Flame-retardant modified cellulose PA56 composite fiber material as well as preparation method and application thereof
By introducing phytate derivatives and cellulose into bio-based PA56 fiber materials for in-situ flame retardant modification, a multi-element synergistic flame retardant network is formed, which solves the problems of poor cohesion and low flame retardant rating of bio-based PA56 fiber materials, and achieves high-efficiency flame retardancy and improved thermal stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 福建恒捷实业有限公司
- Filing Date
- 2026-02-06
- Publication Date
- 2026-05-12
AI Technical Summary
Bio-based PA56 fiber materials suffer from poor cohesion, are prone to static electricity and fuzz, have poor spinnability, low flame retardancy, and insufficient thermal safety, which limits their application scenarios and scope.
Phytate derivatives were prepared by esterification reaction, and then combined with polyethylene glycol and hydroxyethyl acrylate. The mixture was added to cellulose spinning solution for in-situ flame retardant modification and melt-blended with PA56 to form a flame retardant modified cellulose PA56 composite material. The cross-linking network and hydrogen bonding of P, N and Si elements were used to achieve multi-element synergistic flame retardancy.
It improves the compatibility and flame retardant properties of cellulose materials with PA56, maintains the physical properties of polyamide, forms a dense char layer and a foamy coke layer, slows down the combustion rate, and enhances the flame retardant effect and thermal stability of the material.
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Figure CN122013361A_ABST
Abstract
Description
Technical Field
[0001] A flame-retardant modified cellulose PA56 composite fiber material, its preparation method and application Background Technology
[0002] With increasingly stringent carbon emission reduction policies, the research and development of bio-based PA56 has attracted much attention and become one of the hot spots of competition among domestic and foreign textile giants. Bio-based polyamide 56 is a new type of bio-based fiber made from crops, trees and other plants and their residues and contents through biological, chemical and physical means. It has excellent mechanical properties and biodegradability.
[0003] However, PA56 fibers have poor cohesion, which makes them prone to static electricity and fuzz when spun into yarn, resulting in poor spinnability. At the same time, the limiting oxygen index (LOI) of unmodified PA56 is only 20%~22%, and its flame retardancy rating can only reach UL 94 V-2, making it a flammable material. Therefore, the thermal safety of bio-based PA56 has become one of the main factors restricting its application scenarios and scope.
[0004] With the development of bio-based PA56, the demand for flame-retardant properties is increasing, which has driven research into bio-based flame retardants. Currently, common bio-based flame retardants include phytic acid, chitosan, lignin, cyclodextrin, and alginate. However, the large-scale application of most bio-based flame retardants is still limited by technical bottlenecks such as insufficient thermal stability, making it difficult to comprehensively improve the flame retardancy and thermal stability of bio-based PA56. Summary of the Invention
[0005] The technical problem to be solved by this invention is to provide a flame-retardant modified cellulose PA56 composite fiber material, its preparation method and application. The prepared textile material has good flame retardancy and thermal stability, and has broad application prospects.
[0006] This invention is implemented as follows: This invention first provides a method for preparing a flame-retardant modified cellulose PA56 composite fiber material, comprising the following steps: (1) Phytic acid was reacted with polyethylene glycol monomethyl ether and hydroxyethyl acrylate to prepare phytate derivatives modified with polyethylene glycol and acrylate groups by esterification reaction; (2) The prepared phytate derivative and diethylenetriaminepropylmethyldimethoxysilane were added to the cellulose spinning solution to perform in-situ flame retardant modification on the cellulose. (3) The flame-retardant modified cellulose obtained in step (2) is melt-blended with PA56 to prepare a flame-retardant modified cellulose PA56 composite material, and then the flame-retardant modified cellulose PA56 composite fiber material is prepared by melt spinning.
[0007] Further, the molecular weight of the polyethylene glycol monomethyl ether in step (1) is 1000, 2000, 5000 or 10000.
[0008] Furthermore, in step (1), the molar ratio of phytic acid to polyethylene glycol monomethyl ether is 1:1 to 1:6.
[0009] Furthermore, in step (1), the molar ratio of phytic acid to hydroxyethyl acrylate is 1:11 to 1:6.
[0010] Further, the proportions of each component in step (2) are: 5 wt%~25 wt% phytate derivative, 75 wt%~95 wt% cellulose spinning solution, and the total mass ratio of the above is 100%.
[0011] Furthermore, 6 mol of double bonds in the phytate derivative need to be supplemented with 1 mol of diethylenetriaminepropylmethyldimethoxysilane.
[0012] Furthermore, the raw materials for preparing the flame-retardant modified cellulose PA56 composite material in step (3) include, by mass, 100 parts PA56, 10-25 parts flame-retardant modified cellulose, and 3-5 parts compatibilizer.
