CN112760736A - Flame-retardant polyamide fiber and preparation method thereof - Google Patents
Flame-retardant polyamide fiber and preparation method thereof Download PDFInfo
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- CN112760736A CN112760736A CN202110077263.2A CN202110077263A CN112760736A CN 112760736 A CN112760736 A CN 112760736A CN 202110077263 A CN202110077263 A CN 202110077263A CN 112760736 A CN112760736 A CN 112760736A
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- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
- D01F6/60—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from polyamides
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
- C08G69/48—Polymers modified by chemical after-treatment
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Abstract
The invention discloses a flame-retardant polyamide fiber, which is prepared by the steps of reacting chlorinated paraffin with p-hydroxybenzoic acid to prepare chlorinated paraffin containing carboxyl, acylating the chlorinated paraffin containing carboxyl, carrying out esterification reaction on the acylated chlorinated paraffin and 5-hydroxyisophthalic acid to prepare binary acid modified by the chlorinated paraffin, then reacting the acylated chlorinated paraffin with 4,4' -diaminodiphenyl sulfone to prepare polyamide modified by the chlorinated paraffin, and finally carrying out wet spinning to obtain the polyamide fiber modified by the chlorinated paraffin.
Description
Technical Field
The invention relates to a flame-retardant polyamide fiber and a preparation method thereof, belonging to the field of organic fiber materials.
Background
The aromatic polyamide fiber is an organic high-performance high polymer material with excellent performance, is called aramid fiber for short, has the characteristics of high strength, high modulus, light specific gravity, high temperature resistance and the like, and is one of strategic materials for solving the key problems in the scientific and technological fields of energy, transportation, national defense and the like faced by human beings. In some extreme working environments, such as high temperature, electric welding, steel works, etc., in order to protect the personal safety of operators, polyamide fibers with good flame-retardant and heat-resistant properties are required.
The chlorinated paraffin is a chlorinated derivative of paraffin, has the advantages of low volatility, flame retardance, good barrier property, low price and the like, can be used as additives such as a plasticizer, a flame retardant and the like, and is already used in a large amount in a flame retardant material, but the addition amount of an additive type flame retardant is relatively large, and the flame retardant property is general. As the service time is prolonged, the additive flame retardant is easy to migrate out of the polymer network, and the durability of flame retardance is reduced.
Disclosure of Invention
Aiming at the defects of the chlorinated paraffin in the application of the flame-retardant polyamide fiber in the prior art, the invention aims to provide the polyamide fiber with the molecular side chain containing the chlorinated paraffin molecule.
The invention also aims to provide a method for preparing the flame-retardant polyamide fiber, which has the advantages of wide raw material source, simple operation and mild reaction conditions.
The invention discloses a flame-retardant polyamide fiber, which is characterized by having a structure shown in a formula (I):
in the formula (I), R is a chlorinated paraffin chain segment.
The invention also provides a preparation method of the flame-retardant polyamide, which comprises the following steps:
step (1): preparation of chlorinated paraffins containing carboxyl groups
Dissolving chlorinated paraffin in butanone, adding a certain amount of p-hydroxybenzoic acid and potassium carbonate, and heating to react under the protection of nitrogen to obtain chlorinated paraffin containing carboxyl;
step (2): preparation of chlorinated paraffins containing acid chlorides
Carrying out phosphorus trichloride acylation on the chlorinated paraffin containing carboxyl obtained in the step (1) to obtain chlorinated paraffin containing acyl chloride;
and (3): preparation of modified chlorinated Paraffin dibasic acid
Slowly dripping the chlorinated paraffin containing acyl chloride prepared in the step (2) into a mixed system of 5-hydroxyisophthalic acid and acid-binding agent triethylamine under the protection of nitrogen to perform esterification reaction to obtain modified chlorinated paraffin dibasic acid;
and (4): preparation of modified chlorinated Paraffin Dichloride
Carrying out phosphorus trichloride acylation on the modified chlorinated paraffin diacid obtained in the step (3) to obtain modified chlorinated paraffin diacid chloride;
and (5): preparation of chlorinated Paraffin-modified Polyamide
And (3) under the protection of nitrogen, adding 4,4' -diamino diphenyl sulfone into the mixed solvent, stirring and dissolving at room temperature, then cooling the reaction kettle to 0 ℃, adding the modified chlorinated paraffin diacid chloride obtained in the step (4), and stirring and reacting to obtain the chlorinated paraffin modified polyamide.
