Organic phosphorus copolymerized flame-retardant polyamide and preparation method thereof
阅读说明：本技术 一种有机磷系共聚阻燃聚酰胺及其制备方法 (Organic phosphorus copolymerized flame-retardant polyamide and preparation method thereof ) 是由 马永梅 陶云峰 吕文涛 方辉 张京楠 陈群跃 张程夕 易丹青 郑鲲 于 2016-10-25 设计创作，主要内容包括：本发明公开一种有机磷系共聚阻燃聚酰胺及其制备方法。本发明制备方法,具体包括以下步骤：(A)将有机磷系阻燃单体与二胺类单体反应,成盐；(B)将二酸和二胺和/或二元酰胺盐、内酰胺、步骤(A)制备的盐、抗氧剂、催化剂、去离子水加入反应釜,氮气气氛下,通过调控反应温度和压强,原位制得所需有机磷系共聚阻燃聚酰胺材料。本发明制备出的有机磷系聚酰胺材料,反应阻燃剂的添加量小,无需添加协效阻燃剂,制备过程中粘度可控,得到的产物力学性能优良、阻燃性能出色。同时,本制备方法还兼具工艺环保简单,成本低廉,操作易学的特点。(The invention discloses an organic phosphorus copolymerized flame-retardant polyamide and a preparation method thereof. The preparation method specifically comprises the following steps: (A) reacting an organic phosphorus flame-retardant monomer with a diamine monomer to form salt; (B) adding diacid, diamine and/or diamine salt, lactam, the salt prepared in the step (A), an antioxidant, a catalyst and deionized water into a reaction kettle, and preparing the required organic phosphorus copolymerized flame-retardant polyamide material in situ by regulating and controlling reaction temperature and pressure under the nitrogen atmosphere. The organic phosphorus polyamide material prepared by the invention has the advantages of small addition amount of the reaction flame retardant, no need of adding a synergistic flame retardant, controllable viscosity in the preparation process, excellent mechanical property of the obtained product and excellent flame retardant property. Meanwhile, the preparation method has the characteristics of simple and environment-friendly process, low cost and easy operation.)
1. An organic phosphorus copolymerized flame-retardant polyamide, which has a general formula shown as the following formula (1):
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10A heteroaryl group; r is preferably H, C1-C3Alkyl radical, C6-C8Aryl radical, C3-C6A heteroaryl group;
R1、R2each independently selected from linear, branched or cyclic C1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10An ester group; r1、R2Each independently preferably being a straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3、R4、R5each independently selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10A heteroaryl group; r3、R4、R5Are each independently preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10An alkylene group; r6Preferably C3-C9An alkylene group;
x represents 2 to 50; y represents 2 to 50; z represents 2 to 50; n represents 5 to 100.
2. The organophosphorus copolymerized flame-retardant polyamide according to claim 1, wherein x represents 2 to 30; y represents 2 to 30; z represents 2 to 30; n represents 50 to 80.
3. The organophosphorus copolymerized flame retardant polyamide according to claim 1 or 2, which is produced by a production method comprising the steps of:
(A) reacting an organic phosphorus flame-retardant monomer or a derivative thereof shown in a formula (2) with a diamine monomer shown in a formula (3);
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10Heteroaryl, R is preferably H, C1-C3Alkyl radical, C6-C8Aryl radical, C3-C6A heteroaryl group;
R1、R2each independently selected from linear, branched or cyclic C1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10Ester group, R1、R2Each independently preferably being a straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3is selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10Heteroaryl radical, R3Preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8Heteroaryl to obtain a compound of formula (4):
(B) reacting a compound of formula (4) with a diacid of formula (5), a diamine of formula (6) and a lactam monomer of formula (8), or with a diamide salt of formula (7) and a lactam monomer of formula (8),
wherein R is4And R5Is selected from C3-C12Linear, branched or cyclic alkylene、C6-C10Arylene radical, C3-C10Heteroaryl radical, R4And R5Preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10Alkylene radical, R6Preferably C3-C9An alkylene group;
obtaining a polyamide of formula (1):
wherein, R, R1、R2、R3、R4、R5、R6X, y and z are as defined above;
wherein, the flame-retardant monomer in the formula (2) in the step (A) and the diamine monomer in the formula (3) react according to the molar ratio of 1: 1-2; the diamine monomer is excessive relative to the organic phosphorus flame-retardant monomer or the derivative thereof, so that the pH value of the prepared salt solution is 7-9;
the step (B) comprises the following steps:
a. adding diacid, diamine or diamine salt, lactam monomer, the reaction product obtained in the step (A), a catalyst, an antioxidant and deionized water into a reaction kettle, vacuumizing, and filling nitrogen for several times to ensure that the pressure in the kettle is 0.1-0.5MPa at the initial stage of reaction;
b. heating the reaction kettle to 200 ℃ and 250 ℃, and maintaining the reaction condition for 30-180min when the pressure is 1.6-2.1 MPa;
c. slowly releasing the pressure to normal pressure at the temperature of 230 ℃ and 280 ℃, then vacuumizing to-0.01 to-0.1 MPa, and copolymerizing for 10-180 min.
d. Finally, filling nitrogen, discharging materials, cooling, granulating, extracting and drying to obtain a final product;
in step a, the addition amount of the polymerized monomer diacid, diamine or diamine salt and lactam is 8 to 30 times, preferably 8 to 12 times, and more preferably 10 to 12 times of the mass of the flame-retardant monomer.
