Biomass blended flame-retardant cellulose fiber material as well as preparation method and application thereof

Abstract

The invention discloses a biomass blended flame-retardant cellulose fiber material as well as a preparation method and application thereof, and belongs to the technical field of cellulose fiber material preparation. Comprising the following steps: (1) dissolving a polyhydroxy biomass carbon source and phosphazene, then adding an alkaline reagent, and carrying out substitution reaction to obtain 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 defoaming treatment to obtain a flame-retardant cellulose spinning solution; and (3) spinning the flame-retardant cellulose spinning solution by adopting a wet spinning process to obtain the biomass blended flame-retardant cellulose fiber material. The intumescent flame retardant containing flame-retardant components such as phosphorus and nitrogen is constructed through chemical modification of a polyhydroxy biomass carbon source, the synergistic flame-retardant effect of an acid source, the carbon source and a gas source can be fully exerted, the flame-retardant efficiency is high, the addition amount is small, and the excellent performance of original cellulose fibers can be well reserved.

Description

Technical Field

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

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

[0003] To date, halogen flame retardants have been widely used due to their low price and high flame retardant performance. For example, polybrominated diphenyl ethers have been widely used in flame retardant modification of textiles, but they release pollutants that are permanently harmful to humans and the natural environment. N-hydroxymethyl-3-(dimethoxyphosphonyl) propionamide (Pyrovatex CP) and ammonia-cured, 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 groups on the side groups, these two flame retardants will inevitably degrade and release formaldehyde during processing and use, and formaldehyde is considered to be a serious carcinogen. Therefore, there is an urgent need to develop sustainable and environmentally friendly flame retardants.

[0004] In recent years, the development of high-performance materials using biomass resources to replace petroleum-derived chemicals has been a key direction of sustainable development strategies. It is worth noting that the polyhydroxy structures of natural sugar compounds and polyphenol compounds, such as cyclodextrin and starch, are highly similar to cellulose molecules. Therefore, based on the principle of "similar compatibility of molecular structures", biomass intumescent flame retardants designed with polyhydroxy biomass molecules that are adapted to the cellulose molecular structure have good structural advantages. However, there are currently no reports on the relevant technology for 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 and its preparation method and application 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 sustainable development of society. While giving cellulose fibers good flame retardant properties, it can also ensure their excellent flame retardant and durable properties.

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

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

[0008] (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;

[0009] (2) preparing a cellulose spinning solution, adding the polyhydroxy biomass intumescent flame retardant, and performing a degassing treatment to obtain a flame-retardant cellulose spinning solution;

[0010] (3) The flame-retardant cellulose spinning solution is spun by a wet spinning process to obtain the biomass-blended flame-retardant cellulose fiber material.

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

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

[0013] A fourth 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 solution, the present invention has the following technical effects:

[0015] (1) Using polyhydroxy biomass carbon sources to construct intumescent flame retardants has a wide range of raw material sources, is green and environmentally friendly, and conforms to the concept of sustainable development;

[0016] (2) By chemically modifying 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, with high flame retardant efficiency and small 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 PN synergistic flame retardant effect, but also the polyhydroxy structure is compatible with cellulose molecules and produces a large number of hydrogen bonds, which greatly improves 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) This technical solution is simple and easy to operate, low in cost, good in modification effect, and suitable for large-scale preparation. DETAILED DESCRIPTION

[0018] Now, various exemplary embodiments of the present invention are described in detail. The methods in the examples are conventional methods unless otherwise specified, and the reagents used are conventional commercially available reagents or reagents prepared by conventional methods unless otherwise specified. This detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, features and embodiments of the present invention.

[0019] It should be understood that the terms described in the present invention are only for describing a particular embodiment and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0020] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only 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 associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0021] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0022] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

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

[0024] The embodiment of the present invention provides a method for preparing a biomass blended flame-retardant cellulose fiber material, comprising the following steps:

[0025] (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;

[0026] (2) preparing a cellulose spinning solution, adding the polyhydroxy biomass intumescent flame retardant, and performing a degassing treatment to obtain a flame-retardant cellulose spinning solution;

[0027] (3) The flame-retardant cellulose spinning solution is spun by a wet spinning process to obtain the biomass-blended 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 on 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, alginate, 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); 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 to 150° C., preferably 60 to 120° C.; the time is 4 to 12 hours, preferably 6 to 10 hours.

