CN114736369A - Modified nylon and preparation method thereof - Google Patents

Modified nylon and preparation method thereof Download PDF

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CN114736369A
CN114736369A CN202210581066.9A CN202210581066A CN114736369A CN 114736369 A CN114736369 A CN 114736369A CN 202210581066 A CN202210581066 A CN 202210581066A CN 114736369 A CN114736369 A CN 114736369A
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acid
monomer
modified nylon
melt viscosity
reacting
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CN114736369B (en
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潘凯
赵世坤
赵彪
邓建平
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Beijing University of Chemical Technology
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Beijing University of Chemical Technology
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    • C08G69/00Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
    • C08G69/02Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
    • C08G69/36Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from amino acids, polyamines and polycarboxylic acids

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Abstract

The invention discloses modified nylon and a preparation method thereof. The modified nylon has a structure shown in a formula (I), wherein a is 5, 6, 10 or 12; x, y and z are the number of repeating units and are integers of 1-20, R1Is an aromatic group. The modified nylon provided by the invention is high-temperature resistant, and has high strength and low relative viscosity.
Figure DDA0003662319090000011

Description

Modified nylon and preparation method thereof
Technical Field
The invention relates to modified nylon and a preparation method thereof.
Background
Most aliphatic polyamides (i.e., aliphatic nylons) have melting temperatures below 260 ℃ and cannot be used in high temperature environments. Aromatic rings are introduced into a polyamide main chain through molecular structure design, so that the flexibility of a polyamide molecular chain can be effectively reduced, and the glass transition temperature and the melting point are improved.
At present, the common high-temperature resistant nylon mainly comprises the following components: polyhexamethylene terephthalamide (PA6T), polynaphthalene terephthalamide (PA9T) and polynaphthalene terephthalamide (PA 10T). The melting temperature of PA6T is over 350 ℃, and direct synthesis and processing are difficult. Therefore, more PA6T is copolymerized with other components, so as to lower the melting temperature and increase the toughness of the material. Even so, in order to meet the long-term use in high temperature environment, the melting point of the PA6T copolymer is still kept at about 300 ℃, the viscosity is large, which puts strict requirements on the polymerization process, and the high-viscosity melt causes difficulties for heat transfer and mass transfer in the synthesis and processing processes. In order to solve the problem, a prepolymerization-screw extrusion process or a solid-phase tackifying process is usually adopted, but the process has a long preparation flow and low production efficiency, does not completely solve the problem of high melt viscosity, and is difficult to realize the requirement of ultrathin injection molding. Therefore, it is necessary to provide a modified nylon having a low relative viscosity, high temperature resistance and substantially no decrease in strength, and a method for preparing the same.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a modified nylon. The obtained modified nylon has high temperature resistance and high strength. In addition, its relative viscosity is small. The invention also aims to provide the preparation method of the modified nylon, which has stable process, moderate viscosity during polycondensation, easy operation and contribution to industrial production.
The invention adopts the following technical scheme to achieve the purpose.
In one aspect, the invention provides a modified nylon having a structure represented by formula (I):
Figure BDA0003662319070000021
in formula (I), a is 5, 6, 10 or 12; x, y and z are numbers of repeating units respectively and are integers of 1-20 respectively;
R1is an aromatic group selected from one of the following groups:
Figure BDA0003662319070000022
R2one selected from the following groups:
Figure BDA0003662319070000023
R3one selected from the following groups:
Figure BDA0003662319070000024
wherein R is1And R3Different.
The modified nylon with the structure has high temperature resistance, improved thermodynamic properties including melting point, crystallization temperature and thermal decomposition temperature, better mechanical property, higher strength and lower relative viscosity.
Wherein a is 5, 6, 10 or 12, preferably a is 5, 6 or 10. x, y and z may be integers of 1 to 20, preferably 4 to 20, and more preferably 5 to 18, respectively.
