Semi-aromatic furyl copolyamide and preparation method thereof

Abstract

The invention discloses semi-aromatic furyl copolyamide and a preparation method thereof, and is characterized in that dimethyl furandicarboxylate, 1, 4-butanediamine and a third comonomer are used as raw materials, water is used as a prepolymerization medium, and the semi-aromatic furyl copolyamide is obtained through prepolymerization and direct melt polycondensation. According to the method, by introducing a third comonomer, the thermal stability and processability of furyl polyamide are improved. Water is used as a solvent in the prepolymerization process and is green and environment-friendly; according to the preparation method of the semi-aromatic furyl copolyamide, the copolymerization raw material is prepared into an oligomer with a certain molecular weight under a mild prepolymerization condition, and then the oligomer is heated for melt polycondensation reaction, so that the loss of unstable comonomers is avoided, the stability of the melt polycondensation raw material is improved, and the semi-aromatic furyl copolyamide with more stable performance is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of polyamide materials, and in particular to a semi-aromatic furan-based copolyamide and a preparation method thereof. Background Art

[0002] The present invention relates to a novel semi-aromatic furan-based copolyamide and a preparation method thereof, wherein the material combines the good processing properties of aliphatic polyamides and the excellent thermal stability of fully aromatic polyamides. In modern industry, the requirements for material properties are increasing day by day. Traditional aliphatic polyamides such as nylon 6 and nylon 66 are widely used due to their good toughness and processing properties, but they still have certain limitations in terms of strength, elastic modulus and heat resistance. On the other hand, fully aromatic polyamides such as Kevlar (poly(p-phenylene terephthalamide)) and Nomex (poly(m-phenylene isophthalamide)) show excellent mechanical properties and thermal stability, but their high cost and processing difficulty limit their application in a wider range of fields.

[0003] In order to solve this contradiction, researchers are committed to developing a new type of material that can maintain low cost and good processing performance while having high mechanical properties and heat resistance. Semi-aromatic furan-based polyamides are expected to achieve the above goals by introducing aromatic rings into the molecular structure while retaining some aliphatic segments. This type of material can not only provide higher strength and elastic modulus than aliphatic polyamides, but also improve the heat resistance and chemical stability of the material. At the same time, compared with fully aromatic polyamides, it has lower cost and easier processing. At present, furan dicarboxylic acid and its derivatives based on biomass sources have shown great application potential in the synthesis of polymers as substitutes for traditional petroleum-based terephthalic acid or isophthalic acid. And due to the inherent strong polarity of the furan ring, furan-based polyamides can be directly prepared from furan dicarboxylic acid dimethyl ester and diamine by prepolymerization combined with melt polycondensation. Compared with the traditional petroleum-based semi-aromatic polyamides through salt formation combined with solid phase polycondensation, it has more cost and time advantages. Therefore, it is of great significance to develop semi-aromatic furan-based copolyamides that meet different application scenarios.

[0004] In terms of technical background, in recent years, with the continuous progress of polymerization reaction engineering and technology, the synthesis and modification of semi-aromatic polyamides have made significant progress. The present invention effectively regulates the physical and chemical properties of the material by designing the monomer structure and optimizing the polymerization process, so that it can meet the needs of different application fields, such as the automotive manufacturing industry, the electrical and electronic industry, and sporting goods.

[0005] Based on this background, the present invention proposes an innovative semi-aromatic furan-based copolyamide material and its preparation scheme, aiming to further improve the comprehensive performance of the material, improve its mechanical properties and processing properties by introducing long carbon chain diamines / diacids and branched diamines, or introduce rigid structural segments to enhance its thermal stability and mechanical strength, so as to expand the application scenarios of furan-based polyamide, broaden its application range, and provide more competitive material options for related industries. It can further replace the application of petroleum-based semi-aromatic polyamide in different scenarios, thereby realizing the preparation of green polyamide, reducing carbon emissions, and helping to achieve the "dual carbon" goal. Summary of the invention

[0006] The present invention aims to solve the problems of poor stability of furan-based polyamide monomers and difficulty in material processing, and provides a method for preparing copolyamide by prepolymerization-direct melt polycondensation, which avoids the use of organic solvents and functionalizes the furan-based polyamide by adding a third comonomer, thus greatly broadening its application scenarios. In the copolyamide based on furan-based polyamide, as the proportion of copolymerized diamine increases, its thermal stability and mechanical properties are significantly improved.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The present invention discloses a semi-aromatic furan-based copolyamide and a preparation method thereof, comprising the following contents:

[0009] A semi-aromatic furan-based copolyamide and a preparation method thereof. 1,4-butanediamine, dimethyl furandicarboxylate and a third comonomer are used as raw materials to prepare the semi-aromatic furan-based copolyamide through prepolymerization and direct melt polycondensation reaction.

