High-strength high-temperature-resistant antistatic PA10T composite material and preparation method thereof
By bridging CNTs and graphene with IPDI, an interpenetrating conductive network was constructed in the PA10T composite material, solving the problems of nanofiller dispersion and interfacial bonding. This resulted in improved high-efficiency antistatic properties and mechanical properties, while maintaining the material's thermal stability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- FUZHOU UNIV
- Filing Date
- 2026-03-25
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies struggle to achieve uniform dispersion and interfacial bonding of nanofillers in polymers, leading to compromised antistatic and mechanical properties. This is particularly true in PA10T materials, where it is difficult to construct a stable and efficient conductive network.
Using isophorone diisocyanate (IPDI) as a composite chain extender, carbon nanotubes (CNTs) and graphene (G) are covalently bridged. A stepwise controllable synthesis process is designed to form a structure of "first grafting CNTs, then bridging graphene", thus constructing an interpenetrating network of one-dimensional and two-dimensional nanomaterials.
The nanofiller was uniformly dispersed and strongly bonded to the PA10T matrix, which significantly improved the antistatic and mechanical properties of the material, reduced the percolation threshold, and improved the thermal stability and electrical conductivity of the material.
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Figure CN122011376A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of polymer composite materials technology, specifically to a high-performance semi-aromatic polyamide composite material. More specifically, this invention relates to a poly(terephthalamide) decylamine (PA10T) composite material and its preparation method, which simultaneously achieves high molecular weight and efficient antistatic function by introducing a composite chain extender based on isophorone diisocyanate (IPDI) bridging carbon nanotubes (CNTs) and graphene (G). Background Technology
[0002] Poly(decyl terephthalamide) (PA10T) is a high-performance semi-aromatic high-temperature resistant polyamide. Its monomer, decanediamine, is derived from castor oil, a renewable resource, making it environmentally friendly. The PA10T molecular chain contains both rigid benzene rings and flexible methylene segments, giving it advantages such as a high melting point (approximately 316°C), excellent heat resistance, good dimensional stability, low water absorption, and resistance to chemical solvents. It has broad application prospects in the electronics, automotive, and aerospace industries.
[0003] To impart antistatic properties to PA10T, a conventional method is to directly blend conductive fillers, such as carbon black, carbon nanotubes (CNTs), or graphene. However, these nanofillers, due to their extremely high specific surface area and strong van der Waals forces, are prone to agglomeration in the polymer melt, leading to uneven dispersion. This not only results in a high filler addition amount required to achieve the ideal conductivity threshold but also severely impairs the material's mechanical properties, especially impact toughness. Furthermore, physically blended fillers have weak interfacial bonding with the polymer matrix, making them prone to interfacial debonding during use, leading to unstable performance. On the other hand, using chain extenders in polyamide synthesis or processing is an effective means to increase its molecular weight, improve processing performance, and enhance the mechanical properties of the final product. Isophorone diisocyanate (IPDI) is an alicyclic diisocyanate containing two isocyanate (-NCO) groups with different reactivity, a characteristic that gives it a unique advantage in controlled polymer modification.
[0004] In existing technologies, research combining conductive fillers and chain extenders largely focuses on using a single type of diisocyanate (such as MDI) or simple pretreatment of the filler. However, it is often difficult to simultaneously optimize filler dispersion, interfacial bonding, chain extension efficiency, and the overall performance of the final composite material. In particular, how to precisely control the directional bridging of chain extender molecules between two different dimensional nanomaterials (such as one-dimensional CNTs and two-dimensional graphene) to construct a stable and efficient synergistic conductive network remains a technical challenge. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an antistatic PA10T composite material with excellent comprehensive performance. Another objective of this invention is to provide a composite chain extender with an innovative structure for preparing this material and its controllable synthesis method. This composite chain extender can simultaneously solve the dispersion and interface problems of nanofillers, and achieve efficient integration of chain extension enhancement and antistatic function within the PA10T matrix.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, comprising the following steps: (1) 1,10-diaminodecane, terephthalic acid, sodium hypophosphite catalyst and antioxidant 1010 were ultrasonically dispersed in deionized water; (2) The dispersion obtained in step (1) was transferred to a high-temperature and high-pressure reactor and stirred for 2 hours under a nitrogen atmosphere at 80°C and 0.1 MPa to obtain PA10T salt; (3) Under the condition of stirring, the temperature was raised to 240°C and the pressure was maintained at 2.0~3.0 MPa for 4 hours. (4) Add the composite chain extender IPDI-CNT-G into the reactor and continue the reaction at 240°C and 2.5MPa for 2 hours; (5) Depressurize and cool the reactor, place its prepolymer in a glass petri dish, put it in a high-temperature vacuum drying oven, solid phase thickening for 4 hours, and then cool naturally to room temperature to obtain the high-strength, high-temperature resistant, and antistatic PA10T composite material.
