A biomass blended flame-retardant cellulose fiber material, its preparation method and application

Abstract

The present invention discloses a biomass blended flame-retardant cellulose fiber material, its preparation method and application, belonging to the technical field of cellulose fiber material preparation. The method comprises the following steps: (1) dissolving a polyhydroxy biomass carbon source and phosphazene, then adding an alkaline reagent to carry out a substitution reaction, and obtaining a polyhydroxy biomass intumescent flame retardant after the reaction is completed; (2) preparing a cellulose spinning solution, adding the polyhydroxy biomass intumescent flame retardant, and carrying out a defoaming treatment to obtain a flame-retardant cellulose spinning solution; (3) adopting a wet spinning process to spin the flame-retardant cellulose spinning solution to obtain the biomass blended flame-retardant cellulose fiber material. Through the chemical modification of the polyhydroxy biomass carbon source, an intumescent flame retardant containing flame-retardant components such as phosphorus and nitrogen is constructed, which can give full play to the synergistic flame-retardant effect of the acid source, carbon source and gas source, has high flame-retardant efficiency, low addition amount, and can well retain the excellent properties of the original cellulose fiber.

Description

Technical Field

[0001] The present invention relates to the technical field of the preparation of cellulose fiber materials, and particularly to a biomass blended flame-retardant cellulose fiber material, a preparation method thereof, and an application thereof. Background Art

[0002] Cellulose, a macromolecular polysaccharide derived from natural plants, has received extensive attention due to its abundance, renewability, and biodegradability. Cellulose fibers prepared by NMMO wet spinning, namely Lyocell fibers, even enjoy the reputation of "green fibers in the 21st century". However, the flammability caused by the high carbon and hydrogen element content of cellulose fibers seriously threatens people's lives and property safety. Therefore, developing flame-retardant cellulose fibers has great practical significance.

[0003] So far, halogen-based flame retardants have been widely used due to their low price and high flame-retardant performance. For example, polybrominated diphenyl ethers were once widely used for the flame-retardant modification of textiles, but they will release pollutants that are permanently harmful to the human body and the natural environment. N-hydroxymethyl-3-(dimethoxyphosphoryl) propionamide (Pyrovatex CP) and ammonia-cured and polycondensed tetrakis (hydroxymethyl) phosphonium chloride-urea derivatives (Proban) have become the most commonly used flame retardants in the industrial production of flame-retardant cellulose products. However, due to the presence of nitrogen hydroxymethyl on the side groups of these two flame retardants, they will inevitably degrade and release formaldehyde during processing and use, and formaldehyde is considered a serious carcinogen. Therefore, there is an urgent need to develop sustainable and environmentally friendly flame retardants.

[0004] In recent years, developing high-performance materials using biomass resources to replace petroleum-derived chemicals is a key direction of the sustainable development strategy. It is worth noting that the polyhydroxy structures of natural saccharide compounds and polyphenol compounds, such as cyclodextrin, starch, etc., are highly similar to cellulose molecules. Therefore, based on the principle of "similar compatibility of molecular structures", designing biomass intumescent flame retardants adapted to the cellulose molecular structure with polyhydroxy biomass molecules has good structural advantages. However, there is currently no report on the related technology of preparing flame-retardant materials using polyhydroxy biomass molecules as raw materials. Summary of the Invention

[0005] The purpose of the present invention is to provide a biomass blended flame-retardant cellulose fiber material, a preparation method thereof, and an application thereof to solve the problems existing in the above-mentioned prior art. The technical solution of the present invention is simple and easy to operate, suitable for large-scale industrial production, and in line with the concept of social sustainable development. While endowing cellulose fibers with good flame-retardant performance, it can also ensure their excellent flame-retardant durability performance.

