环境的危害。阻燃再生纤维素纤维极限氧指数≥28％,磷含量≤2％。(The invention discloses a flame-retardant regenerated cellulose fiber, wherein the limited oxygen index of the flame-retardant regenerated cellulose fiber is more than or equal to 28 percent, and the phosphorus content is less than or equal to 2 percent. The invention also discloses a preparation method of the flame-retardant regenerated cellulose fiber. The preparation method comprises the steps of preparing flame retardant phosphorylated biomass, preparing inorganic flame retardant dispersion liquid and preparing the flame-retardant regenerated cellulose fiber. The flame-retardant regenerated cellulose fiber does not contain the traditional halogen flame retardant, and the cellulose flame retardant with extremely low phosphorus content and the inorganic flame retardant are compounded to obtain the cellulose fiber with excellent flame retardant property, so that the harm of the phosphorus-containing flame retardant to the environment is greatly reduced. The limit oxygen index of the flame-retardant regenerated cellulose fiber is more than or equal to 28 percent, and the phosphorus content is less than or equal to 2 percent.)

1. A flame-retardant regenerated cellulose fiber characterized by: the limit oxygen index of the flame-retardant regenerated cellulose fiber is more than or equal to 28 percent, and the phosphorus content is less than or equal to 2 percent.

2. A preparation method of flame-retardant regenerated cellulose fiber is characterized by comprising the following steps: the preparation method comprises the steps of preparing flame retardant phosphorylated cellulose, preparing inorganic flame retardant dispersion liquid and preparing flame retardant regenerated cellulose fiber.

3. The method for preparing a flame-retardant regenerated cellulose fiber according to claim 2, characterized in that: the preparation of the phosphorylated biomass comprises the steps of adding a phosphorylation reagent and biomass powder into N, N-dimethylformamide according to the mass ratio of 10: 1-1: 10, and reacting at the temperature of 100-160 ℃ for 0.5-28 hours. And then filtering the obtained solution to obtain phosphorylated biomass powder, and fully washing the phosphorylated biomass powder with absolute ethyl alcohol for multiple times to obtain loose phosphorylated biomass powder.

4. The method for preparing flame-retardant regenerated cellulose fiber according to claim 3, wherein the phosphorylation reagent is one or more of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, phytic acid, phosphorous acid, phosphorus pentoxide and the like.

5. The method for preparing flame-retardant regenerated cellulose fiber according to claim 3, wherein the biomass powder is one or more of cellulose powder, chitosan and cyclodextrin.

6. The method for preparing the modified flame-retardant cellulose fiber according to claim 2, wherein the method comprises the following steps: the preparation of the inorganic flame retardant dispersion liquid comprises the steps of adding an aminated carbon nanotube and Mxene into an NMMO aqueous solution with the mass fraction of 50-75%, and carrying out ultrasonic dispersion for 1-6 hours.

7. The method for preparing a flame-retardant regenerated cellulose fiber according to claim 2, characterized in that: preparing the flame-retardant regenerated cellulose fiber, namely adding phosphorylated biomass and cellulose pulp into the inorganic flame-retardant dispersion liquid, uniformly mixing to obtain a flame-retardant spinning solution, and performing spinning molding by a wet spinning process to obtain the flame-retardant regenerated cellulose fiber; the addition amount of the phosphorylated biomass flame retardant is 5-30% of the content of alpha-cellulose in the spinning solution; the addition amount of the inorganic flame retardant is 0.1-3% of the content of alpha-cellulose in the spinning solution.

8. The method of claim 7, wherein the method comprises the steps of: in the wet spinning, the coagulation bath is composed of 1-20% by mass of NMMO aqueous solution, and the temperature of the coagulation bath is 30-50 ℃.

Technical Field

The invention relates to the technical field of functional regenerated cellulose fibers, in particular to a flame-retardant regenerated cellulose fiber and a preparation method thereof.