According to the modified nylon of the present invention, preferably:
R1one selected from the following groups:
Figure BDA0003662319070000031
R2is composed of
Figure BDA0003662319070000032
R3One selected from the following groups:
Figure BDA0003662319070000033
according to the modified nylon of the present invention, preferably:
R1is composed of
Figure BDA0003662319070000034
R3Is composed of
Figure BDA0003662319070000035
According to one embodiment of the invention, R1Is composed of
Figure BDA0003662319070000036
R2Is composed of
Figure BDA0003662319070000037
R3Is composed of
Figure BDA0003662319070000038
In another aspect, the present invention also provides a method for preparing the modified nylon, which comprises the following steps:
(1) under the protection of inert gas, adding a diamine monomer, an aromatic dibasic acid monomer, a third monomer, a melt viscosity regulator, a molecular weight regulator, a catalyst, an auxiliary agent and water into a reaction kettle to obtain a first mixture;
(2) reacting the first mixture at 55-95 ℃ for 0.5-2 h; then reacting for 0.5-3 h at 115-165 ℃; obtaining a second mixture;
(3) reacting the second mixture at 190-215 ℃ and 1.2-1.6 MPa for 0.5-2 h to obtain a first prepolymer; reacting the first prepolymer at 210-255 ℃ and 1.8-2.2 MPa for 2-5 h to obtain a second prepolymer;
(4) heating the second prepolymer to 290-325 ℃ within 2-5 h, and exhausting the reaction kettle to normal pressure; then vacuumizing until the vacuum degree in the reaction kettle is-0.6 to-0.9 MPa, and continuing to react until the torque reaches 60-100 Nm to obtain modified nylon;
wherein, the diamine monomer is selected from one of pentanediamine, hexanediamine, decanediamine and dodecanediamine; the aromatic dibasic acid monomer is one selected from terephthalic acid, isophthalic acid and 2, 6-naphthalene dicarboxylic acid; the third monomer is caprolactam or adipic acid; the melt viscosity modifier is selected from one of isophthalic acid, 1, 4-cyclohexanedicarboxylic acid, methylcyclohexanediamine, 4 ' -diaminodicyclohexylmethane and 3,3 ' -dimethyl-4, 4 ' -diaminodicyclohexylmethane; the molecular weight regulator is selected from one of formic acid, acetic acid, benzoic acid and stearic acid.
The modified nylon has the advantages of reducing the viscosity of the modified nylon, enabling the modified nylon to have higher mechanical properties such as tensile strength, bending strength and the like, and also being capable of enabling the modified nylon to have higher melting point, decomposition temperature and the like and to resist high temperature.
In the present invention, the diamine monomer is one selected from the group consisting of pentanediamine, hexanediamine, decanediamine and dodecanediamine; preferably one selected from the group consisting of pentamethylenediamine, hexamethylenediamine and decamethylenediamine, and more preferably one selected from the group consisting of hexamethylenediamine and decamethylenediamine.
The aromatic dibasic acid monomer may be one selected from terephthalic acid, isophthalic acid and 2, 6-naphthalenedicarboxylic acid, preferably selected from terephthalic acid or 2, 6-naphthalenedicarboxylic acid, more preferably terephthalic acid. The third monomer may be caprolactam or adipic acid, preferably caprolactam.
The melt viscosity modifier may be one selected from isophthalic acid, 1, 4-cyclohexanedicarboxylic acid, methylcyclohexanediamine, 4 ' -diaminodicyclohexylmethane and 3,3 ' -dimethyl-4, 4 ' -diaminodicyclohexylmethane; preferably selected from isophthalic acid, methylcyclohexanediamine or 1, 4-cyclohexanedicarboxylic acid; more preferably isophthalic acid. The inventor believes that the addition of the melt viscosity regulator can reduce the regularity of chain segments, increase the shear sensitivity of the copolymer, improve the high-temperature fluidity and effectively solve the problems of large melt viscosity, uneven mixing and poor mass and heat transfer effects in the later reaction stage of the direct polycondensation method; the melt viscosity in the later reaction period can be effectively reduced, and the uniform stirring and smooth discharging in the vacuum polycondensation stage are ensured. And the melt viscosity regulator is controlled within a specific proportion range, so that the obtained modified nylon has the advantages of no reduction of mechanical properties, higher strength, better high temperature resistance, higher melting point and decomposition temperature. The prepared high-temperature-resistant modified nylon is more suitable for complex structure and thin-wall injection molding.
The molecular weight regulator is selected from one of formic acid, acetic acid, benzoic acid and stearic acid, preferably from benzoic acid or stearic acid, and more preferably benzoic acid.
