Composite material comprising thermoplastic polyurethane and graphene oxide, use thereof, and manufacturing method therefor

Abstract

The present invention provides a composite material comprising thermoplastic polyurethane and graphene oxide, and a use thereof for manufacturing cables. By adding graphene oxide into thermoplastic polyurethane, the composite material achieves both excellent mechanical properties and heat dissipation performance, and cables manufactured therefrom have good safety and long service life.

Description

Composite materials containing thermoplastic polyurethane and graphene oxide, their applications and manufacturing methods Technical Field

[0001] This invention relates to composite materials, particularly composite materials comprising thermoplastic polyurethane (TPU) and graphene oxide. Background Technology

[0002] Thermoplastic polyurethane (TPU) is known for its excellent transparency, abrasion resistance, aging resistance, and oil resistance. It also performs well in terms of load-bearing capacity and tensile strength. It is a multifunctional material that can be manufactured by methods such as injection molding, extrusion molding, and blow molding. It is widely used in products such as sports shoes, raincoats, automotive hoses, protective gloves, and cables.

[0003] TPU plays a crucial role in cable manufacturing, especially in cable sheath applications where a balance needs to be struck between tensile strength, flame retardancy, and thermal deformation. Furthermore, because the passage of current through a cable generates high temperatures, its heat dissipation performance is critical for extending its service life. Good heat dissipation helps prevent overheating and thermal damage, ensuring safe operation and allowing the cable to carry higher currents, thus enabling a reduction in wire diameter for greater flexibility. Therefore, achieving the optimal balance between mechanical properties and heat dissipation is a significant challenge in cable-related fields. Summary of the Invention

[0004] This invention provides a composite material and its use in manufacturing cables. By adding graphene oxide to thermoplastic polyurethane, it achieves the advantages of both excellent mechanical properties and heat dissipation. Cables made from this composite material have good safety, heat dissipation, flexibility, and long service life.

[0005] To achieve the above objectives, the present invention provides a composite material comprising thermoplastic polyurethane and graphene oxide, wherein the weight ratio of thermoplastic polyurethane to graphene oxide is 9:1 to 7:3.

[0006] In a composite material according to one embodiment of the present invention, the weight ratio of thermoplastic polyurethane to graphene oxide is 4:1.

[0007] In a composite material according to one embodiment of the present invention, graphene oxide is modified with amino groups.

[0008] In a composite material according to one embodiment of the present invention, the weight-average molecular weight of the thermoplastic polyurethane can be 130,000.

[0009] In one embodiment of the composite material of the present invention, the tensile strength measured according to ASTM D638 is greater than or equal to 10 megapascals (MPa).

[0010] In a composite material according to one embodiment of the present invention, the elongation measured according to ASTM D638 is greater than or equal to 300%.

[0011] In one embodiment of the composite material of the present invention, the withstanding voltage measured according to ASTM D149 is greater than or equal to 2.0 kV.

[0012] In a composite material according to one embodiment of the present invention, the leakage current measured according to ASTM D149 is less than 0.5 mA.

[0013] On the other hand, the present invention also provides the use of a composite material comprising thermoplastic polyurethane and graphene oxide for manufacturing cables.

[0014] On the other hand, the present invention also provides a method for manufacturing a heat dissipation composite material for cables, comprising: modifying graphene oxide using an aminosilane coupling agent, and then mixing thermoplastic polyurethane and modified graphene oxide in a weight ratio of 9:1 to 7:3 using a twin-screw extruder to produce a heat dissipation composite material for cables.

[0015] The effects of the present invention are not limited to those mentioned above, and those skilled in the art to which this invention pertains will clearly understand from the following description the effects not mentioned above. Detailed Implementation

[0016] The following embodiments describe in detail the features and advantages of the present invention, the content of which is sufficient to enable anyone skilled in the art to understand the technical content of the present invention and implement it accordingly. Based on the disclosure, patent claims, and drawings in this specification, anyone skilled in the art can easily understand the relevant objectives and advantages of the present invention. The following embodiments are intended to further illustrate the points of the present invention, but are not intended to limit the scope of the present invention in any way.

[0017] The present invention provides a composite material comprising thermoplastic polyurethane (TPU) and graphene oxide, wherein the weight ratio of thermoplastic polyurethane to graphene oxide is 9:1 to 7:3.

[0018] In a composite material according to one embodiment of the present invention, the weight ratio of thermoplastic polyurethane to graphene oxide is 4:1.

[0019] In one embodiment of the composite material of the present invention, the thermoplastic polyurethane used in the present invention has a weight average molecular weight of 130,000, and the graphene oxide used in the present invention is amino-modified graphene oxide, type O-PG, with a particle size of 2-3 nm and an oxygen content ≥40% by weight (wt%). Amino-modified graphene oxide improves its dispersibility, adhesion, and compatibility in thermoplastic polyurethane.

[0020] The preparation, testing, and test results of composite materials according to several embodiments of the present invention are described below.

[0021] Preparation method: Graphene oxide was modified with an aminosilane coupling agent. Then, the modified graphene oxide and TPU were mixed in different ratios (as shown in Table 1) using a twin-screw extruder to form a composite material. Samples were then made by injection molding or extrusion molding.