4. The organophosphorus copolymerized flame-retardant polyamide according to claim 3, wherein, in step a, the polymerized monomers are diacid and diamine capable of participating in copolymerization, and the diacid is one or more of adipic acid, sebacic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid or their derivatives and other aliphatic and aromatic dicarboxylic acids; and the diamine compound is selected from hexamethylenediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, and aliphatic C6-C20One or more of an imino diamine, an aromatic diamine, or an alicyclic diamine; the binary amide salt is one or more of hexamethylene adipamide, pentamethylene adipamide, hexamethylene azelamide, hexamethylene sebacamide, octanedioyl diamine salt;
the antioxidant is one or more of p-phenylenediamine, dihydroquinoline and other compounds and derivatives thereof, 2, 6-di-tert-butyl-4-methylphenol, bis (3, 5-di-tert-butyl-4-hydroxyphenyl) thioether and tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester;
the catalyst is one or more of sodium hypophosphite, methyl benzene sulfonic acid and new ferrocene chiral polyamide ligand.
5. Process for the preparation of a flame retardant polyamide according to claim 1 or 2, comprising the steps of:
(A) reacting an organic phosphorus flame-retardant monomer or a derivative thereof shown in a formula (2) with a diamine monomer shown in a formula (3);
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10Heteroaryl, R is preferably H, C1-C3Alkyl radical, C6-C8Aryl radical, C3-C6A heteroaryl group;
R1、R2each independently selected from linear, branched or cyclic C1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10Ester group, R1、R2Each independently preferably being a straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3is selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10Heteroaryl radical, R3Preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8Heteroaryl to obtain a compound of formula (4):
(B) reacting a compound of formula (4) with a diacid of formula (5), a diamine of formula (6) and a lactam monomer of formula (8), or with a diamide salt of formula (7) and a lactam monomer of formula (8),
wherein R is4And R5Is selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10Heteroaryl radical, R4And R5Preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10Alkylene radical, R6Preferably C3-C9An alkylene group;
obtaining a polyamide of formula (1):
wherein, R, R1、R2、R3、R4、R5、R6X, y, z are as defined above,
reacting the flame-retardant monomer of formula (2) with the diamine monomer of formula (3) in a molar ratio of 1:0.5-10, preferably 1: 1-2; the diamine monomer is excessive relative to the organic phosphorus flame-retardant monomer or the derivative thereof, so that the pH value of the prepared salt solution is 7-9.
6. The preparation method according to claim 5, wherein, in the step (A), the reaction temperature is raised from room temperature to 40-70 ℃ within 5-20 min; and/or
The diamine monomer used in the step (A) is hexamethylene diamine, decamethylene diamine, nonane diamine, undecane diamine, dodecane diamine, aliphatic C6-C20One or more of imino diamine, aromatic diamine and alicyclic diamine; and/or
In the step (B), adding diacid, diamine or diamine salt, lactam monomer, the reaction product obtained in the step (A), antioxidant, catalyst and deionized water into a reaction kettle, and regulating and controlling the reaction temperature and pressure in the nitrogen atmosphere to obtain the required organic phosphorus copolymerized flame-retardant polyamide material.
7. The process according to claim 5 or 6, wherein in the step (B), the antioxidant is one or more selected from the group consisting of p-phenylenediamine, dihydroquinoline, and derivatives thereof, 2, 6-di-tert-butyl-4-methylphenol, bis (3, 5-di-tert-butyl-4-hydroxyphenyl) sulfide, and pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ]; and/or
The catalyst is one or more of sodium hypophosphite, methyl benzene sulfonic acid and new ferrocene chiral polyamide ligand.
8. The preparation method according to any one of claims 5 to 7, wherein the step (B) specifically comprises the steps of:
a. adding diacid, diamine or diamine salt, lactam monomer, the reaction product obtained in the step (A), a catalyst, an antioxidant and deionized water into a reaction kettle, vacuumizing, and filling nitrogen for several times to ensure that the pressure in the kettle is 0.1-0.5MPa at the initial stage of reaction;
b. heating the reaction kettle to 200 ℃ and 250 ℃, and maintaining the reaction condition for 30-180min when the pressure is 1.6-2.1 MPa;
c. slowly releasing the pressure to normal pressure at the temperature of 230 ℃ and 280 ℃, then vacuumizing to-0.01 to-0.1 MPa, and copolymerizing for 10-180 min;
d. and finally, filling nitrogen, discharging materials, cooling, granulating, extracting and drying to obtain a final product.