According to a preferred embodiment of the present invention, the diamine monomer is hexamethylenediamine, the aromatic diacid monomer is terephthalic acid, the third monomer is caprolactam, the melt viscosity modifier is isophthalic acid, and the molecular weight modifier is benzoic acid.
The catalyst is preferably a mixture of phosphoric acid, sodium dihydrogen phosphate and sodium hypophosphite, and the weight ratio of the phosphoric acid, the sodium dihydrogen phosphate and the sodium hypophosphite is 1-3: 1-4: 2-7, and preferably 2-3: 2-4: 2-6. This is advantageous in ensuring a uniform catalytic effect in the various stages of the direct polycondensation.
The auxiliary agent comprises a stabilizer and/or a lubricant. In certain embodiments, the adjuvant is a lubricant. The stabilizer is selected from one or more of a light stabilizer SEED, an ultraviolet light absorber UV3346, an antioxidant 1098 and an antioxidant 626, and preferably, the stabilizer is selected from one of the light stabilizer SEED, the ultraviolet light absorber UV3346, the antioxidant 1098 and the antioxidant 626. The lubricant may be those known in the art, and preferably, the lubricant is silicone oil. The water can be deionized water, distilled water, or purified water; preferably deionized water.
In the invention, the weight ratio of the diamine monomer, the aromatic diacid monomer, the third monomer, the melt viscosity regulator, the molecular weight regulator, the catalyst, the stabilizer, the lubricant and the water can be 89-105: 110-186.5: 24-66: 11-22: 2-4: 5-15: 3-9: 2-9: 106-130, preferably 89-100: 115-170: 30-66: 11-18: 2-4: 7-15: 3-9: 2-9: 106-125, more preferably 89-100: 115-145: 30-65: 11-16: 2-4: 9-14: 3-9: 2-9: 106-125.
In the step (1), the inert gas may be one or more selected from nitrogen, argon or helium, preferably nitrogen, argon or helium, more preferably nitrogen. The inert gas can be used for replacing the air in the reaction kettle for 3-5 times to eliminate the interference of oxygen, and then the inert gas with the pressure of 0.9-1.2 MPa can be filled, so that the solubility of the monomer is increased, and the diamine monomer is prevented from volatilizing.
In the step (2), the first mixture is reacted at 55-95 ℃ for 0.5-2 h, preferably, the first mixture is reacted at 60-90 ℃ for 0.5-1 h.
And then reacting for 0.5-3 h at 115-165 ℃, preferably for 0.5-2 h at 120-160 ℃ to obtain a second mixture. The inventor finds that, on the one hand, the salt formation of the diamine monomer and the aromatic diacid monomer can be facilitated, and the volatilization of the diamine monomer can be prevented; on the other hand, the stepped heating mode is beneficial to mixing of different comonomers, so that the distribution of the copolymerization chain segment is more uniform, and the effect of the copolymerization viscosity regulator is fully exerted.
In the step (3), reacting the second mixture at 190-215 ℃ and 1.2-1.6 MPa for 0.5-2 h to obtain a first prepolymer; in the step, the reaction temperature is preferably 190-210 ℃, the reaction pressure is preferably 1.3-1.5 MPa, and the reaction time is preferably 0.5-1 h. This facilitates the prepolymerization of the third monomer.
Reacting the first prepolymer at 210-255 ℃ and 1.8-2.2 MPa for 2-5 h to obtain a second prepolymer; in the step, the reaction temperature is preferably 210-250 ℃, the reaction pressure is preferably 1.8-2.1 MPa, the reaction time is preferably 2-4 h, proper exhaust can be realized in the process, and the diamine monomer and the aromatic diacid monomer can be prepolymerized and copolymerized with a third monomer.
In the step (4), the temperature rise rate is controlled to gradually rise, and meanwhile, the gas is slowly released. Heating to 290-325 ℃ within 2-5 h, and exhausting to normal pressure; the air release rate is adjusted by collecting the drained condensed water in the process. Preferably, the temperature is raised to 290-320 ℃ within 2-4 hours, and the gas is exhausted to the normal pressure. In the invention, the water content in the kettle is judged by combining the water discharge with the relation between the temperature in the kettle and the saturated vapor pressure so as to further obtain the reaction degree, the temperature and the air release rate are adjusted in time, the reaction balance of the polycondensation reaction is ensured to move slowly in the forward direction, the reaction degree is increased uniformly, and the molecular weight is kept uniform.
