Flame-retardant polyacrylonitrile fiber and preparation method thereof
阅读说明：本技术 阻燃聚丙烯腈纤维及其制备方法 (Flame-retardant polyacrylonitrile fiber and preparation method thereof ) 是由 董雪 周勤灼 沈志刚 李磊 于 2020-07-01 设计创作，主要内容包括：本发明提供了一种阻燃聚丙烯腈纤维及其制备方法,本发明提供的阻燃聚丙烯腈纤维包括聚丙烯腈纤维和助燃剂,其中所述助燃剂为次磷酸盐和三聚氰胺氰尿酸盐。本发明的阻燃聚丙烯腈纤维所需的原料均低毒或无毒,且工艺简单,污染低,适合大规模开发与利用,是一种真正环境友好的绿色高分子材料；并且本发明提供的阻燃剂具有磷-氮协同效应,可高效提高聚丙烯腈纤维的阻燃性能。(The invention provides flame-retardant polyacrylonitrile fiber and a preparation method thereof. The raw materials required by the flame-retardant polyacrylonitrile fiber are low in toxicity or non-toxic, the process is simple, the pollution is low, and the flame-retardant polyacrylonitrile fiber is suitable for large-scale development and utilization and is a real environment-friendly green high polymer material; the flame retardant provided by the invention has a phosphorus-nitrogen synergistic effect, and can efficiently improve the flame retardant property of the polyacrylonitrile fiber.)
1. A flame-retardant polyacrylonitrile fiber, which comprises polyacrylonitrile fiber and a flame retardant, wherein the flame retardant is hypophosphite and melamine cyanurate.
2. Flame-retardant polyacrylonitrile fiber according to claim 1, characterized in that the mass ratio of hypophosphite and melamine cyanurate is 70:30-98:2, preferably 70:30-90: 10.
3. The flame-retardant polyacrylonitrile fiber according to claim 1 or 2, wherein the structural formula of the hypophosphite is shown as the formula (I):
in the formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C10Alkoxy radical, C1-C10Alkyl or C6-C20Aryl, preferably selected from hydrogen, C1-C6Alkyl or C6-C10Aryl, more preferably selected from hydrogen, methyl, ethyl or phenyl; m is selected from metal elements, preferably from aluminium, zinc or calcium.
4. Flame-retardant polyacrylonitrile fibers according to any one of claims 1 to 3, characterized in that the mass of the flame retardant is 15-30 wt%, preferably 15-23 wt%, of the mass of the polyacrylonitrile fibers.
5. A preparation method of flame-retardant polyacrylonitrile fibers comprises the following steps:
step S1: contacting polyacrylonitrile fibers with an organic solvent to obtain a first mixture;
step S2: mixing the first mixture with a flame retardant to obtain a second mixture;
step S3: and molding the second mixture to obtain the flame-retardant polyacrylonitrile fiber.
6. The method according to claim 5, wherein the organic solvent is one or more selected from the group consisting of N, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide, and an aqueous solution of sodium thiocyanate; preferably, the mass content of sodium thiocyanate in the sodium thiocyanate aqueous solution is 45-56 wt%; and/or
The flame retardant is hypophosphite and melamine cyanurate, preferably, the mass ratio of the hypophosphite to the melamine cyanurate is 70:30-98:2, preferably 70:30-90: 10.
7. The method according to claim 5 or 6, wherein the hypophosphite has the formula (I):
in the formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C10Alkoxy radical, C1-C10Alkyl or C6-C20Aryl, preferably selected from hydrogen, C1-C6Alkyl or C6-C10Aryl, more preferably selected from hydrogen, methyl, ethyl or phenyl; m is selected from metal elements, preferably from aluminium, zinc or calcium.
8. A method for preparing according to any one of claims 5 to 7, characterized in that the polyacrylonitrile fibers constitute 10 to 30 wt.%, preferably 11 to 25 wt.%, of the first mixture; and/or the addition amount of the flame retardant is 15-30 wt% of the addition amount of the polyacrylonitrile fiber, and preferably 15-23 wt%.
9. The production method according to any one of claims 5 to 8,
in step S1, the contact temperature is 60-100 ℃; and/or
In step S2, the mixing temperature is 60-100 ℃; and/or
In step S3, the forming process includes forming, drawing, water washing, and oiling.