Background

The fire-proof performance of the textile is related to the life and property safety performance of people, and the improvement of the flame retardant performance of the textile has important significance. In recent years, the attention on the flame-retardant textile at home and abroad is greatly improved, so that higher requirements on the flame-retardant safety performance of the flame-retardant textile are provided. The preparation method of the industrial flame-retardant cellulose fiber textile in the market at present mainly comprises an after-finishing process and a blending and adding process. Among them, Proban and provex CP are commercially available methods for obtaining a flame retardant cellulose fiber product using an after finishing process. The two processes abandon the traditional halogen flame retardant and adopt the phosphorus/nitrogen flame retardant to endow the cellulose textile with excellent flame retardance. However, the release of carcinogens such as formaldehyde has limited widespread use. In order to reduce the problem of toxic substance release, patents CN102482800A and CN103370458A disclose flame retardant viscose fibers and a preparation method thereof, wherein flame retardant regenerated cellulose fibers are prepared by adding flame retardant compounds containing phosphorus, sulfur, nitrogen and the like into viscose spinning solution. The mechanical property of the flame-retardant fiber is reduced by the addition amount of the flame retardant in the production process, and the problem of great loss of the flame retardant exists in the use process. In order to solve the problem that the flame retardant property and the mechanical property of the cellulose fiber are difficult to be considered in the prior art, the patent CN201210555849 prepares the flame retardant regenerated cellulose fiber (viscose) by blending and adding the pyrophosphate flame retardant, and the influence of the flame retardant on the mechanical property of the fiber is compensated to a certain extent. CN110067034A utilizes piperazine pyrophosphate or a compound of piperazine pyrophosphate and other flame retardants as a flame retardant additive to prepare flame-retardant regenerated cellulose fibers (lyocell), and overcomes the problem that the flame retardants are seriously lost in the spinning process of the regenerated cellulose fibers. The combination between the pyrophosphate and piperazine flame retardant and cellulose is poor, so that the flame retardant is not uniformly dispersed in the spinning solution, and the production process is complex and the cost is high. The use of a large amount of the phosphorus-containing flame retardant can also cause certain influence on the ecological environment and generate a biological enrichment phenomenon. Thus, the use of a large amount of phosphorus-containing flame retardants is also not the best choice for flame retarding regenerated cellulose fibers. Patent CN109440213A discloses a graphene oxide modified flame-retardant cellulose fiber and a preparation method thereof, wherein graphene oxide is used as a flame-retardant additive to be added into a regenerated cellulose spinning solution, so that the problems of difficult dispersion of a flame retardant, large addition amount of the flame retardant, easy loss, low fiber strength and the like are solved.

In conclusion, the flame-retardant regenerated cellulose fiber prepared by the prior art has the following defects:

(1) poor compatibility of the flame retardant and the spinning solution and uneven dispersion of the flame retardant in the spinning solution.

(2) The addition of a large amount of phosphorus-containing flame retardant causes the problems of reduction of mechanical properties of the fiber and influence on the environment.

Disclosure of Invention

In view of the above-mentioned shortcomings in the prior art, the present invention aims to provide a flame-retardant regenerated cellulose fiber and a preparation method thereof. The invention prominently solves the technical difficulties that:

(1) the intermiscibility between the flame retardant and the spinning solution is improved, and the flame retardant is uniformly distributed in the spinning solution.

(2) The use of phosphorus-containing flame retardant is reduced.

In order to solve the technical difficulties, the invention adopts the following technical scheme:

the limit oxygen index of the flame-retardant regenerated cellulose fiber is more than or equal to 28 percent, and the phosphorus content is less than or equal to 2 percent.

The preparation method of the flame-retardant regenerated cellulose fiber comprises the steps of preparing flame retardant phosphorylated cellulose, preparing inorganic flame retardant dispersion liquid and preparing the flame-retardant regenerated cellulose fiber.

(1) The preparation of the phosphorylated biomass comprises the steps of adding a phosphorylation reagent and biomass powder into N, N-dimethylformamide according to the mass ratio of 10: 1-1: 10, and reacting at the temperature of 100-160 ℃ for 0.5-28 hours. And then filtering the obtained solution to obtain phosphorylated biomass powder, and fully washing the phosphorylated biomass powder with absolute ethyl alcohol for multiple times to obtain loose phosphorylated biomass powder.

The phosphorylation reagent is one or more of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, phytic acid, phosphorous acid, phosphorus pentoxide and the like.

The biomass powder is one or more of cellulose powder, chitosan and cyclodextrin.

(2) The preparation of the inorganic flame retardant dispersion liquid comprises the steps of adding an aminated carbon nanotube and Mxene into an NMMO aqueous solution with the mass fraction of 50-75%, and carrying out ultrasonic dispersion for 1-6 hours.

(3) Preparing the flame-retardant regenerated cellulose fiber, namely adding phosphorylated biomass and cellulose pulp into the inorganic flame-retardant dispersion liquid, uniformly mixing to obtain a flame-retardant spinning solution, and performing spinning molding by a wet spinning process to obtain the flame-retardant regenerated cellulose fiber; the addition amount of the phosphorylated biomass flame retardant is 5-30% of the content of alpha-cellulose in the spinning solution; the addition amount of the inorganic flame retardant is 0.1-3% of the content of alpha-cellulose in the spinning solution.

In the wet spinning, the coagulation bath is composed of 1-20% by mass of NMMO aqueous solution, and the temperature of the coagulation bath is 0-45 ℃.

The invention has the following beneficial effects:

(1) the flame retardant prepared by the invention is a biomass flame retardant, has good biocompatibility compared with the traditional flame retardant, and can form uniformly dispersed spinning solution with a flame retardant function in a cellulose spinning stock solution.