And then vacuumizing at the constant temperature of 290-320 ℃. Vacuumizing until the vacuum degree in the reaction kettle is-0.6 to-0.9 MPa, and continuously reacting for 5 to 15min until the torque reaches 60 to 100Nm to obtain the modified nylon. Preferably, the reaction is continued for 5 to 10min until the torque reaches 70 to 90 Nm.
In the invention, after the torque reaches the set requirement, stirring is stopped, nitrogen gas is filled to recover normal pressure, and the modified nylon is obtained by discharging, water cooling, granulating and drying.
According to the preparation method of the present invention, preferably:
the aromatic diacid monomer is selected from one of terephthalic acid and 2, 6-naphthalene dicarboxylic acid;
the third monomer is caprolactam;
the melt viscosity regulator is selected from isophthalic acid, methylcyclohexanediamine or 1, 4-cyclohexanedicarboxylic acid;
the molecular weight regulator is selected from benzoic acid and stearic acid.
According to the preparation method of the present invention, preferably:
the aromatic dibasic acid monomer is terephthalic acid;
the melt viscosity regulator is isophthalic acid;
the molecular weight regulator is benzoic acid.
According to the preparation method of the present invention, preferably:
the auxiliary agent comprises a stabilizer and/or a lubricant;
the weight ratio of the diamine monomer, the aromatic diacid monomer, the third monomer, the melt viscosity regulator, the molecular weight regulator, the catalyst, the stabilizer, the lubricant and the water is 89-105: 110-186.5: 24-66: 11-22: 2-4: 5-15: 3-9: 2-9: 106-130. Thus being beneficial to obtaining the copolymer modified nylon with high temperature resistance, high strength and small relative viscosity.
In the present invention, the relative viscosity of the copolymer was measured using a Zhongwang ISV-400 autoviscometer, the solvent was concentrated sulfuric acid, the solution concentration was 0.1g/dL, and the temperature was 25 ℃. The relative viscosity of the copolymer modified nylon is 2.0-2.5, preferably 2.0-2.4.
According to the preparation method provided by the invention, preferably, the catalyst consists of phosphoric acid, sodium dihydrogen phosphate and sodium hypophosphite in a weight ratio of 1-3: 1-4: 2-7. This facilitates a more uniform catalysis of the various stages of polycondensation.
According to the preparation method of the invention, preferably, the stabilizer is one or more selected from a light stabilizer SEED, an ultraviolet absorber UV3346, an antioxidant 1098 and an antioxidant 626.
According to the preparation method provided by the invention, preferably, in the step (4), the reaction is continued for 5-10 min until the torque reaches 70-90 Nm. Thus being beneficial to leading the obtained modified nylon to have higher strength and high temperature resistance.
The modified nylon has the advantages of good high temperature resistance, high melting point, high thermal decomposition temperature and low relative viscosity, can keep good mechanical property, and has high tensile strength and bending strength. The preparation method has the advantages of stable process, small melt viscosity in the later polymerization stage, easy stirring, smooth discharging and contribution to industrial production. Furthermore, the preparation method of the invention is beneficial to improving the high temperature resistance of the modified nylon product, reducing the viscosity of the product, improving the fluidity and not reducing the strength by controlling the diamine monomer, the aromatic diacid monomer, the third monomer, the melt viscosity regulator, the molecular weight regulator and the like within a specific proportioning range.
Drawings
FIG. 1 is a graph showing the results of relative viscosity of nylons obtained in examples 1 to 3 of the present invention and comparative example 1.
FIG. 2 is a graph showing the results of melt flow rates of nylons obtained in examples 1 to 3 of the present invention and comparative example 1.
Detailed Description
The present invention will be further described with reference to specific embodiments, but the scope of the present invention is not limited thereto.
The following describes the analysis or test method:
(1) preparation of the samples
Test bars for tensile, flexural and impact properties were prepared according to GB/T9352-2008 compression Molding of Plastic thermoplastic Material specimens. Firstly, the prepared modified nylon resin is dried for 6 hours in vacuum at 100 ℃, a sample strip is injected by a WZS10 type injection molding machine, the temperature of a charging barrel is set to be 20 ℃ above the melting point, the mold temperature is 80 ℃, and the injection pressure is 7 MPa.