10. Use of the flame retardant polyacrylonitrile fiber according to any one of claims 1 to 4 or the flame retardant polyacrylonitrile fiber obtained by the preparation method according to any one of claims 5 to 9 in the field of functional textiles.
Technical Field
The invention relates to a flame-retardant polyacrylonitrile fiber and a preparation method thereof.
Background
The polyacrylonitrile fiber, also called acrylic fiber, is prepared by copolymerizing acrylonitrile with a mass fraction of more than 85% and a second monomer and a third monomer and then carrying out dry spinning or wet spinning. Acrylic is also known as synthetic wool because of its good bulkiness and elasticity.
Textiles have been widely used in various industries as daily necessities closely related to human life, but because textiles are flammable, the possibility of fire hazard caused by the textiles in the using process is continuously increased, and the safety of life and property of people is greatly threatened. Particularly, the limit oxygen index (17-20%) of the acrylic fiber is low, the fiber and the product thereof are easy to burn and even cause fire, according to the survey data of European fire retardant society, 5000 people in Europe can be killed by the fire caused by textile burning every year, therefore, the flame retardant development of the acrylic fiber has great practical significance.
In the prior art, three ways are generally adopted for flame-retardant modification of polyacrylonitrile fibers, one way is impregnation by using a flame retardant, and the method is generally called as a fabric after-finishing method, has great environmental pollution and is generally not washable; the other is that the copolymerization or blending of the fire retardant containing halogen element, such as acrylonitrile-chloro-acrylic fiber spun by copolymerization of acrylonitrile with vinyl chloride or vinylidene chloride, is the only industrialized copolymerization fire-retardant polyacrylonitrile fiber in the world, and has good fire-retardant performance, but the fiber and the product thereof can emit a large amount of smoke during combustion and also have toxic hydrogen halide gas, so that the popularization and the use of the acrylonitrile-chloro-acrylic fiber are greatly hindered, and especially the development of the environment-friendly fire-retardant polyacrylonitrile fiber is very important at the present of advocating environment protection; thirdly, the use of phosphorus-containing flame retardants is limited by the fact that the flame retardants are expensive or the preparation process is toxic and harmful, and no commercial product is yet available.
Disclosure of Invention
Aiming at the problems in the prior art, the invention provides the flame-retardant polyacrylonitrile fiber and the preparation method thereof, the polyacrylonitrile fiber (acrylic fiber) which is blended and modified by the flame retardant containing phosphorus and the melamine cyanurate has the characteristic of flame-retardant modification, the flame-retardant structure introduced by the invention does not contain halogen elements of the traditional flame retardance, and the required raw materials are low-toxic or nontoxic, so that the flame-retardant polyacrylonitrile fiber has no toxicity problem of the halogen elements and no environmental pollution problem in the combustion process, has simple process and low pollution, is suitable for large-scale development and utilization, and is a real environment-friendly green high polymer material; the flame retardant provided by the invention has a phosphorus-nitrogen synergistic effect, and can efficiently improve the flame retardant property of the polyacrylonitrile fiber.
The invention provides a flame-retardant polyacrylonitrile fiber in a first aspect, which comprises a polyacrylonitrile fiber and a combustion improver, wherein the combustion improver is hypophosphite and melamine cyanurate.
According to some embodiments of the invention, the ratio by mass of hypophosphite and melamine cyanurate is 70:30 to 98:2, such as 72:28, 74:26, 78:22, 80:20, 82:18, 84:16, 86:14, 88:12, 90:10, 92:8, 94:6, 96: 4.
According to a preferred embodiment of the invention, the mass ratio between hypophosphite and melamine cyanurate is between 70:30 and 90: 10.
According to some embodiments of the invention, the hypophosphite salt has the structural formula shown in formula (I):
in the formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C10Alkoxy radical, C1-C10Alkyl or C6-C20An aryl group; m is selected from metal elements.
According to a preferred embodiment of the invention, in formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C6Alkyl or C6-C10And (4) an aryl group.
According to a further preferred embodiment of the invention, in the formula (I), R1And R2Are the same or different and are each independently selected from hydrogen,Methyl, ethyl or phenyl.
According to a preferred embodiment of the invention, in formula (I), M is selected from aluminium, zinc or calcium.
According to some embodiments of the invention, the mass of the flame retardant is 15 to 30 wt% of the mass of the polyacrylonitrile fibers.