(2) The inorganic flame retardant aminated carbon nanotube and the Mxene disclosed by the invention can be used as an auxiliary agent to improve the flame retardant property of the fiber and reduce the use of a phosphorus-containing flame retardant, and meanwhile, the addition of the hydrophilic Mxene also increases the dispersibility of the inorganic flame retardant in the fiber spinning solution.

Detailed Description

The present invention will be further described with reference to the following detailed description so that the objects and technical means for realizing the invention will be readily understood. It should be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It should also be understood that various changes or modifications may be made by those skilled in the art to the invention, and such equivalents may fall within the scope of the invention as defined by the appended claims.

Example 1

In this example, the specific steps for preparing the flame-retardant regenerated cellulose fiber are as follows:

(1) preparation of the phosphorylated biomass: 10 g of phosphoric acid and 1.0 g of cellulose powder were added to N, N-dimethylformamide in a mass ratio and reacted at a temperature of 120 ℃ and 160 ℃ for 8 hours. Then, the obtained solution was filtered to obtain phosphorylated cellulose powder, which was then thoroughly washed with anhydrous ethanol several times to obtain loose phosphorylated cellulose powder.

(2) The preparation of the inorganic flame retardant dispersion liquid comprises the steps of adding 0.01 g of aminated carbon nano tube and 0.2 g of Mxene into 10 g of NMMO aqueous solution with the mass fraction of 50%, and carrying out ultrasonic dispersion for 6 hours.

(3) The preparation method of the flame-retardant regenerated cellulose fiber comprises the steps of adding 0.3 g of phosphorylated cellulose and 0.7 g of cellulose pulp into the inorganic flame-retardant dispersion liquid, uniformly mixing to obtain a flame-retardant spinning solution, heating, vacuumizing, mechanically stirring to obtain a spinning solution with a flame-retardant function after the cellulose is completely dissolved, and carrying out processes such as drafting, coagulating bath, drafting and forming to obtain the flame-retardant regenerated cellulose fiber. The detected fiber limit oxygen index is 27.9 percent, and the phosphorus content is 1.24 percent.

Example 2

In this example, the specific steps for preparing the flame-retardant regenerated cellulose fiber are as follows:

(1) preparation of the phosphorylated biomass: 200 g phosphorous acid and 30 g cellulose powder were added to N, N-dimethylformamide and reacted at 130 ℃ for 7 hours. Then, the obtained solution was filtered to obtain phosphorylated cellulose powder, which was then thoroughly washed with anhydrous ethanol several times to obtain loose phosphorylated cellulose powder.

(2) And (3) preparing the inorganic flame retardant dispersion, adding 10 g of aminated carbon nanotube and 0.7 g of Mxene into 500 g of NMMO aqueous solution with the mass fraction of 50%, and performing ultrasonic dispersion for 6 hours.

(3) The preparation method of the flame-retardant regenerated cellulose fiber comprises the steps of adding 15 g of phosphorylated cellulose and 35 g of cellulose pulp into the inorganic flame-retardant dispersion liquid, uniformly mixing to obtain a flame-retardant spinning solution, heating, vacuumizing, mechanically stirring, obtaining a spinning solution with a flame-retardant function after the cellulose is completely dissolved, and carrying out processes such as drafting, coagulating bath, drafting and forming to obtain the flame-retardant regenerated cellulose fiber. The detected fiber limit oxygen index is 27.3 percent, and the phosphorus content is 0.77 percent.

Example 3

In this example, the specific steps for preparing the flame-retardant regenerated cellulose fiber are as follows:

(1) preparation of the phosphorylated biomass: 50 g of pyrophosphoric acid and 5.0 g of cellulose powder were added to N, N-dimethylformamide and reacted at 140 ℃ for 8 hours. Then, the obtained solution was filtered to obtain phosphorylated cellulose powder, which was then thoroughly washed with anhydrous ethanol several times to obtain loose phosphorylated cellulose powder.

(2) The preparation of the inorganic flame retardant dispersion liquid comprises the steps of adding 25 g of aminated carbon nano tube and 5 g of Mxene into 1000 g of NMMO aqueous solution with the mass fraction of 50%, and carrying out ultrasonic dispersion for 6 hours.

(3) The preparation method of the flame-retardant regenerated cellulose fiber comprises the steps of adding 20 g of phosphorylated cellulose and 80 g of cellulose pulp into the inorganic flame-retardant dispersion liquid, uniformly mixing to obtain a flame-retardant spinning solution, heating, vacuumizing, mechanically stirring, obtaining a spinning solution with a flame-retardant function after the cellulose is completely dissolved, and carrying out processes such as drafting, coagulating bath, drafting and forming to obtain the flame-retardant regenerated cellulose fiber. The detected fiber limit oxygen index is 29.9 percent, and the phosphorus content is 0.94 percent.