[0007] Furthermore, in steps (1) and (4) above, the raw materials used include, by weight, 52 parts of 1,10-diaminodecane, 50 parts of terephthalic acid, 2-6 parts of the composite chain extender IPDI-CNT-G, 0.1 parts of the catalyst sodium hypophosphite, and 1 part of the antioxidant 1010.
[0008] Furthermore, in step (4) above, the composite chain extender is a complex formed by isophorone diisocyanate (IPDI) molecules bridging carboxylated carbon nanotubes (COOH-CNT) and amino-functionalized graphene (NH2-G) through covalent bonds; wherein, the highly reactive isocyanate groups in the IPDI molecule form amide bonds with the carboxyl groups of COOH-CNT, and the remaining low-reactivity isocyanate groups in the IPDI molecule form urea bonds with the amino groups of NH2-G.
[0009] Furthermore, the preparation method of the composite chain extender IPDI-CNT-G in step (4) above adopts a "stepwise controllable grafting" synthesis process, including the following steps: (1) MWCNTs were placed in a concentrated H2SO4 / HNO3 (volume ratio 3:1) mixed acid and sonicated at 60°C for 4 hours. This process introduces carboxyl groups (-COOH) onto the CNT surface. After the reaction, the CNTs were washed with deionized water until neutral, filtered, and vacuum dried at 80°C to constant weight to obtain carboxylated carbon nanotubes (COOH-CNTs). GO was dispersed in deionized water, excess p-phenylenediamine was added as an amine source, and an appropriate amount of hydrazine hydrate was added. The mixture was refluxed at 95°C for 24 hours. This process simultaneously achieves the chemical reduction and surface amination of graphene oxide, generating amino-functionalized graphene. After the reaction, the graphene was filtered, washed, and dried to obtain amino-functionalized graphene (NH2-G).
[0010] (2) First-step grafting: 1.0 g of dried COOH-CNT was dispersed in 150 mL of anhydrous DMF and sonicated for 1 hour to ensure complete dispersion. The system was placed in an ice-water bath, and IPDI was added in a stoichiometric ratio while stirring. The amount of IPDI added should ensure that the molar ratio of its total -NCO groups to the -COOH on the CNT surface is 1.5:1 to ensure that some -NCO remains. Two drops of DBTDL catalyst were added. The system was then slowly heated to 60 °C and reacted at this temperature for 6 hours. This temperature is intended to preferentially promote the reaction of highly active -NCO and -COOH on IPDI, while retaining as much low-activity -NCO as possible. After the reaction was completed, a DMF dispersion of IPDI-g-CNT was obtained.
[0011] (3) Second step bridging: Disperse 0.5 g of the NH2-G prepared in step (1) in 50 mL of anhydrous DMF and sonicate for 30 minutes. Add the NH2-G dispersion dropwise to the above IPDI-g-CNT reaction system. Maintain the reaction temperature at 60°C and continue stirring for 24 hours. This mild condition is conducive to the reaction of the remaining -NCO and -NH2 to form urea bonds, while avoiding the thermal degradation of the grafted structure. During the reaction, intermittent mild sonication (5 minutes every 3 hours) can be used to promote the dispersion and interfacial contact of NH2-G.