9. The preparation method according to claim 8, wherein in step a, the addition amount of the polymerized monomer diacid and diamine or diamine salt of diamine, lactam is 8-30 times, preferably 8-12 times, more preferably 10-12 times of the mass of the flame retardant monomer, wherein the molar ratio of diacid and diamine and/or diamine salt of diamine to lactam is 1:0.01-100, preferably 1:0.1-10, more preferably 1: 0.5-5; the catalyst and the antioxidant are respectively 0.01 to 1.0 percent of the mass of the polymerized monomer diacid and diamine or diamide salt and lactam, preferably 0.05 to 0.5 percent of the mass of the polymerized monomer diacid and diamine or diamide salt, more preferably 0.08 to 0.2 percent of the mass of the polymerized monomer lactam, and more preferably about 1/1000; the amount of water added is 10-60%, preferably 30-50% of the polymerized monomers; and/or
In the step a, the polymerization monomers are diacid and diamine which can participate in copolymerization, and the diacid is one or more of adipic acid, sebacic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid or derivatives thereof and other aliphatic and aromatic dicarboxylic acids; and the diamine compound is selected from hexamethylenediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, and aliphatic C6-C20One or more of imino diamine, aromatic diamine or alicyclic diamineA plurality of types; the binary amide salt is one or more of hexamethylene adipamide, pentamethylene adipamide, hexamethylene azelainate, hexamethylene sebacamide, octanedioyl octanediamine, octanedioyl hexamethylene diamine and octanedioyl octanediamine.
Technical Field
The invention belongs to the technical field of synthesis of flame-retardant polymers, relates to a preparation method of copolymerized flame-retardant polyamide, and particularly relates to a phosphorus-containing reactive flame retardant copolymerized polymer material embedded in a polyamide molecular chain and a preparation method thereof.
Background
The polyamide has excellent performances such as high strength, heat resistance, wear resistance, solvent resistance and the like, and is widely applied to the fields of buildings, chemical engineering, traffic, military and the like. However, polyamides are not inherently flame retardant and may cause or exacerbate fire hazards. Therefore, the modification of polyamide to obtain polyamide with good flame-retardant properties has been studied by the industry.
There are generally two ways in which the flame retardant polyamide material can be modified: one is adding reactive flame retardant, introducing functional group with flame retardant activity in the nylon copolymerization process; and the other is that after the polyamide is polymerized, an additive flame retardant and a related synergistic flame retardant are added and blended. The latter physical blending mode is influenced by the factors of dispersibility, compatibility, interfacial property and the like, while the former does not have the problems because of chemical reaction. In addition, to achieve a certain flame retardance, the use amount of the additive flame retardant is large, so that the mechanical property and the electrical property are greatly damaged, and the application of the additive flame retardant is limited. The reactive flame retardant can well solve the problems, the molecular structure of the reactive flame retardant is copolymerized into the main chain of the polyamide molecule, the problems of volatilization, migration, exudation and the like do not exist, and the reactive flame retardant can provide reliable flame retardant performance within the service life of the material.
At present, the commonly used flame retardants mainly include halogen flame retardants, phosphorus flame retardants, nitrogen flame retardants, inorganic filler type flame retardants, and the like. Halogen-containing flame retardants have been widely used as flame retardant materials for high polymers due to their high flame retardancy, but they are gradually limited in use because they generate toxic gases and fumes during combustion, which are harmful to the environment and human body. The phosphorus flame retardant, especially the organic phosphorus flame retardant has a prospect of replacing halogen-containing flame retardants. The phosphorus flame retardant can act in a condensed phase and a gas phase at the same time, and the flame retardant mechanism is that the flame retardant can generate products such as phosphoric acid, polyphosphoric acid and the like in the combustion process, so that the dehydration and carbonization of a polymer are promoted, a glassy protective layer is formed, and the heat and substance transfer between the condensed phase and the gas phase is prevented. The combustion process of the phosphorus-containing flame retardant does not generate toxic and harmful gas, has less smoke generation amount and has better flame retardant effect. Particularly, the reactive phosphorus flame retardant can enter the molecular main chain of a high polymer material needing flame retardance in a polymerization mode, does not migrate and exude, and is effective for a long time.
The patent with publication number CN104231262A discloses a preparation method of organophosphorus copolymerized flame-retardant polyamide, which comprises the following steps: (1) reacting a flame-retardant monomer with a diamine monomer in advance to prepare a prepolymer; (2) and adding a polymerization monomer, a catalyst and the prepolymer into the reaction kettle in a certain sequence. The flame retardant used in this patent isOr a derivative of a substrate thereof; wherein said R1And R2Alkylene groups each having 1 to 10 carbon atoms; or R1And R2Any of which is H; x1、X2Is H or 1-4 canHalogen substituted for H on the phenyl ring. The flame retardant grade of the copolymerization product obtained in the invention can reach UL94V-0 grade, the limiting oxygen index is greatly improved, the lowest value can reach 32, and the highest value can reach 45.