[0006] To achieve the above purpose, the present invention provides the following solutions:

[0007] One of the technical solutions of the present invention is a preparation method of a biomass blended flame-retardant cellulose fiber material, comprising the following steps:

[0008] (1) Dissolve a polyhydroxy biomass carbon source and phosphazene, and then add an alkaline reagent to carry out a substitution reaction. After the reaction is completed, a polyhydroxy biomass intumescent flame retardant is obtained;

[0009] (2) Prepare a cellulose spinning solution, add the polyhydroxy biomass intumescent flame retardant, and carry out defoaming treatment to obtain a flame-retardant cellulose spinning solution;

[0010] (3) Adopt a wet spinning process to spin the flame-retardant cellulose spinning solution to obtain the biomass blended flame-retardant cellulose fiber material.

[0011] Another technical solution of the present invention is the biomass blended flame-retardant cellulose fiber material prepared by the above preparation method.

[0012] Another technical solution of the present invention is the application of the biomass blended flame-retardant cellulose fiber material in the preparation of flame-retardant products.

[0013] Another technical solution of the present invention is a flame-retardant product comprising the biomass blended flame-retardant cellulose fiber material.

[0014] Based on the above technical solutions, the present invention has the following technical effects:

[0015] (1) Utilize a polyhydroxy biomass carbon source to construct an intumescent flame retardant, with wide raw material sources, green and environmentally friendly, meeting the concept of sustainable development;

[0016] (2) Through chemical modification of the polyhydroxy biomass carbon source, construct an intumescent flame retardant containing flame-retardant components such as phosphorus and nitrogen, which can fully exert the synergistic flame-retardant effect of the acid source, carbon source and gas source, with high flame-retardant efficiency, low addition amount, and can well retain the excellent properties of the original cellulose fiber; the polyhydroxy biomass intumescent flame retardant not only has a good P-N synergistic flame-retardant effect, but also the polyhydroxy structure is compatible with cellulose molecules and generates a large number of hydrogen bonds, greatly improving the compatibility and anti-migration performance of the flame retardant and the cellulose matrix. Finally, a durable flame-retardant cellulose fiber is obtained, and its limiting oxygen index value can reach up to 38.5%;

[0017] (3) The technical solution of the present invention is simple and easy to operate, with low cost and good modification effect, suitable for large-scale preparation. Detailed implementation mode

[0018] The various exemplary embodiments of the present invention will be described in detail. In the examples, unless otherwise specified, the methods are all conventional methods, and the reagents, unless otherwise specified, are all conventional commercially available reagents or reagents prepared by conventional methods. This detailed description should not be construed as a limitation of the present invention, but rather as a more detailed description of certain aspects, characteristics, and embodiments of the present invention.

[0019] It should be understood that the terms used in the present invention are only for describing specific embodiments and are not intended to limit the present invention. Additionally, for the numerical ranges in the present invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any intermediate value within any stated value or stated range, as well as each smaller range between any other stated value or intermediate value within the stated range, is also included in the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0020] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Although the present invention only describes preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the said documents. In case of conflict with any incorporated document, the content of this specification shall prevail.

[0021] Without departing from the scope or spirit of the present invention, various improvements and variations can be made to the specific embodiments of the present invention specification, which are obvious to those skilled in the art. Other embodiments obtained from the specification of the present invention are obvious to those skilled in the art. The specification and examples of the present invention are merely exemplary.

[0022] Regarding the use of "comprising", "including", "having", "containing", etc. herein, they are all open-ended terms, meaning including but not limited to.

[0023] The technical solutions of the present invention, unless otherwise specified, are all conventional solutions in the art, and the reagents or raw materials used, unless otherwise specified, are all purchased from commercial channels or have been made public.

[0024] The embodiments of the present invention provide a preparation method of a biomass blended flame-retardant cellulose fiber material, comprising the following steps:

[0025] (1) Dissolve the polyhydroxy biomass carbon source and phosphazene, then add an alkaline reagent to carry out a substitution reaction, and obtain a polyhydroxy biomass intumescent flame retardant after the reaction is completed;

[0026] (2) Prepare a cellulose spinning solution, add the polyhydroxy biomass intumescent flame retardant, and perform defoaming treatment to obtain a flame-retardant cellulose spinning solution;

[0027] (3) Using a wet spinning process, spin the flame-retardant cellulose spinning solution to obtain the biomass blend flame-retardant cellulose fiber material.