The preparation method of the chlorinated paraffin-modified polyamide of the invention also comprises the following preferred scheme:
preferably, the chlorinated paraffin containing carboxyl is prepared by reacting the chlorinated paraffin with p-hydroxybenzoic acid in the step (1) at the temperature of 55-80 ℃ for 10-30 h.
Preferably, the chlorinated paraffin containing carboxyl in the step (2) reacts with excessive phosphorus trichloride at the temperature of 50-70 ℃ for 4-6 h to prepare chlorinated paraffin containing acyl chloride.
More preferably, the molar ratio of the reaction between the chlorinated paraffin containing acyl chloride and the 5-hydroxyisophthalic acid in the step (3) is 1-1.2: 1.
Preferably, the esterification reaction in the step (3) is carried out under the reaction condition that chlorinated paraffin containing acyl chloride is slowly dripped into the mixed solution of 5-hydroxyisophthalic acid and an acid binding agent at the temperature of 15-25 ℃ for reaction, and the reaction is continued for 3-5 hours after the dripping is finished.
Preferably, the modified chlorinated paraffin diacid reacts with excessive phosphorus trichloride for 4-6 hours at the temperature of 50-70 ℃ in the step (4) to prepare the modified chlorinated paraffin diacid chloride.
Further preferably, the molar ratio of the modified chlorinated paraffin diacid chloride reacted with the 4,4' -diaminodiphenyl sulfone in the step (5) is 1.01: 1.
More preferably, the mixed solvent in the step (5) is an anhydrous N-methyl-2-pyrrolidone solution containing 6 mass% of calcium chloride.
Preferably, in the step (5), the modified chlorinated paraffin diacid chloride and the 4,4' -diamino diphenyl sulfone firstly react for 1 to 2 hours at the temperature of 0 ℃, then the temperature is raised to 60 to 80 ℃, and the reaction is continued for 3 to 5 hours.
The invention has the beneficial effects that: according to the invention, traditional chlorinated paraffin molecules are introduced into polyamide molecular chains through chemical bonds for the first time to form a novel polyamide fiber, as the molecular side chains contain a large amount of chlorinated paraffin molecules, the arrangement regularity of the polymer macromolecular chains can be reduced, the solubility and the flame retardance of the fiber are effectively improved, and the molecular main chain contains rigid benzene rings and polar sulfone groups, so that the polyamide fiber is endowed with excellent flame retardance, heat resistance and good mechanical properties. The whole preparation process has the advantages of easily available raw materials, low cost, simple operation, high purity of the obtained product and high yield, and meets the requirements of industrial production.
Drawings
FIG. 1 is an infrared image of a chlorinated paraffin-modified polyamide obtained in example 1.
FIG. 1: 3300cm-1Is the absorption peak of N-H stretching vibration, 3030cm-1Is a C-H stretching vibration absorption peak on a benzene ring, and is 2920cm-1And 2860cm-1Is the absorption peak of stretching vibration of methyl and methylene, 1470cm-1And 1370cm-11750cm as bending vibration absorption peak of methyl-1Is the stretching vibration absorption peak of C ═ O in the ester group, 1660cm-1Absorption peak of carbonyl group in amide, 1520cm-1Is a bending vibration absorption peak of N-H and a stretching vibration absorption peak of C-N in amide, 1480cm-Is a characteristic absorption peak of a benzene ring, 1235cm-1And 1055cm-1Is a characteristic absorption peak of the C-O-C ether bond of 1130cm-1Is a symmetric stretching vibration peak of O-S-O, 510cm-1Here is the stretching vibration peak of the C-Cl bond.
Detailed Description
The following examples are intended to further illustrate the content of the invention, but not to limit the scope of the invention.
Example 1
(1) Preparation of chlorinated paraffin 42 containing carboxyl group: 20g of chlorinated paraffin 42 is dissolved in 210mL of acetone, stirred and dissolved, and then 20g of p-hydroxybenzoic acid and 28g of potassium carbonate are added to react for 30h at 55 ℃ under the protection of nitrogen. After the reaction is finished, hydrochloric acid is used for adjusting the pH value to 3.0, then ethanol is used for extraction, and the product is dried in vacuum at 100 ℃ for 5 hours to obtain chlorinated paraffin 42 containing carboxyl.