[0013] This invention also provides a flame-retardant modified cellulose PA56 composite fiber material obtained by the aforementioned preparation method. This flame retardant possesses both solid-phase and gas-phase flame-retardant mechanisms. Through amino-double bond reactions, it immobilizes the three flame-retardant elements P, N, and Si within the cross-linked network, overcoming problems such as volatility, agglomeration, migration, and leaching of flame retardants, thus exhibiting long-lasting flame-retardant properties. Simultaneously, the hydrogen bonding between the network and cellulose improves the compatibility between the flame-retardant cellulose material and PA56, enhancing the flame-retardant properties of the polyamide while better preserving its physical and mechanical properties. Specifically, the pyrolysis of phytic acid nuclei generates P-containing free radicals. These free radicals not only interrupt the polymer combustion chain reaction and exothermic process, thus slowing combustion, but also promote the carbonization of the polymer into a dense, flame-retardant char layer, terminating further combustion. The N cross-linking sites formed through the amino-double bond reaction release large amounts of inert gases such as N2 and NH3 upon heating, diluting the oxygen concentration in the combustion zone and the concentration of combustible gases generated by the thermal decomposition of the polyamide, thereby reducing the degree of polyamide combustion. Furthermore, when compounded with phosphorus-based flame retardants, the flame retardant system promotes the formation of a foam-like char layer, which, when covering the polyamide surface, acts as a thermal and oxygen barrier. The introduced silicon migrates to the matrix surface during combustion, forming a dense, glassy char layer. This char layer slows or prevents the escape of flammable gases and heat transfer, thus reducing the combustion rate and heat release rate, thereby hindering or terminating the material's combustion (this is also the solidified phase flame retardant mechanism). Therefore, this flame retardant possesses multiple flame retardant properties and compatible functional groups (introduced ethoxy groups and cellulose), achieving efficient integration of multiple elements (P, N, and Si) and intramolecular synergistic flame retardancy.
[0014] Finally, this invention provides the application of the flame-retardant modified cellulose PA56 composite fiber material in the preparation of biomass-based flame-retardant functional nylon fabric. The flame-retardant modified cellulose PA56 composite fiber material is subjected to stretching, false-twist, heat setting, oiling, winding, and spinning processes to obtain biomass-based flame-retardant functional nylon fabric.
[0015] This invention has the following advantages: It improves the compatibility between cellulose materials and PA56 through flame-retardant modification, enhancing the flame-retardant properties of polyamide while better preserving the physical and mechanical properties of the polyamide itself. This results in textile materials with better flame-retardant effects and environmental performance, while also improving the thermal stability of the fiber materials. Attached Figure Description
[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0017] Figure 1 This is the NMR result of the phytate derivative. Detailed Implementation
[0018] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings and specific embodiments. Unless otherwise specified in the embodiments, conditions are performed according to conventional conditions or conditions recommended by the manufacturer. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.
[0019] A method for preparing a flame-retardant modified cellulose PA56 composite fiber material includes the following steps: (1) Preparation method of bio-based flame retardant: 0.04 mol phytic acid, 0.16 mol hydroxyethyl acrylate, 0.08 mol polyethylene glycol monomethyl ether 1000, and 1% DMAP (4-(dimethylamino)pyridine) catalyst were dissolved in a 100 mL acetone flask and stirred in an ice-water bath for 30 min. 0.05 mol DCC (dicyclohexylcarbodiimide) was added to the mixture, and stirring was continued for 2 h. After filtration, the filtrate was collected, the solvent was removed, ethyl acetate was added, and the filtrate was collected again after filtration. The filtrate was washed successively with 0.1 mol / L hydrochloric acid, saturated sodium bicarbonate solution, and saturated sodium chloride solution. Anhydrous magnesium sulfate was added and dried for 30 min, and then filtered to remove the solvent from the filtrate to obtain the solid phytate derivative. NMR results are shown in […]. Figure 1 .
[0020] The amounts of 0.16 mol hydroxyethyl acrylate and 0.08 mol polyethylene glycol monomethyl ether are adjustable, as described above. The higher the amount of hydroxyethyl acrylate, the higher the content of ethylenetriaminepropylmethyldimethoxysilane in subsequent step two.
[0021] (2) Cellulose compounding: The prepared phytate derivative and diethylenetriaminepropylmethyldimethoxysilane were added to the bacterial cellulose spinning solution and heated and stirred at 40°C for 24 h to perform in-situ flame retardant modification of cellulose. The solvent was removed to obtain a bio-based flame retardant compounded with cellulose.
[0022] The molar ratio of phytate derivative to diethylenetriamine diethylenetriaminepropylmethyldimethoxysilane is 1.5:1, the amount of phytate derivative added is 17wt%, and the amount of bacterial cellulose spinning solution added is 83wt%.