[0010] The third comonomer is one or more of an aliphatic dibasic acid or diamine having a carbon chain length of 4 to 12 carbon atoms, aromatic isophthalic acid (IPA) or metaphenylenediamine (MPDA), a branched diamine (trimethylhexamethylenediamine) (TMD), or an alicyclic diamine (isophoronediamine (IPDA), meta-cyclohexyldimethylamine (CHDM)).

[0011] The molar ratio of the 1,4-butanediamine is 10% to 90% of the molar amount of the diamine in the raw material; the molar ratio of the dimethyl furandicarboxylate is 10% to 90% of the molar amount of the diester (diacid) in the raw material.

[0012] A semi-aromatic furan-based copolyamide and a preparation method thereof, comprising the following steps:

[0013] Add the comonomer of polyamide, water and catalyst into the polymerization reactor, fill with 0.1-0.4MPa argon, react at 60-80℃ for 1-2h, heat to 130-160℃ and maintain pressure for 1-6h, slowly reduce pressure to -0.1MPa for dehydration, react at 170-190℃ for 1-3h, heat to 230-260℃ for condensation for 1-6h.

[0014] The molar ratio of diester (diacid) to diamine in the monomer is 1±0.02:1±0.05.

[0015] The amount of water used as the prepolymerization medium is 100-200% of the sum of the mass of the diester (diacid) and the diamine.

[0016] The method is characterized in that the prepolymerization stage is controlled at 60-80° C. for 1-3 hours, and then the temperature is raised to 130-190° C. for 1-6 hours.

[0017] The polycondensation temperature in the polycondensation process is selected within a temperature range of 20-30° C., which is 1.5 times higher than the glass transition temperature.

[0018] The beneficial effects of the present invention are:

[0019] (1) The modification method of the semi-aromatic furan-based copolyamide proposed in the present invention realizes the continuous preparation of polyamide. Compared with the traditional salt-forming polymerization combined with solid-phase polycondensation, it greatly simplifies the process flow and is more conducive to industrial scale-up.

[0020] (2) In the present invention, the low-temperature prepolymerization and melt polycondensation temperature are controlled and adjusted according to the characteristics of the comonomer, which greatly reduces the occurrence of reaction side reactions and avoids the loss of unstable comonomers. Compared with the traditional polymerization method, a semi-aromatic furan-based copolyamide with a higher molecular weight is obtained.

[0021] (3) The present invention uses water as the prepolymerization medium and ionic liquid catalyzes ester amine exchange to prepare the semi-aromatic furan-based copolyamide, thereby avoiding the use of organic solvents. Compared with traditional solution polycondensation or bulk polymerization, the prepolymerization reaction more fully avoids the loss of monomers.

[0022] (4) The present invention purposefully adjusts the structure and properties of the semi-aromatic furan-based copolyamide by introducing a third comonomer, thereby obtaining a series of furan-based copolyamides with adjustable properties, which greatly broadens its application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The furan-based copolyamide PA4F / 46 obtained in the specific embodiment 2 of the present invention 1 H-NMR.

[0024] Figure 2The furan-based copolyamide PA4F / 46 obtained in the specific embodiment 2 of the present invention 13 C-NMR.

[0025] Figure 3 This is the TGA curve of the furan-based copolyamide PA4F / CHF obtained in the seventh embodiment of the present invention.

[0026] Figure 4 This is the DSC curve of the furan-based copolyamide PA4F / CHF obtained in the eighth embodiment of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described below with reference to specific embodiments. However, the application of the present invention is not limited to the scope listed in the embodiments. Without departing from the scope of the preceding and following purposes, any changes in implementation are included in the technical scope of the present invention.

[0028] Example 1

[0029] A semi-aromatic furan-based copolyamide (poly(butylene furan dicarboxyl) / trimethylhexamethylene furan dicarboxyl) (PA4F / TMF) and a preparation method thereof, characterized in that the preparation method comprises the following steps:

[0030] (1) 55.24 g of dimethyl furandicarboxylate, 19.44 g of 1,4-butanediamine, 14.96 g of trimethylhexamethylenediamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 132.19 g of deionized water were added to a 250 ml stirred autoclave, and the air in the system was repeatedly replaced with argon three times, and then the system was pressurized to 0.4 MPa.

[0031] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0032] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0033] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / TMF modified copolymer.

[0034] (5) The thermal and mechanical properties of the copolymer modified by semi-aromatic furan polyamide were tested. The results are shown in Tables 1 and 2.

[0035] Example 2

[0036] A semi-aromatic furan-based copolyamide (polybutylene furan dicarboxylate / butylene adipamide, PA4F / 46) and a preparation method thereof, characterized by comprising the following steps:

[0037] (1) 49.72 g of dimethyl furandicarboxylate, 4.38 g of adipic acid, 27.77 g of 1,4-butanediamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 122.81 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas, and then the system was pressurized to 0.4 MPa.