[0012] (4) Slowly pour the reacted mixture into a large amount (about 10 times its volume) of stirred methanol. Due to the extremely low solubility of the complex in methanol, a black precipitate will form. Collect the precipitate by filtration. Wash the filter cake repeatedly with fresh methanol 3-4 times to remove excess impurities from the surface. Place the filter cake in a vacuum drying oven and dry it at 80°C for 48 hours until constant weight is achieved. The final product is a black, fluffy powder, which is the target composite chain extender IPDI-CNT-G.
[0013] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an antistatic PA10T composite material with excellent comprehensive performance. Another objective of this invention is to provide a composite chain extender with an innovative structure for preparing this material and its controllable synthesis method. This composite chain extender can simultaneously solve the dispersion and interface problems of nanofillers, and achieve efficient integration of chain extension enhancement and antistatic function within the PA10T matrix.
[0014] The beneficial effects of this invention are as follows: (1) Innovative composite chain extender structure: By creatively utilizing the inherent activity difference between the two -NCO groups of IPDI, a stepwise controllable synthesis route of "first attaching CNTs, then bridging graphene" was designed, realizing the directional and covalent connection of the two nanomaterials at the molecular scale. The structure is clear and highly controllable. The CNT-IPDI-G composite structure was constructed, realizing the controllability of the grafting process.
[0015] (2) Significant synergistic effect: The conductive network is efficiently constructed. Through IPDI chemical bridging, CNT and graphene can form a stable and interpenetrating "one-dimensional + two-dimensional" three-dimensional hybrid conductive network in the PA10T matrix, which significantly reduces the percolation threshold and achieves excellent antistatic performance with a low addition amount.
[0016] (3) Comprehensive improvement in mechanical properties: The chain extension effect of IPDI effectively increases the molecular weight of PA10T. In the first grafting step, IPDI is added in excess, and the reaction is stepwise and controllable. Therefore, the final product inevitably contains some unreacted, free, or -NCO groups located at the end of the "bridge". From the infrared spectrum at -2275 cm⁻¹ -1 This is the characteristic stretching vibration peak of its isocyanate group (-NCO), indicating that -NCO groups still exist in the powder, laying the foundation for subsequent chain extension function. At the same time, the -NCO group located at the end of the "bridge" can be firmly anchored to CNTs and graphene in the polymer matrix in the form of covalent bonds. As a nano-reinforcement, it can simultaneously transfer stress and hinder crack propagation, thereby synergistically improving the tensile strength of the material.
[0017] (4) Excellent interfacial compatibility and thermal stability: The alicyclic structure of IPDI endows the composite chain extender with better thermal stability and high-temperature resistance. Covalent bonding ensures uniform dispersion and strong interfacial bonding of CNTs and graphene in the polymer matrix, which can synergistically construct a highly efficient three-dimensional conductive network. At the same time, the active groups of free IPDI can provide sites for subsequent polyamide chain extension reactions, improving the overall thermal stability of the composite material. Furthermore, this composite chain extender is suitable for both in-situ synthesis of PA10T and reactive blending in post-processing, providing convenience for flexible design of material properties and industrial production. Attached Figure Description
[0018] Figure 1 FTIR images of unmodified carbon nanotubes (MWCNTs) and the prepared IPDI-CNT-G as antistatic fillers.
[0019] Figure 2 To plot TG using thermogravimetric analysis (TGA) data.
[0020] Figure 3 SEM image of IPDI-CNT-G composite chain extender powder.
[0021] Figure 4 This is a SEM image of the cross-section of the high-strength, high-temperature resistant, and antistatic PA10T composite material prepared in Example 1. Detailed Implementation
[0022] The preparation method of the composite chain extender IPDI-CNT-G adopts a "stepwise controllable grafting" synthesis process, including the following steps: (1) MWCNTs were placed in a concentrated H2SO4 / HNO3 (volume ratio 3:1) mixed acid and sonicated at 60°C for 4 hours. This process introduces carboxyl groups (-COOH) onto the CNT surface. After the reaction, the CNTs were washed with deionized water until neutral, filtered, and vacuum dried at 80°C to constant weight to obtain carboxylated carbon nanotubes (COOH-CNTs). GO was dispersed in deionized water, and excess p-phenylenediamine was added as an amine source, along with an appropriate amount of hydrazine hydrate. The mixture was refluxed at 95°C for 24 hours. This process simultaneously achieves the chemical reduction and surface amination of graphene oxide, generating amino-functionalized graphene. After the reaction, the graphene was filtered, washed, and dried to obtain amino-functionalized graphene (NH2-G).