[0031] In some specific embodiments, the alkaline agent is selected from at least one of triethylamine, K2CO3, Cs2CO3 and NaH; the molar ratio of the alkaline agent to the hydroxyl group in the polyhydroxy biomass carbon source is (1.2-1.5): 1. The alkaline agent 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 85wt%-87wt%; the mass ratio of the 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), and more preferably 1:(3-4).

[0035] The embodiment of the present invention also provides a biomass blended flame-retardant cellulose fiber material prepared by the preparation method.

[0036] The embodiment of the present invention also provides the use of the biomass blended flame-retardant cellulose fiber material in the preparation of flame-retardant products.

[0037] An embodiment of the present invention further provides a flame retardant product, comprising the biomass blended flame retardant cellulose fiber material.

[0038] Example 1

[0039] (1) Preparation of polyhydroxy biomass intumescent flame retardant: 113 g of cyclodextrin and 84 g of hexachlorocyclotriphosphazene were dissolved in a 500 mL reactor containing N,N-dimethylformamide (DMF), stirred and heated, and the reaction temperature was controlled to 40°C. Then, 34 mL of triethylamine was added dropwise to the reaction system through a constant pressure dropping funnel. After the addition was completed, the reaction temperature was increased to 70°C and the reaction was continued for 8 hours. After the reaction was completed, it was washed with anhydrous ethanol and deionized water several times, and after reduced pressure filtration and drying, a polyhydroxy biomass intumescent flame retardant was obtained.

[0040] (2) Preparation of flame-retardant cellulose spinning solution: The concentration of a commercially available 50 wt% N-methylmorpholine-N-oxide (NMMO) aqueous solution is increased to 85 wt% by vacuum distillation to dissolve cellulose pulp; cellulose accounts for 8 wt% of the NMMO aqueous solution system; the polyhydroxy biomass intumescent flame retardant prepared in step (1) is added to the above-mentioned cellulose spinning solution, wherein the polyhydroxy biomass intumescent flame retardant accounts for 15 wt% of the cellulose mass, and after being uniformly mixed and defoamed, it is set aside for use.

[0041] (3) Spinning of flame-retardant cellulose fibers: The spinning solution is ejected through a spinneret into a coagulation bath to obtain primary fibers using a wet spinning process. The spinning speed is 60 m / min and the air gap length is 5 cm. The fibers are then stretched, washed, dried, and wound to obtain flame-retardant cellulose fibers.

[0042] The flame retardancy of biomass blended flame retardant cellulose fibers was tested according to the method in "GB / T 5454-1997 Textile Combustion Performance Test Oxygen Index Method". The results showed that the limiting oxygen index (LOI) value of the flame retardant fiber was 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, stirred and heated, and the reaction temperature was controlled to 40°C. Then, 60 mL of triethylamine was added dropwise to the reaction system through a constant pressure dropping funnel. After the addition was completed, the reaction temperature was increased to 80°C and the reaction was continued for 10 hours. After the reaction was completed, it was washed with anhydrous ethanol and deionized water for multiple times, and after reduced pressure filtration and drying, a polyhydroxy biomass intumescent flame retardant was obtained.

[0045] (2) Preparation of flame-retardant cellulose spinning solution: The concentration of a commercially available 50 wt% NMMO aqueous solution is increased to 85 wt% by vacuum distillation to dissolve cellulose pulp; cellulose accounts for 10 wt% of the NMMO aqueous solution system; the polyhydroxy biomass intumescent flame retardant prepared in step (1) is added to the above-mentioned cellulose spinning solution, wherein the polyhydroxy biomass intumescent flame retardant accounts for 20 wt% of the cellulose mass, and after being uniformly mixed and defoamed, it is set aside for later use.