[0038] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0039] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0040] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / 46 modified copolymer.

[0041] (5) The thermal and mechanical properties of the PA4F-based modified copolymer were tested. The results are shown in Tables 1 and 2.

[0042] Example 3

[0043] A semi-aromatic furan-based copolyamide (polybutylene furan dicarboxylate / butylene adipamide, PA4F / 46) and a preparation method thereof, characterized by comprising the following steps:

[0044] (1) 38.67 g of dimethyl furandicarboxylate, 13.15 g of adipic acid, 27.77 g of 1,4-butanediamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 119.39 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas, and then the system was pressurized to 0.4 MPa.

[0045] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0046] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0047] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / 46 modified copolymer.

[0048] (5) The thermal and mechanical properties of the PA4F-based modified copolymer were tested. The results are shown in Tables 1 and 2.

[0049] Example 4

[0050] A semi-aromatic furan-based copolyamide (poly(butylene furan dicarboxyl) / hexamethylene furan dicarboxyl) (PA4F / 6F) and a preparation method thereof, characterized by comprising the following steps:

[0051] (1) 38.67 g of dimethyl furandicarboxylate, 19.44 g of 1,4-butanediamine, 10.98 g of 1,6-hexanediamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 103.64 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas and then pressurized to 0.4 MPa.

[0052] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0053] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0054] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / CHF modified copolymer.

[0055] (5) The thermal and mechanical properties of the PA4F-based modified copolymer were tested. The results are shown in Tables 1 and 2.

[0056] Example 5

[0057] A semi-aromatic furan-based copolyamide (poly(butylene furan dicarboxyl) / hexamethylene furan dicarboxyl) (PA4F / 6F) and a preparation method thereof, characterized by comprising the following steps:

[0058] (1) 55.24 g of dimethyl furandicarboxylate, 24.99 g of 1,4-butanediamine, 3.66 g of 1,6-hexanediamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 127.07 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas, and then the system was pressurized to 0.4 MPa.

[0059] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0060] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0061] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / 6F modified copolymer.

[0062] (5) The thermal and mechanical properties of the copolymer modified by semi-aromatic furan polyamide were tested. The results are shown in Tables 1 and 2.

[0063] Example 6

[0064] A semi-aromatic furan-based copolyamide (polybutylene furan dicarboxyl / isophthalamide PA4F / 4I) and a preparation method thereof, characterized by comprising the following steps:

[0065] (1) 55.24 g of dimethyl furandicarboxylate, 24.99 g of 1,4-butanediamine, 6.12 g of isophthalic acid, 0.92 g of [Bmim][H2PO4] ionic liquid and 127.07 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas, and then the system was pressurized to 0.4 MPa.

[0066] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0067] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0068] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not drop further for 0.5 h, the mixture was cooled and discharged to obtain the PA4F / 4I modified copolymer.

[0069] (5) The thermal and mechanical properties of the copolymer modified by semi-aromatic furan polyamide were tested. The results are shown in Tables 1 and 2.

[0070] Example 7

[0071] A semi-aromatic furan-based copolyamide (poly(butylene furan dicarboxylic acid) / (cyclohexanedimethyl furan dicarboxylic acid, PA4F / CHF) and a preparation method thereof, characterized in that the preparation method comprises the following steps:

[0072] (1) 55.24 g of dimethyl furandicarboxylate, 19.44 g of 1,4-butanediamine, 13.44 g of m-cyclohexyldimethylamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 132.19 g of deionized water were added to a 250 ml stirred autoclave. The air in the system was replaced three times with argon gas and then pressurized to 0.4 MPa.

[0073] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0074] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0075] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / CHF modified copolymer.

[0076] (5) The thermal and mechanical properties of the copolymer modified by semi-aromatic furan polyamide were tested. The results are shown in Tables 1 and 2.

[0077] Example 8

[0078] A semi-aromatic furan-based copolyamide (poly(butylene furan dicarboxylic acid) / (cyclohexanedimethyl furan dicarboxylic acid, PA4F / CHF) and a preparation method thereof, characterized in that the preparation method comprises the following steps:

[0079] (1) 55.24 g of dimethyl furandicarboxylate, 24.99 g of 1,4-butanediamine, 4.48 g of m-cyclohexyl dimethylamine, 0.92 g of [Bmim][H2PO4] ionic liquid and 127.07 g of deionized water were added to a 250 ml stirred autoclave, the air in the system was replaced three times with argon, and then the system was pressurized to 0.4 MPa.

[0080] (2) The stirring speed was adjusted to 150 rpm, and the reaction was carried out at 80°C for 1 h. The temperature was then raised to 150°C and the pressure was maintained for 3 h. The pressure was then reduced to -0.1 MPa for dehydration.