The patent with the publication number of CN104262619A relates to phosphorus-containing flame-retardant polyamide and a preparation method and application thereof. The preparation method comprises the following steps: (1) carrying out pre-polycondensation reaction on hypophosphite used for flame retardance and diamine to generate an oligomer; (2) carrying out pre-polycondensation reaction on the oligomer and dicarboxylic acid salt in a nitrogen atmosphere to obtain a prepolymer; (3) after two times of pre-polycondensation reaction, raising the temperature and reducing the air pressure to normal pressure; (4) and raising the temperature, pumping air to vacuum, and discharging to obtain the flame-retardant polyamide material. The flame retardant used in this patent is
Wherein R is1And R2Is straight-chain, branched or cyclic C1-C15Alkylene radical, C6-C15Arylene or aralkylene; m is a metal element, and when a is 1, M is lithium, sodium or potassium; when a is 2, M is calcium or magnesium. In the invention, when the phosphorus content reaches more than 0.48 percent, the flame-retardant polyamide can pass the UL-94V-0 grade, and the LOI value is also obviously improved.
The patent publication No. JPH09328543 relates to a polyamide copolymer containing phosphorus in the main chain and a method for preparing the same. The preparation method comprises the steps of (1) pre-reacting phosphorus-containing dicarboxylate with diamine to form salt; (2) the salt is condensed with other comonomers (diacid and diamine, or caprolactam) to produce polyamide copolymers. In this patent, the dicarboxylate is
Wherein R is1Is straight chain or branched chain alkyl with 1 to 8 carbon atoms; r2Is H or methyl. When the phosphorus content in the prepared polyamide copolymer is 6.48-6.58ppm, the limit oxygen index can reach 28.9-29.9%, and the polyamide copolymer has better flame retardant property. But the relative viscosity of the prepared polyamide material is only 0.78-0.82, and the mechanical property of the material sampleAnd other performances have larger lifting space.
As described above, although the prior art has proposed many phosphorus-containing polyamides with good flame retardant properties, there is still a strong need in the art for flame retardant polyamides with good mechanical, electrical and flame retardant properties.
Disclosure of Invention
The invention aims to prepare a novel organic phosphorus copolymerization flame-retardant polyamide material aiming at the situation that the existing market of flame-retardant polyamide mainly adopts blending. The method is characterized in that the novel organic phosphorus copolymerized flame-retardant polyamide is prepared by salifying a flame-retardant monomer with diamine by utilizing the characteristic that the flame-retardant monomer has two carboxylic acid groups and then carrying out polycondensation with diamine salt of dicarboxylic acid. In the process, the addition amount of the flame retardant is small, no synergistic flame retardant is needed, and the obtained polyamide material has excellent mechanical and electrical properties.
The technical scheme of the invention is as follows:
a flame-retardant polyamide represented by the following general formula (1):
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10A heteroaryl group; r is preferably H, C1-C3Alkyl radical, C6-C8Aryl, or C3-C6A heteroaryl group;
R1、R2each independently selected from linear, branched or cyclic C1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10An ester group; r1、R2Each independently of the others is preferably straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3、R4、R5each independently selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10A heteroaryl group; r3、R4、R5Each independently is preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10An alkylene group; r6Preferably C3-C9An alkylene group;
x represents 1 to 50; y represents 1 to 50, z represents 1 to 50; n represents 1 to 100; x is preferably from 2 to 30, y is preferably from 2 to 30, z is preferably from 2 to 30, and n is preferably from 2 to 80, more preferably from 5 to 50.
The preparation method of the flame-retardant polyamide comprises the following steps:
(A) reacting an organic phosphorus flame-retardant monomer or a derivative thereof shown in a formula (2) with a diamine monomer shown in a formula (3);
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10Heteroaryl, R is preferably H, C1-C3Alkyl radical, C6-C8Aryl radical, C3-C6A heteroaryl group;
R1、R2each independently selected from linear, branched or cyclic C1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10Ester group, R1、R2Each independently preferably being a straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3is selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10Heteroaryl radical, R3Preference is given toIs C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
obtaining a compound of the following formula (4):
(B) reacting a compound of formula (4) with a diacid of formula (5) and a diamine of formula (6) and a lactam monomer of formula (8), or with a diamide salt of formula (7) and a lactam monomer of formula (8),
wherein R is4And R5Is selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10Heteroaryl radical, R4And R5Each is preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10Alkylene radical, R6Preferably C3-C9An alkylene group;
obtaining a polyamide of formula (1):
wherein, R, R1、R2、R3、R4、R5、R6As defined above; x represents 1 to 50, y represents 1 to 50, z represents 1 to 50, and n represents 1 to 100; preferably, x represents 2 to 30, y represents 2 to 30, z represents 2 to 30 and n represents 2 to 80, more preferably 5 to 50.
Preferably, the flame retardant monomer of formula (2) is reacted with the diamine monomer of formula (3) in a molar ratio of 1:0.1 to 20, preferably 1:0.5 to 10, more preferably 1:1 to 2.
In step (A), the diamine-based monomer is preferably in excess (e.g., 0.1 to 10%, preferably 0.5 to 5% molar excess) relative to the organophosphorus flame retardant monomer or derivative thereof, so that the resulting salt solution has a pH of 7 to 9. The reaction temperature is increased from room temperature to 40-70 ℃ within 5-20 min.