[0046] (3) Spinning of flame-retardant cellulose fibers: The spinning solution is ejected through a spinneret into a coagulation bath to obtain primary fibers using a wet spinning process. The spinning speed is 90 m / min and the air gap length is 5 cm. The fibers are then stretched, washed, dried, and wound to obtain flame-retardant cellulose fibers.

[0047] The flame retardancy of biomass blended flame retardant cellulose fibers was tested according to the method in "GB / T 5454-1997 Textile Combustion Performance Test Oxygen Index Method". The results showed that the limiting oxygen index (LOI) value of the flame retardant fiber was as high as 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, stirred and heated, and the reaction temperature was controlled to 40°C. Then, 60 mL of triethylamine was added dropwise to the reaction system through a constant pressure dropping funnel. After the addition was completed, the reaction temperature was increased to 90°C and the reaction was continued for 12 hours. After the reaction was completed, it was washed with anhydrous ethanol and deionized water several times, and after reduced pressure filtration and drying, a polyhydroxy biomass intumescent flame retardant was obtained.

[0050] (2) Preparation of flame-retardant cellulose spinning solution: The concentration of a commercially available 50 wt% NMMO aqueous solution is increased to 85 wt% by vacuum distillation to dissolve cellulose pulp; cellulose accounts for 12 wt% of the NMMO aqueous solution system; the polyhydroxy biomass flame retardant prepared in step (1) is added to the above-mentioned cellulose spinning solution, wherein the polyhydroxy biomass intumescent flame retardant accounts for 25 wt% of the cellulose mass, and after being uniformly mixed and defoamed, it is set aside for later use.

[0051] (3) Spinning of flame-retardant cellulose fibers: A wet spinning process is used to spray the spinning solution through a spinneret into a coagulation bath to obtain primary fibers. The spinning speed is 110 m / min and the air gap length is 5 cm. The fibers are then stretched, washed, dried, and wound to obtain flame-retardant cellulose fibers.

[0052] The flame retardancy of biomass blended flame retardant cellulose fibers was tested according to the method in "GB / T 5454-1997 Textile Combustion Performance Test Oxygen Index Method". The results showed that the limiting oxygen index (LOI) value of the flame retardant fiber was as high as 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: A wet spinning process is used to spray the spinning solution through a spinneret into a coagulation bath to obtain primary fibers. The spinning speed is 90 m / min and the air gap length is 5 cm. The cellulose fibers are then drawn, washed, dried, and wound.

[0056] The flame retardancy of cellulose fibers was tested according to the method in GB / T 5454-1997 Textile Combustion Performance Test - Oxygen Index Method. The results showed that the limiting oxygen index (LOI) value of the flame retardant fibers was as high as 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 Performance 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 washes (%) 25.9％ 28.6％ 31.4％ 18.6％

[0060] It can be seen from Table 1 that compared with Comparative Example 1, the addition of flame retardant in the embodiment leads to a decrease in the mechanical properties of the fiber, and with the increase of the flame retardant content, the mechanical properties decrease, but are still higher than 2.70 cN / dtex. At the same time, with the increase of the flame retardant content, the LOI value of the fiber shows an obvious upward trend, and after 30 washes, the LOI value decreases, but is still higher than the LOI value of the fiber in the comparative example, indicating that the biomass blended flame retardant cellulose fiber of the present invention has good flame retardant durability.

[0061] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technical users in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in 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; (2) preparing a cellulose spinning solution, adding the polyhydroxy biomass intumescent flame retardant, and performing a degassing treatment to obtain a flame-retardant cellulose spinning solution; (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 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).

3. 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.

4. 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.

5. 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.

6. The preparation method according to claim 1, characterized in that: The mass ratio of the polyhydroxy biomass intumescent flame retardant to the cellulose in the cellulose spinning solution is 1:(2-10).

7. The biomass blended flame-retardant cellulose fiber material prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the biomass blended flame-retardant cellulose fiber material as claimed in claim 7 in the preparation of flame-retardant products.

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