[0023] (2) First-step grafting: 1.0 g of dried COOH-CNT was dispersed in 150 mL of anhydrous DMF and sonicated for 1 hour to ensure complete dispersion. The system was placed in an ice-water bath, and IPDI was added in a stoichiometric ratio while stirring. The amount of IPDI added should ensure that the molar ratio of its total -NCO groups to the -COOH on the CNT surface is 1.5:1 to ensure that some -NCO remains. Two drops of DBTDL catalyst were added. The system was then slowly heated to 60 °C and reacted at this temperature for 6 hours. This temperature is intended to preferentially promote the reaction of highly active -NCO and -COOH on IPDI, while retaining as much low-activity -NCO as possible. After the reaction was completed, a DMF dispersion of IPDI-g-CNT was obtained.
[0024] (3) Second step bridging: Disperse 0.5 g of the NH2-G prepared in step (1) in 50 mL of anhydrous DMF and sonicate for 30 minutes. Add the NH2-G dispersion dropwise to the above IPDI-g-CNT reaction system. Maintain the reaction temperature at 60°C and continue stirring for 24 hours. This mild condition is conducive to the reaction of the remaining -NCO and -NH2 to form urea bonds, while avoiding the thermal degradation of the grafted structure. During the reaction, intermittent mild sonication (5 minutes every 3 hours) can be used to promote the dispersion and interfacial contact of NH2-G.
[0025] (4) Slowly pour the reacted mixture into a large amount (about 10 times its volume) of stirred methanol. Due to the extremely low solubility of the complex in methanol, a black precipitate will form. Collect the precipitate by filtration. Wash the filter cake repeatedly with fresh methanol 3-4 times to remove excess impurities from the surface. Place the filter cake in a vacuum drying oven and dry it at 80°C for 48 hours until constant weight is achieved. The final product is a black, fluffy powder, which is the target composite chain extender IPDI-CNT-G.
[0026] A high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, comprising the following steps: (1) 1,10-diaminodecane, terephthalic acid, sodium hypophosphite catalyst and antioxidant 1010 were ultrasonically dispersed in deionized water; (2) The dispersion obtained in step (1) was transferred to a high-temperature and high-pressure reactor and stirred for 2 hours under a nitrogen atmosphere at 80°C and 0.1 MPa to obtain PA10T salt; (3) Under the condition of stirring, the temperature was raised to 240°C and the pressure was maintained at 2.0~3.0 MPa for 4 hours. (4) Add the composite chain extender IPDI-CNT-G into the reactor and continue the reaction at 240°C and 2.5MPa for 2 hours; (5) Depressurize and cool the reactor, place its prepolymer in a glass petri dish, put it in a high-temperature vacuum drying oven, solid phase thickening for 4 hours, and then cool naturally to room temperature to obtain the high-strength, high-temperature resistant, and antistatic PA10T composite material.
[0027] Furthermore, in steps (1) and (4) above, the raw materials used include, by weight, 52 parts of 1,10-diaminodecane, 50 parts of terephthalic acid, 2-6 parts of the composite chain extender IPDI-CNT-G, 0.1 parts of the catalyst sodium hypophosphite, and 1 part of the antioxidant 1010.
[0028] To make the content of this invention easier to understand, the technical solution of this invention will be further described below with reference to specific embodiments, but this invention is not limited thereto.
[0029] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.