Preferably, the diamine monomer used in step (A) is hexamethylenediamine, decamethylenediamine, nonanediamine, undecanediamine, dodecanediamine, aliphatic C6-C20One or more of imino diamine, aromatic diamine and alicyclic diamine.
In the step (B), the molar ratio of the diacid of the formula (5) to the diamine of the formula (6) is not particularly limited, and for example, the molar ratio of the diacid of the formula (5) to the diamine of the formula (6) may be 1:1 to 10, preferably 1:1 to 2, more preferably about 1: 1.5.
In the step (B), preferably, the polymerization monomers (diacid, diamine or diamine salt and lactam), the reaction product (salt or salt solution) of the step (A), the antioxidant, the catalyst and the deionized water are added into a reaction kettle, and the reaction temperature and the reaction pressure are regulated and controlled under the nitrogen atmosphere to prepare the required organic phosphorus copolymerized flame-retardant polyamide.
In the step (B), further, the antioxidant is one or more of compounds such as p-phenylenediamine and dihydroquinoline and derivatives thereof, 2, 6-di-tert-butyl-4-methylphenol, bis (3, 5-di-tert-butyl-4-hydroxyphenyl) sulfide, pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and the like.
Furthermore, the catalyst is one or more of sodium hypophosphite, methyl benzene sulfonic acid, a new ferrocene chiral polyamide ligand and the like.
Further preferably, the step (B) specifically includes the following steps:
a. adding a polymerization monomer, the reaction product obtained in the step (A), a catalyst, an antioxidant and deionized water into a reaction kettle, vacuumizing, and filling nitrogen for several times to ensure that the pressure in the kettle is 0.1-0.5MPa in the initial stage of reaction;
b. heating the reaction kettle to 200 ℃ and 250 ℃, and maintaining the reaction condition for 30-180min when the pressure is 1.6-2.1 MPa;
c. slowly releasing the pressure to normal pressure at the temperature of 230 ℃ and 280 ℃, then vacuumizing to-0.01 to-0.1 MPa, and copolymerizing for 10-180 min.
d. And finally, filling nitrogen, discharging materials, cooling, granulating, extracting and drying to obtain a final product.
Further, in step a, the addition amount of the polymerization monomer (including lactam and diacid and diamine or diamine salt) is 8 to 100 times, preferably 10 to 40 times, more preferably 12 to 30 times of the mass of the flame retardant, wherein the molar ratio of each diacid and diamine or diamine salt to lactam is 1:0.01 to 100, preferably 1:0.1 to 10, more preferably 1:0.5 to 5, and in the case of using diacid and diamine, the molar ratio of the diacid and diamine can be 1:1.01 to 10.0, preferably 1:1.1 to 2.0, more preferably about 1:1.1 to 1.5; the catalyst and the antioxidant are respectively 0.01-1.0 percent of the mass of the polymerization monomer, preferably 0.05-0.5 percent of the mass of the polymerization monomer, more preferably 0.08-0.2 percent of the mass of the polymerization monomer, and more preferably about 1/1000 percent of the mass of the polymerization monomer. The amount of water added to the system (including water added separately, water entrained with the product of step (A), and water entrained with the dibasic amide salt) is 10 to 60%, preferably 30 to 50%, of the total mass of the reactants.
Further, in step a, the polymerized monomer diacid is one or more of adipic acid, sebacic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid or their derivatives and other aliphatic and aromatic dicarboxylic acids; the diamine compound is, for example, hexamethylenediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, and aliphatic C6-C20One or more of an imino diamine, an aromatic diamine, or an alicyclic diamine; the diamine salt is one or more of hexamethylene adipamide, pentamethylene adipamide, hexamethylene azelainate, hexamethylene sebacamide, octanedioyl octanediamine, octanedioyl hexamethylene diamine and octanedioyl octanediamine. The lactam in the polymerization monomer is one or more of caprolactam, decanolactam, undecanolactam, dodecanolactam and various lactam monomers with lactam characteristics.
In the present invention, the flame retardant and the diamine-based monomer are preferably mixed in advance in a ratio of, for example, 1: (1-2) salifying, adding the obtained salt solution into a polymerization monomer, and participating in polymerization reaction under the action of a catalyst. The flame retardant property of the obtained polyamide material meets the requirement of flame retardant grade V-0.
To be provided withHexamethylenediamine, PA66 salt, caprolactam are examples, the mechanism of the reaction is: the flame-retardant monomer reacts with hexamethylene diamine to form salt, and then the salt, nylon 66 salt and caprolactam are copolymerized to form the flame-retardant polyamide. The reaction process can be written as:
the invention has the beneficial effects that:
as long as the flame-retardant polyamide comprises phosphorus-containing flame-retardant monomers accounting for about 6 percent of the mass of the polymer, the flame-retardant polyamide can basically reach UL-94V-0 level, the limit oxygen index range is 27-32 percent, the low smoke and low toxicity are realized, the high efficiency and stability are realized, the viscosity is controllable, and the problem that a plurality of phosphorus-containing monomers disclosed in the prior art cannot realize higher polymerization degree when the phosphorus content is increased is solved.