[0081] (3) Close the exhaust valve, reduce the vacuum degree to below 100 Pa, raise the temperature to 190 ° C, react for 2 hours, and adjust the mechanical stirring speed to 70 rpm.

[0082] (4) The temperature was raised to 230° C. and the reaction was carried out for 1 h, until the vacuum degree was maintained at 60 Pa, and until the vacuum degree did not further decrease for 0.5 h, the mixture was cooled and discharged to obtain a PA4F / CHF modified copolymer.

[0083] (5) The thermal and mechanical properties of the copolymer modified by semi-aromatic furan polyamide were tested. The results are shown in Tables 1 and 2.

[0084] The molecular weight of the polymer in the above examples was measured by gel permeation chromatography (GPC) using polymethyl methacrylate as a standard, and the mobile phase was hexafluoroisopropanol (containing 5 mmol / L sodium trifluoroacetate); the initial decomposition temperature and residual carbon rate were tested by TG-60H, and the glass transition temperature T g The test was conducted using a differential thermal calorimeter DSC1, and the test method was based on the literature (Journal of Polymer Science, 2014(2):233-238); the tensile test was conducted according to ASTM D638, and dumbbell-shaped specimens (25mm×4mm×2mm) were produced by injection molding. The tensile rate was 5mm / min, and at least 3 specimens were tested for each specimen.

[0085] The physical properties of the semi-aromatic furan-based copolyamides synthesized in Examples 1-8 are detailed in Tables 1 and 2.

[0086] Table 1 Physical properties of the semi-aromatic furan-based copolyamides synthesized in Examples 1-8

[0087]

[0088] Table 2 Tensile performance parameters of furan-based copolyamides synthesized in Examples 1-8

[0089] Example Elastic modulus(GPa) Tensile strength(MPa) Elongation at break (%) Example 1 2.80±0.11 88.03±0.83 6.04±0.16 Example 2 3.45±0.26 65.61±2.78 2.03±0.24 Example 3 3.42±0.34 28.32±1.92 0.85±0.10 Example 4 4.09±0.21 89.25±4.09 3.27±0.60 Example 5 3.11±0.07 90.79±2.09 5.99±0.37 Example 6 3.00±0.16 85.67±3.57 5.20±0.33 Example 7 3.32±0.09 94.26±6.99 4.09±0.62 Example 8 4.41±0.17 94.29±6.24 3.22±0.39

[0090] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Any equivalent structure or equivalent replacement made by modifying the technical solution of the present invention with reference to the embodiments, without departing from the spirit and scope of the technical solution of the present invention, are all included in the scope of protection of the present invention.

Claims

1. A semi-aromatic furan-based copolyamide and a preparation method thereof, characterized in that: Semi-aromatic furan-based copolyamides were prepared from 1,4-butanediamine (BDA), dimethyl furandicarboxylate (DMFDC) and a third comonomer via prepolymerization and direct melt polycondensation.

2. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The third comonomer is one or more of an aliphatic dibasic acid or diamine having a carbon chain length of 4 to 12 carbon atoms, aromatic isophthalic acid (IPA) or metaphenylenediamine (MPDA), a branched diamine (trimethylhexamethylenediamine) (TMD), or an alicyclic diamine (isophoronediamine (IPDA), meta-cyclohexyldimethylamine (CHDM)).

3. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The molar ratio of the 1,4-butanediamine is 10% to 90% of the molar amount of the diamine in the raw material; the molar ratio of the dimethyl furandicarboxylate is 10% to 90% of the molar amount of the diester (diacid) in the raw material.

4. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, wherein the preparation method comprises the following steps: Add the comonomer of polyamide, water and catalyst into the polymerization reactor, fill with 0.1-0.4MPa argon, react at 60-80℃ for 1-2h, heat to 130-160℃ and maintain pressure for 1-6h, slowly reduce pressure to -0.1MPa for dehydration, react at 170-190℃ for 1-3h, heat to 230-260℃ for condensation for 1-6h.

5. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The molar ratio of diester (diacid) to diamine in the monomer is 1±0.02:1±0.

05.

6. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The amount of water used as the prepolymerization medium is 100-200% of the sum of the mass of the diester (diacid) and the diamine.

7. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The polycondensation temperature in the polycondensation process is selected within a temperature range of 20-30° C., which is 1.5 times higher than the glass transition temperature of the copolyamide.

8. A semi-aromatic furan-based copolyamide and a preparation method thereof according to claim 1, characterized in that: The method to reduce the occurrence of side reactions of semi-aromatic furan-based copolyamide is to react at 60-80°C for 1-3 hours in the prepolymerization stage, and then raise the temperature to 130-190°C for 1-6 hours.

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