[0030] The raw materials used in the examples are as follows: 1,10-diaminodecane (97% purity), terephthalic acid (99% purity), sodium hypophosphite catalyst (99% purity), antioxidant 1010 (99% purity), isophorone diisocyanate (IPDI, 99% purity), multi-walled carbon nanotubes (MWCNTs, 95% purity, diameter 10-20 nm, length 10-30 μm), graphene oxide (GO, 98% purity), concentrated sulfuric acid (98% purity), concentrated nitric acid (68% purity), N,N-dimethylformamide (AR), and dibutyltin dilaurate (AR). Before the synthesis experiment, the powders of each component were placed in a vacuum drying oven at 60°C and 0 MPa for 12 hours to remove the influence of moisture. Example 1
[0031] The preparation method of the composite chain extender IPDI-CNT-G adopts a "stepwise controllable grafting" synthesis process, including the following steps: (1) 1.5 g of MWCNTs were placed in 200 mL of concentrated H2SO4 / HNO3 (volume ratio 3:1) mixed acid and sonicated at 60°C for 4 hours. This process introduces carboxyl groups (-COOH) onto the CNT surface. After the reaction, the CNTs were washed with deionized water until neutral, filtered, and vacuum dried at 80°C to constant weight to obtain carboxylated carbon nanotubes (COOH-CNTs). 1.0 g of GO was dispersed in 150 mL of deionized water, 0.5 g of p-phenylenediamine was added as an amine source, and 1.0 mL of hydrazine hydrate was added. The mixture was refluxed at 95°C for 24 hours. This process simultaneously achieves the chemical reduction and surface amination of graphene oxide to generate amino-functionalized graphene. After the reaction, the graphene was filtered, washed, and dried to obtain amino-functionalized graphene (NH2-G).
[0032] (2) First-step grafting: Under a nitrogen atmosphere, 1.0 g of dry COOH-CNT was dispersed in 150 mL of anhydrous DMF and sonicated for 1 hour to ensure complete dispersion. The system was placed in an ice-water bath, and IPDI was added in a stoichiometric ratio with stirring. The amount of IPDI added should ensure that the molar ratio of its total -NCO groups to the -COOH on the CNT surface is 1.5:1 to ensure that some -NCO remains. Two drops of DBTDL catalyst were added. The system was then slowly heated to 60 °C and reacted at this temperature for 6 hours. This temperature is intended to preferentially promote the reaction of highly active -NCO and -COOH on IPDI, while retaining as much low-activity -NCO as possible. After the reaction was completed, a DMF dispersion of IPDI-g-CNT was obtained.
[0033] (3) Second step bridging: Disperse 0.5 g of the NH2-G prepared in step (1) in 50 mL of anhydrous DMF and sonicate for 30 minutes. Add the NH2-G dispersion dropwise to the above IPDI-g-CNT reaction system. Maintain the reaction temperature at 60°C and continue stirring for 24 hours. This mild condition is conducive to the reaction of the remaining -NCO and -NH2 to form urea bonds, while avoiding the thermal degradation of the grafted structure. During the reaction, intermittent mild sonication (5 minutes every 3 hours) can be used to promote the dispersion and interfacial contact of NH2-G.
[0034] (4) Slowly pour the reacted mixture into a large amount (about 10 times its volume) of stirred methanol. Due to the extremely low solubility of the complex in methanol, a black precipitate will form. Collect the precipitate by filtration. Wash the filter cake repeatedly with fresh methanol 3-4 times to remove excess impurities from the surface. Place the filter cake in a vacuum drying oven and dry it at 80°C for 48 hours until constant weight is achieved. The final product is a black, fluffy powder, which is the target composite chain extender IPDI-CNT-G.