[0028] In some specific embodiments, the substitution reaction is carried out in an organic solvent, and the organic solvent is selected from at least one of chloroform, dichloromethane, N,N-dimethylformamide, tetrahydrofuran, and acetonitrile; the present invention has no special requirements for the amount of the organic solvent, as long as the substitution reaction can proceed smoothly.

[0029] In some specific embodiments, the polyhydroxy biomass carbon source is selected from at least one of cyclodextrin, starch, cellulose, alginic acid, tea polyphenols, tannic acid, and lignin; the phosphazene is selected from at least one of hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene, and polyphosphazene chloride; the molar ratio of the polyhydroxy biomass carbon source to the phosphazene is 1:(1-3); preferably 1:(1-1.5); more preferably 1:(1.2-1.4).

[0030] In some specific embodiments, the temperature of the substitution reaction is 40-150 °C, preferably 60-120 °C; the time is 4-12 h, preferably 6-10 h.

[0031] In some specific embodiments, the basic reagent is selected from at least one of triethylamine, K 2 CO 3 、Cs 2 CO 3 and NaH; the molar ratio of the basic reagent to the hydroxyl group in the polyhydroxy biomass carbon source is (1.2-1.5):1. The basic reagent acts as an acid-binding agent and a catalyst.

[0032] In some specific embodiments, the method for preparing the cellulose spinning solution is: dissolving cellulose in an NMMO aqueous solution to obtain the cellulose spinning solution;

[0033] The concentration of the NMMO aqueous solution is 85 wt% - 87 wt%; the mass ratio of cellulose to the NMMO aqueous solution is (8-15):100.

[0034] In some specific embodiments, the mass ratio of the polyhydroxy biomass intumescent flame retardant to the cellulose in the cellulose spinning solution is 1:(2-10), preferably 1:(2-5), more preferably 1:(3-4).

[0035] The embodiments of the present invention also provide the biomass blend flame-retardant cellulose fiber material prepared by the above preparation method.

[0036] The embodiments of the present invention also provide the application of the biomass blended flame-retardant cellulose fiber material in the preparation of flame-retardant products.

[0037] The embodiments of the present invention also provide a flame-retardant product, including the biomass blended flame-retardant cellulose fiber material.

[0038] Example 1

[0039] (1) Preparation of the polyhydroxy biomass intumescent flame retardant: Dissolve 113 g of cyclodextrin and 84 g of hexachlorocyclotriphosphazene in a 500 mL reactor containing N,N-dimethylformamide (DMF), start stirring and heating, control the reaction temperature at 40 °C, and then gradually add 34 mL of triethylamine to the reaction system drop by drop through a constant pressure dropping funnel. After the addition is completed, raise the reaction temperature to 70 °C and continue the reaction for 8 h; after the reaction is completed, wash with anhydrous ethanol and deionized water multiple times, and obtain the polyhydroxy biomass intumescent flame retardant after vacuum filtration and drying.

[0040] (2) Preparation of the flame-retardant cellulose spinning solution: Use vacuum distillation to increase the concentration of commercially available 50 wt% N-methyl morpholine-N-oxide (NMMO) aqueous solution to 85 wt% for dissolving cellulose pulp; cellulose accounts for 8 wt% of the NMMO aqueous solution system; add the polyhydroxy biomass intumescent flame retardant prepared in step (1) to the above-mentioned cellulose spinning solution, where the polyhydroxy biomass intumescent flame retardant accounts for 15 wt% of the cellulose mass. After uniform mixing and degassing treatment, it is reserved for standby.

[0041] (3) Spinning of the flame-retardant cellulose fiber: Adopt the wet spinning process, spray the spinning solution through the spinneret holes into the coagulation bath to obtain the nascent fiber, the spinning speed is 60 m / min and the air gap length is 5 cm, and then obtain the flame-retardant cellulose fiber through stretching, washing, drying and winding.

[0042] Test the flame retardancy of the biomass blended flame-retardant cellulose fiber according to the method in "GB / T 5454-1997 Textiles - Test method for burning performance - Oxygen index method". The results show that the limiting oxygen index (LOI) value of the flame-retardant fiber is 27.2%.