Detailed Description
The present invention will be described in further detail with reference to specific examples.
The molecular structure of the organophosphorus flame-retardant polyamide is shown as the following formula 1:
wherein R is selected from H, C1-C5Alkyl radical, C6-C10Aryl radical, C3-C10A heteroaryl group; r is preferably H, C1-C3Alkyl radical, C6-C8Aryl, or C3-C6A heteroaryl group;
R1、R2each independently selected fromC being chain, branched or cyclic1-C10Alkylene radical, C6-C15Arylene or aralkylene, C3-C10An ester group; r1、R2Each independently of the others is preferably straight-chain, branched or cyclic C1-C5Alkylene radical, C6-C10Arylene or aralkylene, C3-C8An ester group;
R3、R3、R5each independently selected from C3-C12Linear, branched or cyclic alkylene, C6-C10Arylene radical, C3-C10A heteroaryl group; r3、R4、R5Each independently is preferably C3-C8Linear, branched or cyclic alkylene, C6-C8Arylene radical, C3-C8A heteroaryl group;
R6is selected from C1-C10An alkylene group; r6Preferably C3-C9An alkylene group;
x represents 1 to 50; y represents 1 to 50; z represents 1 to 50; n represents 1 to 100; x is preferably from 2 to 30, y is preferably from 2 to 30, z is preferably from 2 to 30, and n is preferably from 2 to 80, more preferably from 5 to 50.
The preparation method of the organic phosphorus copolymerized flame-retardant polyamide specifically comprises the following steps:
(A) reacting an organic phosphorus flame-retardant monomer with diamine, preferably, leading amino to be excessive to generate a salt solution;
(B) reacting the reaction product of step (A) with a diacid and a diamine or a diamide salt and a lactam to produce an organophosphorus copolymerized flame retardant polyamide.
In step (A), the diamine-based monomer is preferably used in a slight excess so that the salt solution has a pH of 7 to 9. The reaction temperature is increased from room temperature to 40-70 ℃ within 5-20 min.
Preferably, the diamine monomer used in step (A) is hexamethylenediamine, decamethylenediamine, nonanediamine, undecanediamine, dodecanediamine, aliphatic C6-C20One or more of imino diamine, aromatic diamine and alicyclic diamine.
In the step (B), preferably, the polymerization monomers (diacid and diamine or diamine salt, lactam), the reaction product (salt or salt solution) of the step (a), the antioxidant, the catalyst, and deionized water are added into a reaction kettle, and the reaction temperature and pressure are controlled under nitrogen atmosphere to obtain the desired organophosphorus copolymerized flame retardant polyamide material.
In the step (B), further, the antioxidant is one or more of compounds such as p-phenylenediamine and dihydroquinoline, derivatives or polymers thereof, 2, 6-di-tert-butyl-4-methylphenol, bis (3, 5-di-tert-butyl-4-hydroxyphenyl) sulfide, pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] and the like.
Furthermore, the catalyst is one or more of sodium hypophosphite, methyl benzene sulfonic acid, a new ferrocene chiral polyamide ligand and the like.
Further preferably, the step (B) specifically includes the following steps:
a. adding a polymerization monomer, the reaction product obtained in the step (A), a catalyst, an antioxidant and deionized water into a reaction kettle, vacuumizing, and filling nitrogen for several times to ensure that the pressure in the kettle is 0.1-0.5MPa in the initial stage of reaction;
b. heating the reaction kettle to 200 ℃ and 250 ℃, and maintaining the reaction condition for 30-180min when the pressure is 1.6-2.1 MPa;
c. slowly releasing the pressure to normal pressure at the temperature of 230 ℃ and 280 ℃, then vacuumizing to-0.01 to-0.1 MPa, and copolymerizing for 10-180 min;
d. and finally, filling nitrogen, discharging materials, cooling, granulating, extracting and drying to obtain a final product.
Further, in step a, the addition amount of the polymerization monomer (diacid/diamine or diamine salt + lactam) is 8 to 100 times, preferably 10 to 40 times, and more preferably 12 to 30 times of the mass of the flame retardant, and the catalyst and the antioxidant are respectively 0.01 to 1.0 percent, preferably 0.05 to 0.5 percent, more preferably 0.08 to 0.2 percent, and more preferably about 1/1000 percent of the mass of the polymerization monomer (diacid/diamine or diamine salt + lactam). The amount of water added is preferably 10 to 60%, preferably 30 to 50%, of the polymerized monomers.
Further, in step a, theThe polymeric monomeric dibasic acid is, for example, one or more of adipic acid, sebacic acid, azelaic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, phthalic acid or derivatives thereof, and other aliphatic and aromatic dicarboxylic acids; the diamine compound is, for example, hexamethylenediamine, nonanediamine, decanediamine, undecanediamine, dodecanediamine, and aliphatic C6-C20One or more of an imino diamine, an aromatic diamine, or an alicyclic diamine; the above-mentioned bisamide salt compound is, for example, polyhexamethylene adipamide, polypentylene adipamide, polyhexamethylene azelamide, polyhexamethylene sebacamide, polyhexamethylene suberoyl, polyhexamethylene dodecanoylamide, polyhexamethylene suberoyl, etc. The lactam in the polymerization monomer is one or more of caprolactam, decanolactam, undecanolactam, dodecanolactam and various lactam monomers with lactam characteristics.