(2) Thermodynamic property test
Adopting a relaxation-resistant DSC 200F3 differential scanning calorimeter to test the melting point of a sample, heating to 350 ℃ at a heating rate of 20 ℃/min in a nitrogen atmosphere, keeping the temperature for 5min, eliminating the thermal history, cooling to 50 ℃ at a cooling rate of 10 ℃/min, and finally heating to 350 ℃ at a heating rate of 10 ℃/min;
and (3) measuring the thermal decomposition temperature of the sample in a nitrogen atmosphere by adopting a TA TGA 5500 thermogravimetric analyzer, wherein the heating rate is 10 ℃/min, and the temperature range is 50-700 ℃.
(3) Mechanical Property test
Measuring the tensile and bending properties of different sample bars by using an Instron 5567 universal tester, wherein the tensile rate is set to be 5mm/min, and the temperature is 25 ℃; the pressing rate of bending is 2mm/min, the span is 64mm, the bending deflection is 6%, and the temperature is 25 ℃.
(4) Characterization of flow Properties
The relative viscosity of different samples is measured by adopting a Zhongwang ISV-400 automatic viscometer, the solvent is concentrated sulfuric acid, the concentration of the solution is 0.1g/dL, and the temperature is 25 ℃.
The melt flow rate of different samples is measured by a Vico WKT-400 melt index meter under the test condition of 320 ℃ and the load of 2.16 Kg.
In the examples and comparative examples of the present invention, parts are by weight unless otherwise specified.
Examples 1 to 3 and comparative examples 1 to 5
The materials were charged according to the charging table of table 1:
(1) adding hexamethylene diamine, terephthalic acid, isophthalic acid, benzoic acid, caprolactam, phosphoric acid, sodium hypophosphite monohydrate, disodium hydrogen phosphate and silicone oil into deionized water for dispersion to form a pasty raw material, and transferring the pasty raw material into a reaction kettle; replacing air in the reaction kettle for 3 times by using inert gas, eliminating the interference of oxygen, and finally filling 0.9MPa of inert gas to increase the solubility of the monomer and prevent diamine from volatilizing; a first mixture is obtained.
(2) Starting stirring and heating, and reacting the first mixture at 100rpm and 80 ℃ for 1h to salify the diamine and the dibasic acid; then heating, reacting for 1h at 150 ℃, and performing enhanced salt formation to obtain a second mixture;
(3) then heating to 210 ℃, properly adjusting exhaust, reacting the second mixture for 1 hour at 210 ℃ and 1.5MPa, and carrying out prepolymerization on a third monomer to obtain a first prepolymer; continuously heating to 220 ℃, and reacting the first prepolymer for 2 hours at 220 ℃ and 1.9MPa to obtain a second prepolymer;
(4) controlling the temperature rise rate to gradually rise, simultaneously opening a pressure release valve to slowly release gas, raising the temperature to 310 ℃ within 4h, releasing gas to normal pressure, and adjusting the gas release rate by calculating the proportion of collected and discharged condensed water and added water during the period so as to ensure that the balance is stably moved in the forward direction, thereby obtaining a high-temperature resistant prepolymer with uniformly distributed molecular chains; slowly vacuumizing at the constant temperature at the speed of 0.01MPa/min until the vacuum degree in the reaction kettle reaches-0.8 MPa, continuously reacting for 5-10 min until the torque reaches 80Nm, stopping stirring, introducing nitrogen to recover the normal pressure, discharging, water cooling, granulating and drying to obtain modified nylon; wherein, PA6 in the modified nylon product accounts for 40 percent. The product of examples 1 to 3 was designated as PA 6T/6I/6. The results of the thermodynamic and mechanical properties are shown in Table 2. The results of the melt index and relative viscosity tests of examples 1-3 and comparative example 1 are shown in FIGS. 1 and 2.
Comparative example 6
The same as example 1 except for the following settings:
step (2): starting stirring and heating, reacting the raw materials at constant temperature of 100rpm and 80 ℃ for 1h to obtain a first mixture, and then directly heating to 210 ℃ for prepolymerization. The test results are shown in Table 2.