According to a preferred embodiment of the invention, the mass of the flame retardant is 15 to 23 wt% of the mass of the polyacrylonitrile fibers.
The second aspect of the invention provides a preparation method of flame-retardant polyacrylonitrile fibers, which comprises the following steps:
step S1: contacting polyacrylonitrile fibers with an organic solvent to obtain a first mixture;
step S2: mixing the first mixture with a flame retardant to obtain a second mixture;
step S3: and molding the second mixture to obtain the flame-retardant polyacrylonitrile fiber.
According to some embodiments of the invention, the flame retardant is hypophosphite or melamine cyanurate.
According to some embodiments of the invention, the ratio by mass of hypophosphite and melamine cyanurate is 70:30 to 98:2, such as 72:28, 74:26, 78:22, 80:20, 82:18, 84:16, 86:14, 88:12, 90:10, 92:8, 94:6, 96: 4.
According to a preferred embodiment of the invention, the mass ratio between hypophosphite and melamine cyanurate is between 70:30 and 90: 10.
According to some embodiments of the invention, the organic solvent is selected from one or more of N, N-dimethylformamide, N-dimethylacetamide, dimethylsulfoxide, and aqueous sodium thiocyanate.
According to a preferred embodiment of the present invention, the sodium thiocyanate solution contains 45 to 56 wt% of sodium thiocyanate.
According to some embodiments of the invention, the hypophosphite salt has the structural formula shown in formula (I):
in the formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C10Alkoxy radical, C1-C10Alkyl or C6-C20An aryl group; m is selected from metal elements.
According to a preferred embodiment of the invention, in formula (I), R1And R2The same or different, each independently selected from hydrogen and C1-C6Alkyl or C6-C10And (4) an aryl group.
According to a further preferred embodiment of the invention, in the formula (I), R1And R2Identical or different, each independently selected from hydrogen, methyl, ethyl or phenyl.
According to a preferred embodiment of the invention, in formula (I), M is selected from aluminium, zinc or calcium.
According to some embodiments of the invention, the polyacrylonitrile fibers constitute 10 to 30 wt% of the first mixture. According to some embodiments of the invention, the polyacrylonitrile fibers constitute 10 to 30 wt% of the first mixture. The inventor of the present invention found that a polyacrylonitrile fiber having excellent flame retardancy can be obtained only by controlling the mass ratio of the polyacrylonitrile fiber to the first mixture within a suitable range; if the mass ratio of the polyacrylonitrile fiber to the first mixture is too low, for example, 5%, the spinning solution cannot be spun; too high, e.g. 40%, the dope cannot be spun, and the spinning equipment becomes clogged.
According to a preferred embodiment of the invention, the polyacrylonitrile fibers represent 11 to 25 wt% of the first mixture.
According to some embodiments of the invention, the flame retardant is added in an amount of 15 to 30 wt% of the polyacrylonitrile fibers.
According to a preferred embodiment of the present invention, the flame retardant is added in an amount of 15 to 23 wt% of the polyacrylonitrile fiber.
According to some embodiments of the invention, the contacting temperature is 60-100 ℃ in step S1.
According to some embodiments of the invention, in step S1, the contacting time is 0.5 to 2 hours.
According to some embodiments of the invention, the temperature of the mixing is 60-100 ℃ in step S2.
According to some embodiments of the invention, the mixing time is 10-60min in step S2.
According to some embodiments of the invention, the forming process in step S3 includes solidifying, forming, drawing, water washing and oiling.
According to some specific embodiments of the present invention, the preparation method of the flame-retardant polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving general acrylic fiber (polyacrylonitrile) powder with a solvent, and uniformly stirring at 60-100 ℃;
(2) directly adding a flame retardant into the solution obtained in the step (1) and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning solution to a spinning device, extruding the spinning solution through a spinning nozzle, forming in a coagulating bath, and performing drafting, washing and oiling processes to obtain the flame-retardant polyacrylonitrile fiber.
The third aspect of the invention provides an application of the flame-retardant polyacrylonitrile fiber according to the first aspect or the flame-retardant polyacrylonitrile fiber obtained by the preparation method according to the second aspect in the field of functional textiles.