The examples of the invention are as follows:
the methods used in the following examples are conventional methods unless otherwise specified.
Materials, reagents and the like used in the following examples are commercially available unless otherwise specified. "%" is by mass fraction unless otherwise specified.
Example 1:
and (2) at the temperature of 60 ℃, mixing the flame-retardant monomer and hexamethylene diamine in an aqueous solution according to a molar ratio of 1:1.2 stirring and reacting for 0.5h, adjusting the pH value of the solution to 7.2, and drying to form salt. Adding a nylon 66 salt (hexamethylene adipamide salt) solution and caprolactam with the molar ratio of 1:1, the obtained salt accounting for 6.0 percent of the total mass of the caprolactam and the caprolactam, a catalyst sodium hypophosphite with the ratio of 1 per thousand, an antioxidant p-phenylenediamine and deionized water with the ratio of 40 percent into a reaction kettle, vacuumizing, filling nitrogen for 5 times, and finally keeping the pressure in the reaction kettle at 0.2 MPa. Heating the reaction kettle, keeping high-speed stirring, and keeping constant temperature and pressure for 1.5h when the temperature of the reaction kettle reaches 220 ℃ and the pressure is 1.8 MPa. Then the temperature is raised to 250 ℃, and the pressure is released to the normal pressure within 1 hour. Vacuumizing to-0.05 MPa, charging nitrogen to 0.2MPa after the stirring speed is reduced for a certain value and is stable, discharging the materials, cooling, granulating, extracting and drying to obtain a final product, wherein the relative viscosity of the final product is 2.6, the limited oxygen index is 28.3%, and the flame retardant grade reaches the UL94V-0 grade. Wherein the used organic phosphorus flame-retardant monomers are as follows:
example 2:
and (2) at 45 ℃, mixing the flame-retardant monomer and hexamethylene diamine in an aqueous solution according to a molar ratio of 1: 1.3 stirring and reacting for 1h, adjusting the pH value of the solution to 7.8, and drying to form salt. Preparing adipic acid and hexamethylene diamine according to a mass ratio of 1:1.2, adding decanolactam with a molar ratio of 1:0.6 to adipic acid, the obtained salt accounting for 7% of the total weight of the adipic acid, the hexamethylene diamine and the decanolactam, 1 per thousand of catalysts of methyl benzenesulfonic acid, 2, 6-di-tert-butyl-4-methylphenol and 35% of deionized water into a reaction kettle, vacuumizing, filling nitrogen for 3 times, and finally keeping the pressure in the reaction kettle at 0.3 MPa. Heating the reaction kettle, keeping high-speed stirring, and keeping constant temperature and pressure for 1.6h when the temperature of the reaction kettle reaches 215 ℃ and the pressure is 1.7 MPa. Then the temperature is raised to 240 ℃, and the pressure is released to the normal pressure within 1.5 h. Vacuumizing to-0.06 MPa, charging nitrogen to 0.3MPa after the stirring speed is reduced for a certain value and is stable, discharging the materials, cooling, granulating, extracting and drying to obtain the final product, wherein the relative viscosity of the final product is 2.35, the limited oxygen index is 29.2%, and the flame retardant grade reaches the UL94V-0 grade. Wherein the used organic phosphorus flame-retardant monomers are as follows:
example 3:
and (2) mixing the flame-retardant monomer and nonane diamine in an aqueous solution at the temperature of 60 ℃ according to the molar ratio of 1:1.5 stirring and reacting for 1h, adjusting the pH value of the solution to 7.6, and drying to form salt. Adding undecane diacid, hexamethylene diamine and dodecalactam with the molar ratio of 1:1.2:1, salt which is 8 percent of the total mass of the three monomers, catalyst sodium hypophosphite with the ratio of 1 per thousand, antioxidant bis (3, 5-di-tert-butyl-4-hydroxyphenyl) thioether and deionized water with the ratio of 50 percent into a reaction kettle, vacuumizing, filling nitrogen for 4 times, and finally keeping the pressure in the reaction kettle at 0.2 MPa. The reaction kettle is heated and kept stirring at a high speed. When the temperature of the reaction kettle reaches 225 ℃ and the pressure is 1.7MPa, the temperature and the pressure are constant for 2 hours. Then the temperature is raised to 255 ℃, and the pressure is released to the normal pressure within 2 hours. Vacuumizing to-0.09 MPa, introducing nitrogen to 0.3MPa after the stirring speed is reduced for a certain value and is stable, discharging the materials, cooling, granulating, extracting and drying to obtain a final product, wherein the relative viscosity of the final product is 2.5, the limited oxygen index is 31.4%, and the flame retardant grade reaches UL 94V-0. Wherein the used organic phosphorus flame-retardant monomers are as follows:
example 4:
mixing a flame retardant and hexamethylene diamine in an aqueous solution at a molar ratio of 1:1.2 stirring and reacting for 50min, adjusting the pH value of the solution to 7.4, and drying to form salt. Adding undecanedioic acid, octanediamine and undecanolactam monomers with the molar ratio of 1:1.1:0.5, the obtained salt accounting for 8 percent of the total mass of the three monomers, 1 per thousand of the catalyst of methyl benzenesulfonic acid, 1 per thousand of the antioxidant of tetra [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionic acid ] pentaerythritol ester and 40 percent of deionized water into a reaction kettle, vacuumizing, filling nitrogen for 3 times, and finally keeping the pressure in the reaction kettle at 0.35 MPa. The reaction kettle is heated and kept stirring at a high speed. When the temperature of the reaction kettle reaches 230 ℃ and the pressure is 1.8MPa, the temperature and the pressure are constant for 2 hours. Then the temperature is raised to 260 ℃, and the pressure is released to the normal pressure within 1 hour. Vacuumizing to-0.05 MPa, introducing nitrogen to 0.3MPa after the stirring speed is reduced for a certain value and is stable, discharging the materials, cooling, granulating, extracting and drying to obtain a final product, wherein the relative viscosity of the final product is 2.35, the limited oxygen index of the final product is 31.8 percent, and the flame retardant grade of the final product reaches UL 94V-0. Wherein the used organic phosphorus flame-retardant monomers are as follows:
example 5:
at the temperature of 62 ℃, the flame-retardant monomer and hexamethylene diamine are mixed in an aqueous solution according to the molar ratio of 1:1.2 stirring and reacting for 0.5h, adjusting the pH value of the solution to 7.8, and drying to form salt. Adding a nylon 66 salt (hexamethylene adipamide salt) solution and caprolactam with a molar ratio of 1:1.15, the obtained salt accounting for 10.0 percent of the total mass of the caprolactam and the caprolactam, a catalyst sodium hypophosphite with a ratio of 1 per thousand respectively, and an antioxidant p-phenylenediamine into a reaction kettle, vacuumizing, filling nitrogen for 5 times, and finally keeping the pressure in the reaction kettle at 0.2 MPa. Heating the reaction kettle, keeping high-speed stirring, and keeping constant temperature and pressure for 1.5h when the temperature of the reaction kettle reaches 235 ℃ and the pressure is 1.95 MPa. Then the temperature is raised to 260 ℃, and the pressure is released to the normal pressure within 1 hour. Vacuumizing to-0.05 MPa, charging nitrogen to 0.4MPa after the stirring speed is reduced for a certain value and is stable, discharging the materials, cooling, granulating, extracting and drying to obtain the final product, namely the organic phosphorus copolymerization flame-retardant polyamide composition, wherein the P content is 0.80-0.84 mass%, the relative viscosity is 2.25, the limited oxygen index is 32.6%, and the flame-retardant grade reaches the UL94V-0 grade. Wherein the organic phosphorus flame-retardant monomer is as follows:
1. preparation of the samples
Test specimens made of polyamide materials to which no flame retardant was added were referred to as "PA", and test specimens made of the organophosphorus flame retardant polyamide materials obtained in the above examples 1 to 5 were referred to as "FR-A" - "FR-E" in this order.
The test specimen preparation procedure for all the above-mentioned specimens is referred to GB/T9532-.
2. Limiting Oxygen Index (LOI) test
The limit oxygen index test refers to the standard GB/T2406.2-2009 combustion behavior determination by oxygen index method for plastics, and the limit oxygen index is determined by a type limit oxygen index determinator at room temperature. Spline specification: 80mm 10mm 4 mm.
UL-94 testing
The vertical combustion test refers to the standard of GB/T2408-2008 horizontal method and vertical method for testing the combustion performance of plastics, and is carried out at room temperature by adopting a CFZ-5 type vertical combustion tester. Spline specification: 125mm 13.2mm 3.2 mm. The sample strip is vertically fixed on the sample clamp, the part clamped at the upper end is 6mm, the distance between the lower end of the sample strip and absorbent cotton (4mm thick) is 300mm, flame is applied at the position 10mm from the bottom end of the sample strip, and the test data of the sample strip is recorded. After the specimen extinguishes, it is reignited according to the criteria in Table 1 below and the test data recorded.
TABLE 1 comparative standards for assay grade
4. Conclusion of the test
The flame retardant property test result of the embodiment shows that the existence of the organophosphorus flame retardant structure improves the flame retardant property of the polyamide. When the content of the flame-retardant monomer reaches more than 6 percent, the flame-retardant polyamide can pass the V-0 test of UL-94, and the LOI value is improved along with the flame-retardant polyamide. Therefore, the invention proves that the method is feasible and efficient for modifying the polyamide flame retardance by utilizing the reactive organic phosphorus flame retardant. The organic phosphorus copolymerization flame-retardant polyamide material obtained by the scheme provided by the invention has higher limited oxygen index and higher relative viscosity value. Due to the presence of end groups, conventional solid tackifying processes can be used to obtain a variety of desired viscosity values when higher viscosity materials are to be obtained.
The above description is only a preferred embodiment of the present invention, and does not limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.