TABLE 1 feeding table
Figure BDA0003662319070000111
TABLE 2 test results
Figure BDA0003662319070000121
As can be seen from comparison of examples 1-3 and comparative example 1, when the amount of the aromatic dibasic acid is relatively increased without adding the melt viscosity modifier of isophthalic acid and the molecular weight modifier of benzoic acid, the thermodynamic properties of the obtained nylon, including the melting point, the crystallization temperature and the decomposition temperature, are reduced, and the mechanical properties, including the tensile strength, the flexural strength and the flexural modulus, are also reduced. The reason may be that the melting point of the linear aliphatic nylon PA6 is low, the regularity of the high segment of the copolymer component is worse, the crystallinity is low, and therefore the melting temperature is lowered, and the decomposition temperature and the tensile strength are lowered because the linear aliphatic PA6 is more likely to break the chain than the aromatic PA6T and PA 6I. Examples 1-3 show that the higher the aromatic ring content in the copolymer, the higher the melting point, the better the heat resistance, so that the regulation and control of modified nylon with different properties can be realized by adjusting the ratio of aromatic dicarboxylic acid and aliphatic comonomer, so as to face the application in different fields.
As can be seen from comparison of examples 1-3 and comparative example 2, the melting point of the modified nylon can be adjusted by only using the melt viscosity modifier isophthalic acid as a third comonomer, and the overall performance of the modified nylon is weaker than that of a terpolymer material due to higher rigidity and steric hindrance, but the chain segment regularity of the modified nylon is poor, so that the obtained molecular crystallinity is low, and a relatively transparent product can be obtained.
As can be seen from the comparison between examples 1 to 3 and comparative examples 3 to 5, if the amount ratio of the aromatic dibasic acid monomer terephthalic acid to the melt viscosity modifier isophthalic acid is not within the weight ratio range of the present invention, the thermodynamic properties of the resulting nylon product will be reduced, including the melting point, the crystallization temperature, and the decomposition temperature, and the tensile strength in mechanical properties will be reduced, but the flexural strength and flexural modulus will not be substantially reduced. This may be because excessive introduction of asymmetric structure lowers the melting point and tensile strength of the resulting product because the complex conformational transition and irregularity of the segments lowers the crystallinity of the resulting nylon, while the increase in flexural strength may be because more of the form of conformational transition enables the resulting nylon molecular chains to stretch under tension.
As can be seen from the comparison between example 1 and comparative example 6, the reduction of the overall performance of the product is caused by the direct heating for polycondensation after the salt formation at 80 ℃, and the reduction of the melting point and the thermal decomposition temperature may be caused by the uneven mixing of the monomers before the prepolymerization and the uneven distribution of the molecular chains due to the large difference of the reactivity of the monomers. The mechanical properties are reduced probably because, after salt formation, the direct prepolymerization leads to the volatilization of a portion of the diamine, which affects the molar ratio of the monomers and causes the molecular weight to decrease.
Example 4
The only difference from example 1 is: 14.63 parts of 1, 4-cyclohexanedicarboxylic acid were used instead of 14.30 parts of isophthalic acid. The product of example 4 was noted as PA 6T/6C/6. The test results are shown in Table 3.
TABLE 3
Figure BDA0003662319070000131
The present invention is not limited to the above-described embodiments, and any variations, modifications, and alterations that may occur to those skilled in the art may fall within the scope of the present invention without departing from the spirit of the present invention.

Claims (10)

1. A modified nylon having a structure represented by formula (I):
Figure FDA0003662319060000011
in formula (I), a is 5, 6, 10 or 12; x, y and z are numbers of repeating units respectively and are integers of 1-20 respectively;
R1is an aromatic group selected from one of the following groups:
Figure FDA0003662319060000012
R2one selected from the following groups:
Figure FDA0003662319060000013
R3selected from the group consisting ofOne of the following:
Figure FDA0003662319060000014
wherein R is1And R3Different.