(2) Preparation of acid chloride-containing chlorinated paraffin 42: adding 70mol of chlorinated paraffin 42 containing carboxyl into a reaction kettle, dropwise adding 85mol of phosphorus trichloride, stirring, heating to 70 ℃, reacting for 4 hours, cooling to room temperature, standing and layering to obtain chlorinated paraffin 42 containing acyl chloride.
(3) Preparation of chlorinated paraffin 42 modified dibasic acid: adding 5-hydroxyisophthalic acid 100mol and an appropriate amount of acid-binding agent anhydrous triethylamine into a reaction kettle, introducing nitrogen into the reaction kettle, dropwise adding a dichloromethane solution containing chlorinated paraffin 42 containing acyl chloride 101mol at 15 ℃, continuing to react for 5h after dropwise adding, and washing and drying a reaction product to obtain the chlorinated paraffin 42 modified dibasic acid.
(4) Preparation of chlorinated paraffin 42 modified diacid chloride: adding 70mol of chlorinated paraffin 42 modified dibasic acid into a reaction kettle, dropwise adding 100mol of phosphorus trichloride, stirring and heating to 50 ℃, reacting for 6 hours, cooling to room temperature, standing and layering to obtain chlorinated paraffin 42 modified diacid chloride.
(5) Preparation of chlorinated paraffin 42 modified polyamide: adding 50g of anhydrous N-methyl-2-pyrrolidone solution containing 6 mass percent of calcium chloride into a reaction kettle, then adding 50mol of 4,4' -diamino diphenyl sulfone into the mixed solvent, introducing nitrogen into the reaction kettle, stirring for dissolving, adding 50.5mol of chlorinated paraffin 42 modified diacid chloride at the temperature of 0 ℃, stirring for reacting for 1h, then heating the reaction kettle to 60 ℃, and continuing to react for 5h to obtain chlorinated paraffin 42 modified polyamide P1.
Example 2
(1) Preparation of chlorinated paraffin 52 containing carboxyl group: 20g of chlorinated paraffin 52 is dissolved in 220mL of acetone, stirred and dissolved, and then 20g of p-hydroxybenzoic acid and 29g of potassium carbonate are added to react for 10 hours at 80 ℃ under the protection of nitrogen. After the reaction is finished, hydrochloric acid is used for adjusting the pH value to 3.0, then ethanol is used for extraction, and the product is dried in vacuum at 100 ℃ for 5 hours to obtain chlorinated paraffin 52 containing carboxyl.
(2) Preparation of chlorinated paraffin 52 containing acid chloride: adding 70mol of carboxyl-containing chlorinated paraffin 52 into a reaction kettle, dropwise adding 85mol of phosphorus trichloride, stirring, heating to 50 ℃, reacting for 6 hours, cooling to room temperature, standing and layering to obtain the chlorinated paraffin 52 containing acyl chloride.
(3) Preparation of chlorinated paraffin 52 modified dibasic acid: adding 5-hydroxyisophthalic acid 100mol and an appropriate amount of acid-binding agent anhydrous triethylamine into a reaction kettle, introducing nitrogen into the reaction kettle, dropwise adding dichloromethane solution containing chlorinated paraffin 52 containing acyl chloride 103mol at 25 ℃, continuing to react for 3h after dropwise adding, and washing and drying the reaction product to obtain the chlorinated paraffin 52 modified dibasic acid.
(4) Preparation of chlorinated paraffin 52 modified diacid chloride: adding 70mol of chlorinated paraffin 52 modified dibasic acid into a reaction kettle, dropwise adding 100mol of phosphorus trichloride, stirring and heating to 70 ℃, reacting for 4 hours, cooling to room temperature, standing and layering to obtain chlorinated paraffin 52 modified diacid chloride.
(5) Preparation of chlorinated paraffin 52 modified polyamide: adding 50g of anhydrous N-methyl-2-pyrrolidone solution containing 6 mass percent of calcium chloride into a reaction kettle, then adding 50mol of 4,4' -diamino diphenyl sulfone into the mixed solvent, introducing nitrogen into the reaction kettle, stirring for dissolving, adding 50.5mol of chlorinated paraffin 52 modified diacid chloride at the temperature of 0 ℃, stirring for reacting for 2 hours, then heating the reaction kettle to 80 ℃, and continuing to react for 3 hours to obtain the chlorinated paraffin 52 modified polyamide P2.