[0023] (3) The cellulose / flame retardant compound prepared in step (2) is melt-blended with PA56 and compatibilizer (the specific ratio is shown in Table 1). The temperature is 40-60℃ higher than the melting point of PA56, the blending time is 5-10 minutes, and the flame retardant modified cellulose PA56 composite material is obtained by nozzle extrusion, water cooling, granulation and cutting.
[0024] (4) Flame-retardant modified cellulose PA56 composite material is obtained by melt spinning.
[0025] Table 1 Examples with different raw material ratios
[0026] In Examples 1 and 2, the cellulose / flame retardant compound was the product of polyethylene glycol monomethyl ether 1000 reaction, and in Example 3, it was polyethylene glycol monomethyl ether 5000.
[0027] (5) Performance testing: a. Prepare standard test strips for flame retardant and mechanical performance testing of the test samples, and conduct UL94 vertical burning test (refer to GB / T2406-2008) and limiting oxygen index (LOI) test (refer to GB / T2406-93) respectively.
[0028] b. UL94 Vertical Burning Test: The test specimen (1.6 mm thick) is placed vertically at a certain flame height and ignited several times at regular intervals. Its flammability is evaluated based on the ignition of the specimen, the duration of burning, and whether the igniter used to receive it can be ignited.
[0029] c. Limiting Oxygen Index (LOI) Test: Under an oxygen-nitrogen mixed atmosphere, the test specimen is vertically mounted in the specimen holder and ignited at the top. The oxygen concentration in the mixed gas is adjusted until the flame front reaches the specimen mark, and the material's LOI value is calculated by combining the average of three test results.
[0030] d. Thermal stability test: Take 5-10 mg of samples from Examples 1-3 and Comparative Examples 1-3, and determine the thermal decomposition temperature of the materials using an SDTQ 600 thermogravimetric analyzer (TA, USA) in an air atmosphere. Perform three parallel tests and take the average value. The heating rate was 10℃ / min, and the temperature range was 50-700℃.
[0031] Table 2 Performance of different embodiments
[0032] Where T1 is the temperature at which the test sample loses 5 wt% of its thermal weight.
[0033] As shown in Table 2, Examples 2 and 3 showed the best performance in terms of flame retardancy and thermal stability, indicating that the cellulose / flame retardant compound can effectively enhance the limiting oxygen index and combustion performance of PA56. The hydrogen bonding between the compound and the polyamide material increased the thermal stability of the composite material.
[0034] While specific embodiments of the present invention have been described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and not intended to limit the scope of the present invention. Equivalent modifications and variations made by those skilled in the art in accordance with the spirit of the present invention should be covered within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a flame-retardant modified cellulose PA56 composite fiber material, characterized in that: Includes the following steps: (1) Phytic acid was reacted with polyethylene glycol monomethyl ether and hydroxyethyl acrylate to prepare phytate derivatives modified with polyethylene glycol and acrylate groups by esterification reaction; (2) The prepared phytate derivative and diethylenetriaminepropylmethyldimethoxysilane were added to the cellulose spinning solution to perform in-situ flame retardant modification on the cellulose. (3) The flame-retardant modified cellulose obtained in step (2) is melt-blended with PA56 to prepare a flame-retardant modified cellulose PA56 composite material, and then the flame-retardant modified cellulose PA56 composite fiber material is prepared by melt spinning.
2. The preparation method according to claim 1, characterized in that: The molecular weight of the polyethylene glycol monomethyl ether in step (1) is 1000, 2000, 5000 or 10000.
3. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of phytic acid to polyethylene glycol monomethyl ether is 1:1 to 1:
6.
4. The preparation method according to claim 1, characterized in that: In step (1), the molar ratio of phytic acid to hydroxyethyl acrylate is 1:11 to 1:
6.
5. The preparation method according to claim 1, characterized in that: The proportions of each component in step (2) are: 5 wt%~25 wt% phytate derivative, 75 wt%~95 wt% cellulose spinning solution, and the total mass ratio of the above is 100%.
6. The preparation method according to claim 5, characterized in that: The phytate derivative requires the addition of 1 mol of diethylenetriaminepropylmethyldimethoxysilane to 6 mol of double bonds.
7. The preparation method according to claim 1, characterized in that: The raw materials for preparing the flame-retardant modified cellulose PA56 composite material in step (3) include, by mass parts: 100 parts PA56, 10-25 parts flame-retardant modified cellulose, and 3-5 parts compatibilizer.
8. A flame-retardant modified cellulose PA56 composite fiber material obtained by the preparation method according to any one of claims 1-7.
9. The application of the flame-retardant modified cellulose PA56 composite fiber material as described in claim 8 in the preparation of biomass-based flame-retardant functional nylon fabric.