The invention has the following advantages:
1. different from common polyester, polyolefin and other high polymer products, phosphate groups generated when hypophosphite is decomposed by heating can catalyze polyacrylonitrile chain segments to form carbon, so that the solid-phase flame retardant effect is achieved.
2. The polyacrylonitrile fiber (acrylic fiber) adopts the traditional wet spinning process and the blending system of hypophosphite and melamine cyanurate in the processing process, has simple process, less emigration and good compatibility, and avoids the introduction of a large amount of flame retardant to reduce the mechanical property, spinnability and other conditions of the polyacrylonitrile material.
Detailed Description
The present invention will be further illustrated by the following examples, but is not limited to these examples.
[ example 1 ]
The preparation method of the flame-retardant polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.2kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the flame retardant polyacrylonitrile fiber was measured to be 33%.
[ example 2 ]
The preparation method of the flame-retardant polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.15kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 28%.
[ example 3 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 35%.
[ example 4 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate in a mass ratio of 90:10 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 34%.
[ example 5 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate in a mass ratio of 70:30 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 33.5%.
[ example 6 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate in a mass ratio of 98:2 to obtain a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 32%.
[ example 7 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 60:40 to prepare a compound flame retardant modifier, directly adding 0.2kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 28.5%.
[ example 8 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate in a mass ratio of 40:60 to obtain a compound flame retardant modifier, directly adding 0.2kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 27%.
[ example 9 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) 1kg of general acrylic fiber powder is mixed and dissolved with 3kg of sodium thiocyanate aqueous solution, wherein the mass content of the sodium thiocyanate is 45 wt%, and the mixture is stirred for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 34%.
[ example 10 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of general acrylic fiber powder and 3kg of N, N-dimethylformamide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 34.5%.
[ example 11 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of general acrylic fiber powder and 3kg of N, N-dimethylacetamide, and stirring at 85 ℃ for 30 min;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 34.5%.
[ example 12 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 0.6kg of general acrylic fiber powder and 3.4kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.2kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 33%.
[ example 13 ]
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 0.8kg of general acrylic fiber powder and 3.2kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.2kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 32.5%.
Comparative example 1
The preparation of the acrylic fiber in the comparative example is completed according to the prior art process, namely the process is the same as that of the example 1, and the difference is only the step of not adding the compound flame retardant. The LOI value of the obtained acrylic fiber is 18 percent.
Comparative example 2
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) directly adding 0.2kg of aluminum hypophosphite flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 26.5%.
Comparative example 3
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) directly adding 0.2kg of melamine cyanurate fire retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 22%.
Comparative example 4
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing trimethyl phosphate and melamine cyanurate with the mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 23.5%.
Comparative example 5
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and urea in a mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), and uniformly stirring for 30min to obtain spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 27.5%.
Comparative example 6
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and ammonium polyphosphate in a mass ratio of 80:20 to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 27%.
Comparative example 7
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) uniformly mixing aluminum hypophosphite and pentaerythritol diphosphate melamine salt in a mass ratio of 80:20 to obtain a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 30%.
Comparative example 8
The preparation method of the polyacrylonitrile fiber comprises the following steps:
(1) mixing and dissolving 1kg of universal acrylic fiber powder and 3kg of dimethyl sulfoxide, and stirring for 30min at 85 ℃;
(2) taking pentaerythritol diphosphate melamine salt in a mass ratio of 16:16:52: 16: melamine cyanurate: aluminum hypophosphite: uniformly mixing triphenyl phosphate to prepare a compound flame retardant modifier, directly adding 0.23kg of the prepared compound flame retardant into the solution obtained in the step (1), stirring for 30min, and uniformly mixing to obtain a spinning stock solution;
(3) and (3) conveying the obtained spinning stock solution into spinning equipment, extruding the spinning stock solution by a spray head, forming the spinning stock solution in a coagulating bath, and then preparing the flame-retardant fiber by the processes of coagulating bath drafting, washing and oiling, wherein the spinning conditions are controlled in such a way that the pump supply is 1.2g/min and the spray head is 30 holes. The LOI of the polyacrylonitrile fiber was measured to be 33.5%.
Obviously, compared with the comparative example, the phosphorus-nitrogen element-containing flame-retardant polyacrylonitrile fiber prepared by the method has excellent flame-retardant performance and great technical advantages, and can be applied to the production of environment-friendly flame-retardant polyacrylonitrile fiber.
It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.