Example 3
(1) Preparation of carboxyl group-containing chlorinated paraffin 70: dissolving 20g of chlorinated paraffin 70 in 200mL of acetone, stirring to dissolve, adding 20g of p-hydroxybenzoic acid and 30g of potassium carbonate, and reacting at 65 ℃ for 24h under the protection of nitrogen. After the reaction is finished, hydrochloric acid is used for adjusting the pH value to 3.0, then ethanol is used for extraction, and the product is dried in vacuum at 100 ℃ for 5 hours to obtain chlorinated paraffin 70 containing carboxyl.
(2) Preparation of acid chloride-containing chlorinated paraffin 70: adding 70mol of carboxyl-containing chlorinated paraffin 70 into a reaction kettle, dropwise adding 85mol of phosphorus trichloride, stirring, heating to 60 ℃, reacting for 5 hours, cooling to room temperature, standing and layering to obtain the chlorinated paraffin 70 containing acyl chloride.
(3) Preparation of chlorinated paraffin 70 modified dibasic acid: adding 5-hydroxyisophthalic acid 100mol and an appropriate amount of acid-binding agent anhydrous triethylamine into a reaction kettle, introducing nitrogen into the reaction kettle, dropwise adding a dichloromethane solution containing chlorinated paraffin 70 containing acyl chloride 102mol at 20 ℃, continuing to react for 4h after dropwise adding, and washing and drying a reaction product to obtain the chlorinated paraffin 70 modified dibasic acid.
(4) Preparation of chlorinated paraffin 70 modified diacid chloride: adding 70mol of chlorinated paraffin 70 modified dibasic acid into a reaction kettle, dropwise adding 100mol of phosphorus trichloride, stirring and heating to 70 ℃, reacting for 4 hours, cooling to room temperature, standing and layering to obtain chlorinated paraffin 52 modified diacid chloride.
(5) Preparation of chlorinated paraffin 70 modified polyamide: adding 50g of anhydrous N-methyl-2-pyrrolidone solution containing 6 mass percent of calcium chloride into a reaction kettle, then adding 50mol of 4,4' -diamino diphenyl sulfone into the mixed solvent, introducing nitrogen into the reaction kettle, stirring for dissolving, adding 50.5mol of chlorinated paraffin 70 modified diacid chloride at the temperature of 0 ℃, stirring for reacting for 2 hours, then heating the reaction kettle to 70 ℃, and continuing to react for 4 hours to obtain chlorinated paraffin 70 modified polyamide P3.
Comparative example 1
Preparation of polyisophthaloyl diphenyl sulfone diamine: adding 50g of anhydrous N-methyl-2-pyrrolidone solution containing 6 mass percent of calcium chloride into a reaction kettle, then adding 50mol of 4,4' -diamino diphenyl sulfone into the mixed solvent, introducing nitrogen into the reaction kettle, stirring for dissolving, adding 50.5mol of isophthaloyl dichloride at 0 ℃, stirring for reacting for 2 hours, then heating the reaction kettle to 70 ℃, and continuing to react for 4 hours to obtain the poly (m-phthaloyl diphenyl sulfone) diamine P4.
Comparative example 2
Preparation of flame-retardant poly (m-phenylene terephthamide): and adding 100 parts by mass of P4 into a reaction kettle, heating, stirring and dissolving, then adding 15 parts by mass of chlorinated paraffin 42, and uniformly mixing to obtain the flame-retardant poly (m-phenylenethylsulfonyl) diamine P5.
Comparative example 3
Preparation of flame-retardant poly (m-phenylene terephthamide): and adding 100 parts by mass of P4 into a reaction kettle, heating, stirring and dissolving, then adding 15 parts by mass of chlorinated paraffin 42, and uniformly mixing to obtain the flame-retardant poly (m-phenylenethylsulfonyl) diamine P6.
Preparation of Polyamide fibers
Transferring the prepared polyamide into a defoaming kettle, defoaming and filtering at normal pressure, then carrying out wet spinning, spraying the polyamide into a coagulating bath through a spinning nozzle for coagulation and molding to obtain nascent fiber, and then carrying out washing, oiling, drying and heat treatment to obtain the polyamide fiber. The mechanical properties and flame retardant and heat resistance of the polyamide fibers were tested according to national standards, and the test results are shown in table 1.