[0043] Example 2

[0044] (1) Preparation of polyhydroxy biomass intumescent flame retardant: 170 g of tannic acid and 150 g of hexachlorocyclotriphosphazene were dissolved in a 500 mL reactor containing DMF. Stirring was started and the mixture was heated, with the reaction temperature controlled at 40 °C. Then, 60 mL of triethylamine was gradually added dropwise to the reaction system through a constant pressure dropping funnel. After the addition was complete, the reaction temperature was raised to 80 °C and the reaction was continued for 10 h. After the reaction ended, it was washed repeatedly with absolute ethanol and deionized water, and then obtained the polyhydroxy biomass intumescent flame retardant after vacuum filtration and drying.

[0045] (2) Preparation of flame retardant cellulose spinning solution: The concentration of commercially available 50 wt% NMMO aqueous solution was increased to 85 wt% by means of vacuum distillation to dissolve cellulose pulp; cellulose accounted for 10 wt% of the NMMO aqueous solution system. The polyhydroxy biomass intumescent flame retardant prepared in step (1) was added to the above-mentioned cellulose spinning solution, where the polyhydroxy biomass intumescent flame retardant accounted for 20 wt% of the cellulose mass. After uniform mixing and degassing treatment, it was reserved for use.

[0046] (3) Spinning of flame retardant cellulose fiber: Using the wet spinning process, the spinning solution was ejected through a spinneret into a coagulation bath to obtain a nascent fiber, with a spinning speed of 90 m / min and an air gap length of 5 cm. Then, it was drawn, washed, dried, and wound to obtain the flame retardant cellulose fiber.

[0047] According to the method in "GB / T 5454-1997 Textiles - Test method for burning performance - Oxygen index method", the flame retardancy of the biomass blended flame retardant cellulose fiber was tested. The results showed that the limiting oxygen index (LOI) value of the flame retardant fiber was up to 33.4%.

[0048] Example 3

[0049] (1) Preparation of polyhydroxy biomass intumescent flame retardant: 120 g of lignin and 80 g of hexachlorocyclotriphosphazene were dissolved in a 500 mL reactor containing DMF. Stirring was started and the mixture was heated, with the reaction temperature controlled at 40 °C. Then, 60 mL of triethylamine was gradually added dropwise to the reaction system through a constant pressure dropping funnel. After the addition was complete, the reaction temperature was raised to 90 °C and the reaction was continued for 12 h. After the reaction ended, it was washed repeatedly with absolute ethanol and deionized water, and then obtained the polyhydroxy biomass intumescent flame retardant after vacuum filtration and drying.

[0050] (2) Preparation of flame retardant cellulose spinning solution: The concentration of commercially available 50 wt% NMMO aqueous solution was increased to 85 wt% by means of vacuum distillation to dissolve cellulose pulp; cellulose accounted for 12 wt% of the NMMO aqueous solution system. The polyhydroxy biomass flame retardant prepared in step (1) was added to the above-mentioned cellulose spinning solution, where the polyhydroxy biomass intumescent flame retardant accounted for 25 wt% of the cellulose mass. After uniform mixing and degassing treatment, it was reserved for use.

[0051] (3) Spinning of flame-retardant cellulose fibers: Using the wet spinning process, the spinning solution is ejected through the spinneret holes into the coagulation bath to obtain the nascent fibers. The spinning speed is 110 m / min and the air gap length is 5 cm. Then, through drawing, washing, drying, and winding, the flame-retardant cellulose fibers are obtained.

[0052] The flame retardancy of the biomass blended flame-retardant cellulose fibers was tested according to the method in "GB / T 5454-1997 Textiles - Test method for burning performance - Oxygen index method". The results show that the limiting oxygen index (LOI) value of the flame-retardant fibers is up to 38.5%.

[0053] Comparative Example 1

[0054] (1) Preparation of cellulose spinning solution: The concentration of commercially available 50 wt% NMMO aqueous solution was increased to 85 wt% by vacuum distillation to dissolve cellulose pulp; cellulose accounted for 10 wt% of the NMMO aqueous solution system.