[0035] A high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, comprising the following steps: (1) Disperse 52 parts of 1,10-diaminodecane (DMD), 50 parts of terephthalic acid (PTA), 0.1 parts of sodium hypophosphite catalyst and 1 part of antioxidant 1010 in 50 mL of deionized water by ultrasonication. (2) The dispersion obtained in step (1) was transferred to a high-temperature and high-pressure reactor and stirred for 2 hours under a nitrogen atmosphere at 80°C and 0.1 MPa to obtain PA10T salt; (3) Under the condition of stirring, the temperature was raised to 240°C and the pressure was maintained at 2.5 MPa for 4 hours. (4) Add 4 parts of the composite chain extender IPDI-CNT-G into the reactor and continue the reaction at 240℃ and 2.5MPa for 2 hours; (5) Depressurize and cool the reactor, place its prepolymer in a glass petri dish, put it in a high-temperature vacuum drying oven, and solidify it for 4 hours under the experimental conditions of vacuuming to -0.09MPa (gauge pressure), 260℃, and 15Pa. Then, let it cool naturally to room temperature to obtain a high-strength, high-temperature resistant, and antistatic PA10T composite material.
[0036] Figure 1 The image shows the FTIR spectra of unmodified multi-walled carbon nanotubes (MWCNTs) and the prepared IPDI-CNT-G. The original MWCNTs are shown at -3420 cm⁻¹. -1The absorption peak is broad and strong, attributed to the OH stretching vibration, at -2923 cm⁻¹. -1 The peak is relatively weak, corresponding to the asymmetric and symmetric stretching vibrations of aliphatic CH bonds, while the peak is at -1630 cm⁻¹. -1 There is a significant absorption peak at this point, which is sp. 2 The stretching vibration characteristic peak of the hybrid carbon skeleton (C=C) is the intrinsic structural signal of CNTs. After the preparation of the IPDI-CNT-G composite chain extender, a series of decisive changes occur in the spectrum, proving that the -NCO group of IPDI is covalently bonded to the -COOH group of CNTs and the -NH2 group of graphene. At -3345 cm⁻¹ -1 There is a characteristic peak at -2275 cm⁻¹, attributed to the stretching vibration of the newly formed secondary amine (-NH⁻). -1 This is the characteristic stretching vibration peak of its isocyanate group (-NCO), indicating that -NCO groups still exist in the powder, laying the foundation for subsequent chain extension function. At -1656 cm⁻¹ -1 A new strong absorption peak will appear or the original peak shape will change significantly. This corresponds to the C=O stretching vibration in the amide bond (-CONH-, from the reaction of IPDI with CNT-COOH) and urea bond (-NHCONH-, from the reaction of IPDI with graphene-NH2) formed in the reaction. -1564cm -1 A new characteristic peak appears, mainly attributed to the in-plane bending vibration of the NH bond and the stretching vibration of the CN bond, providing further conclusive evidence of amide / urea bond formation. This confirms the successful implementation of the designed "stepwise covalent bridging mechanism based on the activity difference of IPDI-NCO," whereby one end of the IPDI molecule forms an amide bond with the carboxyl group of CNT, and the other end forms a urea bond with the amino group of graphene, thus constructing a well-defined composite chain extender that simultaneously functions as both a chain extender and a reinforcing agent.
[0037] Figure 2 Thermogravimetric analysis (TGA) was used to perform TG plot analysis on the data of Examples 1, 2, 3 and Comparative Example 1. It can be clearly observed that the thermal decomposition temperature of PA10T modified with composite chain extender is slightly higher than that of Comparative Example 1, but both are above 410℃, maintaining the inherent high temperature resistance of PA10T material.
[0038] Figure 3 This is a SEM image of the composite chain extender IPDI-CNT-G powder. It can be seen that the carbon nanotubes have morphology and some graphene particles on the surface, indicating good particle dispersion.
[0039] Figure 4This is a SEM image of the cross-section of the high-strength, high-temperature resistant, and antistatic PA10T composite material prepared in Example 1. The carbon nanotubes in the composite chain extender IPDI-CNT-G form a highly efficient three-dimensional conductive network within the PA10T matrix, promoting conductivity and further enhancing antistatic properties. Example 2
[0040] The difference is that in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, 2 parts of the composite chain extender IPDI-CNT-G are added to the reactor, and the other operations are the same as in Example 1. Example 3
[0041] The difference is that in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, 6 parts of the composite chain extender IPDI-CNT-G are added to the reactor, and other operations are the same as in Example 1.