TABLE 1 Polyamide fiber Performance test results
In conclusion, the traditional chlorinated paraffin molecules are introduced into the polyamide molecular chain through chemical bonds, and the molecular side chain contains a large amount of chlorinated paraffin molecules, so that the arrangement regularity of the polymer macromolecular chain can be reduced, the solubility and the flame retardance of the fiber are effectively improved, and the main chain of the molecule contains a rigid benzene ring and a polar sulfone group, so that the fiber is endowed with excellent flame retardance, heat resistance and good mechanical properties.
Claims (10)
1. A flame retardant polyamide fiber, characterized in that the flame retardant polyamide fiber has a structure represented by formula (I):
in the formula (I), R is a chlorinated paraffin chain segment.
2. The preparation method of the flame-retardant polyamide fiber is characterized by comprising the following steps of:
step (1): preparation of chlorinated paraffins containing carboxyl groups
Dissolving chlorinated paraffin in butanone, adding a certain amount of p-hydroxybenzoic acid and potassium carbonate, and heating to react under the protection of nitrogen to obtain chlorinated paraffin containing carboxyl;
step (2): preparation of chlorinated paraffins containing acid chlorides
Carrying out phosphorus trichloride acylation on the chlorinated paraffin containing carboxyl obtained in the step (1) to obtain chlorinated paraffin containing acyl chloride;
and (3): preparation of modified chlorinated Paraffin dibasic acid
Slowly dripping the chlorinated paraffin containing acyl chloride prepared in the step (2) into a mixed system of 5-hydroxyisophthalic acid and acid-binding agent triethylamine under the protection of nitrogen to perform esterification reaction to obtain modified chlorinated paraffin dibasic acid;
and (4): preparation of modified chlorinated Paraffin Dichloride
Carrying out phosphorus trichloride acylation on the modified chlorinated paraffin diacid obtained in the step (3) to obtain modified chlorinated paraffin diacid chloride;
and (5): preparation of chlorinated Paraffin-modified Polyamide
And (3) under the protection of nitrogen, adding 4,4' -diamino diphenyl sulfone into the mixed solvent, stirring and dissolving at room temperature, then cooling the reaction kettle to 0 ℃, adding the modified chlorinated paraffin diacid chloride obtained in the step (4), and stirring and reacting to obtain the chlorinated paraffin modified polyamide.
3. The method according to claim 2, wherein the chlorinated paraffin containing a carboxyl group is prepared by reacting the chlorinated paraffin with p-hydroxybenzoic acid in the step (1) at a temperature of 55-80 ℃ for 10-30 hours.
4. The preparation method according to claim 2, wherein the chlorinated paraffin containing carboxyl groups in the step (2) is reacted with excess phosphorus trichloride at a temperature of 50-70 ℃ for 4-6 h to prepare chlorinated paraffin containing acyl chloride.
5. The method according to claim 2, wherein the mole ratio of the acid chloride-containing chlorinated paraffin to the 5-hydroxyisophthalic acid in the step (3) is 1 to 1.2: 1.
6. The preparation method according to claim 2, wherein the esterification reaction in the step (3) is carried out under the reaction condition that chlorinated paraffin containing acyl chloride is slowly dripped into the mixed solution of 5-hydroxyisophthalic acid and the acid-binding agent at the temperature of 15-25 ℃ for reaction, and the reaction is continued for 3-5 hours after the dripping is finished.
7. The method according to claim 2, wherein the modified chlorinated paraffin diacid in the step (4) reacts with excess phosphorus trichloride at a temperature of 50-70 ℃ for 4-6 h to obtain the modified chlorinated paraffin diacid chloride.
8. The method according to claim 2, wherein the modified chlorinated paraffin diacid chloride is reacted with 4,4' -diaminodiphenyl sulfone in the step (5) in a molar ratio of 1.01: 1.
9. The production method according to claim 2, wherein the mixed solvent in the step (5) is an anhydrous N-methyl-2-pyrrolidone solution containing 6 mass% of calcium chloride.
10. The method according to claim 2, wherein the reaction conditions in the step (5) are that the modified chlorinated paraffin diacid chloride and the 4,4' -diaminodiphenyl sulfone are firstly reacted for 1 to 2 hours at 0 ℃, then the temperature is raised to 60 to 80 ℃, and the reaction is continued for 3 to 5 hours.
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| CN202110077263.2A CN112760736A (en) | 2021-01-20 | 2021-01-20 | Flame-retardant polyamide fiber and preparation method thereof |
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Application publication date: 20210507 |