[0055] (2) Spinning of cellulose fibers: Using the wet spinning process, the spinning solution is ejected through the spinneret holes into the coagulation bath to obtain the nascent fibers. The spinning speed is 90 m / min and the air gap length is 5 cm. Then, through drawing, washing, drying, and winding, the cellulose fibers are obtained.

[0056] The flame retardancy of the cellulose fibers was tested according to the method in "GB / T 5454-1997 Textiles - Test method for burning performance - Oxygen index method". The results show that the limiting oxygen index (LOI) value of the flame-retardant fibers is up to 18.6%.

[0057] The properties of the biomass blended flame-retardant cellulose fibers prepared in Examples 1 to 3 and Comparative Example 1 are shown in Table 1.

[0058] Table 1 Properties of biomass blended flame-retardant cellulose fibers with different contents

[0059] Project Name Example 1 Example 2 Example 3 Comparative Example 1 Flame Retardant Content 15wt% 20wt% 25wt% 0 Mechanical Strength (cN / dtex) 3.06 2.86 2.73 3.15 LOI (%) 27.2％ 33.4％ 38.5％ 18.6％ LOI (%) after 30 Washings 25.9％ 28.6％ 31.4％ 18.6％

[0060] As can be seen from Table 1, compared with Comparative Example 1, the addition of the flame retardant in the examples leads to a decrease in the mechanical properties of the fibers. And as the content of the flame retardant increases, its mechanical properties decrease, but are still higher than 2.70 cN / dtex. At the same time, as the content of the flame retardant increases, the LOI value of the fibers shows an obvious upward trend. And after 30 washes, its LOI value decreases to some extent, but is still higher than the LOI value of the fibers in the comparative example, indicating that the biomass blended flame-retardant cellulose fibers of the present invention have good flame retardant durability.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all implementation manners here. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a biomass blended flame-retardant cellulose fiber material, characterized in that: The following steps are involved: (1) dissolving a polyhydroxy biomass carbon source and phosphazene, then adding an alkaline reagent to carry out a substitution reaction, and after the reaction is completed, obtaining a polyhydroxy biomass intumescent flame retardant; The polyhydroxy biomass carbon source is selected from at least one of cyclodextrin, starch, cellulose, alginic acid, tea polyphenols, tannic acid and lignin; the phosphazene is selected from at least one of hexachlorocyclotriphosphazene, octachlorocyclotetraphosphazene and polychlorinated phosphazene; the molar ratio of the polyhydroxy biomass carbon source to the phosphazene is 1:(1-3); (2) preparing a cellulose spinning solution, adding the polyhydroxy biomass intumescent flame retardant, and performing a defoaming treatment to obtain a flame-retardant cellulose spinning solution; the mass ratio of the polyhydroxy biomass intumescent flame retardant to the cellulose in the cellulose spinning solution is 1:(2-10); (3) The flame-retardant cellulose spinning solution is spun by a wet spinning process to obtain the biomass-blended flame-retardant cellulose fiber material.

2. The preparation method according to claim 1, characterized in that: The temperature of the substitution reaction is 40-150° C. and the time is 4-12 hours.

3. The preparation method according to claim 1, characterized in that: The alkaline reagent is selected from at least one of triethylamine, K2CO3, Cs2CO3 and NaH; the molar ratio of the alkaline reagent to the hydroxyl group in the polyhydroxy biomass carbon source is (1.2-1.5):

1.

4. The preparation method according to claim 1, characterized in that: The method for preparing the cellulose spinning solution is: dissolving cellulose in an NMMO aqueous solution to obtain the cellulose spinning solution; The concentration of the NMMO aqueous solution is 85wt%-87wt%; the mass ratio of the cellulose to the NMMO aqueous solution is (8-15):

100.

5. The biomass blended flame-retardant cellulose fiber material prepared by the preparation method according to any one of claims 1 to 4.

6. Use of the biomass blended flame-retardant cellulose fiber material as claimed in claim 5 in the preparation of flame-retardant products.

7. A flame retardant product, characterized in that: Comprising the biomass blended flame-retardant cellulose fiber material as described in claim 5.