[0042] Comparative Example 1
[0043] The difference is that no composite chain extender is added in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method. Other operations are the same as in Example 1, and pure PA10T polymer is obtained.
[0044] Comparative Example 2
[0045] The difference is that in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, 4 parts of pure isophorone diisocyanate (IPDI) are used as chain extenders, and other operations are the same as in Example 1.
[0046] Comparative Example 3
[0047] The difference is that in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, only 4 parts of multi-walled carbon nanotubes (MWCNTs) are added, and the other operations are the same as in Example 1.
[0048] Comparative Example 4
[0049] The difference is that in step (4) of the high-strength, high-temperature resistant, and antistatic PA10T composite material and its preparation method, only 4 parts of graphene oxide (GO) are added, while other operations are the same as in Example 1.
[0050] Density is measured by ρ = m / ΔV, where ΔV is the volume change obtained by immersing the sample in a graduated cylinder. The water absorption rate test shall be conducted in accordance with GB / T1034-2008 Determination of Water Absorption of Plastics; Tensile strength testing shall be performed in accordance with GB / T 1040.2-2022 Determination of Tensile Properties of Plastics; The elongation at break test shall be performed in accordance with GB / T 1040-1-2018 Determination of tensile properties of plastics; The impact strength test shall be conducted in accordance with GB / T 1843-2008 Determination of Impact Strength of Cantilever Beams; The antistatic performance test utilizes volume resistivity and employs a high-resistivity meter, with the test conforming to GB / T 1410-2006.
[0051] Thermogravimetric analysis (TGA) characterizes the thermal stability of materials by recording the mass changes of samples at different temperatures to analyze parameters such as decomposition temperature and rate of thermal weight loss. A simultaneous thermogravimetric analyzer (STA449-F5, NETZSCH) was used to perform TGA on different sample materials. 5-10 mg of sample was weighed and placed in an alumina crucible. Under a nitrogen atmosphere, the heating rate was set to 20 °C / min, and the test temperature range was 35 °C - 800 °C. The 5% weight loss temperature (Td, 5%) was recorded.
[0052] Table 1. Performance test results of high-strength, high-temperature resistant, and antistatic PA10T composite material samples
[0053] Table 1 shows that, taking Example 1 as an example, the composite material prepared in this invention exhibits excellent performance balance. The tensile strength reaches 135.2 MPa, an improvement of 52.6% compared to pure PA10T; simultaneously, the impact strength is as high as 14.8 kJ / m². 2 This represents a 45.1% increase, and the volume resistivity has decreased to 6.3 × 10⁻⁶. 7 Ω·cm, achieving a durable antistatic level (<10) 9The thermal decomposition temperature (426℃) is not much different from that of pure PA10T, maintaining the inherent high-temperature resistance of the material. Comparative Example 2, using pure isophorone diisocyanate (IPDI), showed a slight improvement in tensile strength and impact strength, but the volume resistivity remained relatively high. Comparative Examples 3 and 4 both added a single filler, which improved the antistatic effect to some extent, but the mechanical properties did not change much. Overall, the effects were not as good as those of Example 1. This is because CNTs and graphene can form a stable and interpenetrating "one-dimensional + two-dimensional" three-dimensional hybrid conductive network in the PA10T matrix, significantly reducing the percolation threshold and achieving excellent antistatic performance with a low addition amount. Moreover, it was confirmed that the IPDI-CNT-G hybrid network constructed by IPDI bridging has extremely high conductivity. In terms of mechanical properties, the indicators of the materials in the examples are all better than those of pure resin and the comparative examples with a single filler, achieving a synergistic effect of "reinforcement and toughening", proving the dual success of the composite chain extender in improving the interface and chain extension. The alicyclic structure of IPDI endows the composite chain extender with better thermal stability and high-temperature resistance. Covalent bonding ensures uniform dispersion and strong interfacial bonding of CNTs and graphene in the polymer matrix, enabling the synergistic construction of a highly efficient three-dimensional conductive network. At the same time, the active groups at the ends of IPDI can provide sites for subsequent polyamide chain extension reactions, improving the overall thermal stability of the composite material.