2. The modified nylon of claim 1, wherein:
R1one selected from the following groups:
Figure FDA0003662319060000015
R2is composed of
Figure FDA0003662319060000016
R3One selected from the following groups:
Figure FDA0003662319060000021
3. the modified nylon of claim 1, wherein:
R1is composed of
Figure FDA0003662319060000022
R3Is composed of
Figure FDA0003662319060000023
4. A method for preparing the modified nylon according to any one of claims 1 to 3, comprising the steps of:
(1) under the protection of inert gas, adding a diamine monomer, an aromatic dibasic acid monomer, a third monomer, a melt viscosity regulator, a molecular weight regulator, a catalyst, an auxiliary agent and water into a reaction kettle to obtain a first mixture;
(2) reacting the first mixture at 55-95 ℃ for 0.5-2 h; then reacting for 0.5-3 h at 115-165 ℃; obtaining a second mixture;
(3) reacting the second mixture at 190-215 ℃ and 1.2-1.6 MPa for 0.5-2 h to obtain a first prepolymer; reacting the first prepolymer at 210-255 ℃ and 1.8-2.2 MPa for 2-5 h to obtain a second prepolymer;
(4) heating the second prepolymer to 290-325 ℃ within 2-5 h, and exhausting the reaction kettle to normal pressure; then vacuumizing until the vacuum degree in the reaction kettle is-0.6 to-0.9 MPa, and continuously reacting until the torque reaches 60-100 Nm to obtain modified nylon;
wherein, the diamine monomer is selected from one of pentanediamine, hexanediamine, decanediamine and dodecanediamine;
wherein the aromatic dibasic acid monomer is one selected from terephthalic acid, isophthalic acid and 2, 6-naphthalene dicarboxylic acid;
wherein the third monomer is caprolactam or adipic acid;
wherein the melt viscosity modifier is selected from one of isophthalic acid, 1, 4-cyclohexanedicarboxylic acid, methylcyclohexanediamine, 4 ' -diaminodicyclohexylmethane and 3,3 ' -dimethyl-4, 4 ' -diaminodicyclohexylmethane;
wherein the molecular weight regulator is selected from one of formic acid, acetic acid, benzoic acid and stearic acid.
5. The method of claim 1, wherein:
the diamine monomer is one of pentanediamine, hexanediamine and decanediamine;
the aromatic diacid monomer is selected from one of terephthalic acid and 2, 6-naphthalene dicarboxylic acid;
the third monomer is caprolactam;
the melt viscosity regulator is selected from isophthalic acid, methylcyclohexanediamine or 1, 4-cyclohexanedicarboxylic acid;
the molecular weight regulator is selected from benzoic acid and stearic acid.
6. The production method according to claim 1, characterized in that:
the diamine monomer is hexamethylene diamine or decamethylene diamine;
the aromatic dibasic acid monomer is terephthalic acid;
the melt viscosity regulator is isophthalic acid;
the molecular weight regulator is benzoic acid.
7. The production method according to claim 1, characterized in that:
the auxiliary agent comprises a stabilizer and/or a lubricant;
the weight ratio of the diamine monomer, the aromatic diacid monomer, the third monomer, the melt viscosity regulator, the molecular weight regulator, the catalyst, the stabilizer, the lubricant and the water is 89-105: 110-186.5: 24-66: 11-22: 2-4: 5-15: 3-9: 2-9: 106-130.
8. The method of claim 7, wherein the catalyst is composed of phosphoric acid, sodium dihydrogen phosphate and sodium hypophosphite in a weight ratio of 1-3: 1-4: 2-7.
9. The preparation method of claim 7, wherein the stabilizer is one or more selected from the group consisting of a light stabilizer SEED, an ultraviolet absorber UV3346, an antioxidant 1098 and an antioxidant 626.
10. The method according to claim 1, wherein in the step (4), the reaction is continued for 5 to 10min until the torque reaches 70 to 90 Nm.
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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015057557A1 (en) * 2013-10-16 2015-04-23 E. I. Du Pont De Nemours And Company Process for making semi-aromatic terpolyamide
CN105085903A (en) * 2015-09-14 2015-11-25 北京旭阳化工技术研究院有限公司 High-temperature-resistant branched polyamide block copolymer and preparation method thereof
CN107446129A (en) * 2017-08-16 2017-12-08 株洲时代新材料科技股份有限公司 A kind of preparation method of anti-aging semi-aromatic nylon resin

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015057557A1 (en) * 2013-10-16 2015-04-23 E. I. Du Pont De Nemours And Company Process for making semi-aromatic terpolyamide
CN105085903A (en) * 2015-09-14 2015-11-25 北京旭阳化工技术研究院有限公司 High-temperature-resistant branched polyamide block copolymer and preparation method thereof
CN107446129A (en) * 2017-08-16 2017-12-08 株洲时代新材料科技股份有限公司 A kind of preparation method of anti-aging semi-aromatic nylon resin

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