[0054] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be included in the scope of the present invention.
Claims
1. A method for preparing a high-strength, high-temperature resistant, and antistatic PA10T composite material, characterized in that, Includes the following steps: (1) 1,10-diaminodecane, terephthalic acid, sodium hypophosphite catalyst and antioxidant 1010 were ultrasonically dispersed in deionized water; (2) The dispersion obtained in step (1) was transferred to a high-temperature and high-pressure reactor and stirred for 2 hours under a nitrogen atmosphere at 80°C and 0.1 MPa to obtain PA10T salt; (3) Under the condition of stirring, the temperature was raised to 240°C and the pressure was maintained at 2.0~3.0 MPa for 4 hours. (4) Add the composite chain extender IPDI-CNT-G into the reactor and continue the reaction at 240°C and 2.5MPa for 2 hours; (5) Depressurize and cool the reactor, place its prepolymer in a glass petri dish, put it in a high-temperature vacuum drying oven, solid phase thickening for 4 hours, and then cool naturally to room temperature to obtain the high-strength, high-temperature resistant, and antistatic PA10T composite material.
2. The preparation method according to claim 1, characterized in that, The raw materials used, by weight, include: 52 parts of 1,10-diaminodecane, 50 parts of terephthalic acid, 2-6 parts of the composite chain extender IPDI-CNT-G, 0.1 parts of the catalyst sodium hypophosphite, and 1 part of the antioxidant 1010.
3. The preparation method according to claim 1, characterized in that, The composite chain extender IPDI-CNT-G is a complex formed by isophorone diisocyanate IPDI molecules bridging carboxylated carbon nanotubes COOH-CNT and amino-functionalized graphene NH2-G via covalent bonds; wherein, the highly reactive isocyanate groups in the IPDI molecule form amide bonds with the carboxyl groups of COOH-CNT, and the remaining low-reactivity isocyanate groups in the IPDI molecule form urea bonds with the amino groups of NH2-G.
4. The preparation method according to claim 3, characterized in that, The composite chain extender IPDI-CNT-G is synthesized using a "stepwise controlled grafting" process, which specifically includes the following steps: 1) Carbon nanotubes were acid-oxidized to obtain carboxylated carbon nanotubes COOH-CNT with carboxyl groups on the surface; then graphene oxide was chemically reduced and amination-treated to obtain amino-functionalized graphene NH2-G. 2) First step of grafting: COOH-CNT is dispersed in anhydrous polar solvent and reacted with a measured amount of IPDI at 40-60℃ for 4-8 hours in the presence of protective gas and catalyst. The total amount of IPDI is controlled so that the molar ratio of -NCO groups to -COOH on the CNT surface is 1.5:
1. This step aims to utilize the highly active -NCO of IPDI to react with -COOH to generate IPDI-g-CNT intermediate while retaining the less active -NCO. 3) Second step bridging: Without separating the intermediate, the dispersion of NH2-G is added to the above IPDI-g-CNT reaction system, and the reaction is continued at 60°C for 24 hours to allow the low-activity -NCO remaining on IPDI-g-CNT to fully react with the -NH2 of NH2-G. This process uses intermittent ultrasonic-assisted dispersion. 4) After the reaction is complete, the mixture is poured into methanol to settle. After filtration, washing, and vacuum drying at 80°C for 48 hours, a black powdery composite chain extender IPDI-CNT-G is obtained.
5. The preparation method according to claim 4, characterized in that, In step 2), the catalyst used is dibutyltin dilaurate, the anhydrous polar solvent is anhydrous N,N-dimethylformamide, and the protective gas is nitrogen.
6. The preparation method according to claim 4, characterized in that, In step 3), the intermittent ultrasonic-assisted dispersion specifically involves ultrasonication for 5 minutes every 3 hours during the reaction period to ensure that the powder is fully dispersed and reacted.
7. The high-strength, high-temperature resistant, and antistatic PA10T composite material prepared by the preparation method according to any one of claims 1-6.