[0022] The property testing method is as follows:

[0023] 1. Tensile strength, elongation, and Young's modulus: These were determined according to ASTM D638 TYPE IV. Following this procedure, a dog-bone shaped sample with a total length of 165 mm, a thickness of 3.2 mm (1 / 8 inch), and a gauge length of 50 mm (2 inches) was fixed between two clamps at room temperature. The sample was stretched at a rate of 50 mm / min until fracture, and the tensile strength and elongation were recorded. The Young's modulus was calculated from the tensile force and the amount of deformation of the sample.

[0024] 2. Hardness: A dog bone-shaped sample measuring 2 inches x 2 inches and with a minimum thickness of 6.4 mm (0.25 inches) was used to determine the hardness using a Shore D hardness tester according to ASTM D2240.

[0025] 3. Surface resistivity: Measured according to ASTM D257. Following this procedure, a 10cm × 10cm × 2mm sample is connected to two electrodes, a voltage is applied, and the current flowing through the sample is recorded. The surface resistivity is calculated from the measured voltage and current.

[0026] 4. Withstand Voltage Test: The test is performed according to ASTM D149. Following this procedure, a 10cm × 10cm × 2mm sample is connected to two electrodes. Leakage current is recorded at different voltages, and a voltage is applied until dielectric breakdown occurs. The voltage at the point of breakdown is recorded (i.e., withstand voltage).

[0027] 5. Thermal conductivity: Determined according to ISO 22007-2 (Instantaneous Plane Heat Source (Hot Plate) Method). According to this procedure, a disc-shaped heat source is placed in the center of a 10cm × 10cm × 3mm sample, and the heat source is heated. The thermal conductivity of the sample is calculated by measuring the temperature change of the hot plate over time.

[0028] 6. Cooling efficiency: A 10cm×10cm×4mm sample was heated for 900 seconds using a 0.36W heater, and the sample temperature was recorded. The cooling efficiency of each sample was calculated using Equation 1 based on the measured temperature. Equation 1: Cooling efficiency = (Example temperature - Comparative example temperature) / Comparative example temperature × 100%.

[0029] In addition, the composite material of the present invention was further subjected to aging, oil resistance, hydrolysis resistance, acid resistance, alkali resistance, low-temperature elongation, and tear resistance tests. The following describes each treatment and test.

[0030] Aging resistance test: According to ASTM D412, the sample is placed in an oven at 110°C and subjected to a constant temperature of 110°C with air exchange 8 to 20 times. After 168 hours, the physical properties of the sample are tested.

[0031] Oil resistance test: According to ASTM D412, the sample is placed in the test oil and placed in an oven at 110°C. The sample is subjected to a constant temperature of 110°C and air exchanged 8 to 20 times. After 168 hours, the physical properties of the sample are tested.

[0032] Hydrolysis resistance test: According to IEC 62893-2, the sample is placed in circulating water at 80°C, and after being kept at a constant temperature of 80°C with air exchange 8 to 20 times, the physical properties of the sample are tested after 168 hours.

[0033] Acid resistance test: According to IEC 60811-404, the sample was placed in an oxalic acid aqueous solution at 23°C for 5 hours and the sample properties were tested.

[0034] Alkali resistance test: According to IEC 60811-404, the sample was placed in a sodium hydroxide aqueous solution at 23°C for 5 hours and the sample properties were tested.

[0035] Low-temperature elongation test: According to the IEC 60811-505 standard, the sample was placed in a -40℃ freezing chamber for 4 hours and the elongation of the sample was tested.

[0036] Tear resistance test: According to Section 5.5 of IEC 62893-2, the tensile force required to tear a 100mm×30mm×3mm sample to the stop line (80mm away) at a tensile rate of (250±50)mm / min is measured.

[0037] The change rate is the ratio of the physical properties of the sample after treatment to the physical properties of the sample before treatment. For example, the tensile strength of Example 1 is 23.133 MPa, and the tensile strength of Example 1 after aging treatment is 21.887 MPa. Then, the change rate (%) of the tensile strength of Example 1 after aging can be calculated as 23.133 / 21.887*100% = 94.6.

[0038] Table 1 below reveals the composition of pure TPU (Comparative Example 1) and TPU / graphene oxide composite materials (Examples 1-5) and the results of their property tests before and after aging.

[0039] Table 1

[0040] As shown in Table 1, compared to pure TPU without graphene oxide (Comparative Example), TPU with graphene oxide (Examples 1-5) exhibits superior cooling efficiency while maintaining good mechanical properties. "Good mechanical properties" include a tensile strength greater than or equal to 10 MPa and an elongation greater than or equal to 300%.

[0041] Table 2 below reveals the composition of pure TPU (comparative example) and TPU / graphene oxide composite materials (Examples 3 and 4) and the results of aging, oil resistance, hydrolysis resistance, acid resistance, alkali resistance, low temperature elongation, and tear resistance tests.

[0042] Table 2

[0043] Table 2 shows that the composite material of the present invention exhibits a tensile strength change rate greater than 70% and an elongation change rate greater than 70% after aging; a tensile strength change rate greater than 70% and an elongation change rate greater than 70% after oil resistance testing; a tensile strength change rate greater than 70% and an elongation change rate greater than 70% after hydrolysis resistance testing; a tensile strength change rate greater than 60% and an elongation change rate greater than 100% after acid resistance testing; and a tensile strength change rate greater than 60% and an elongation change rate greater than 100% after alkali resistance testing. These experimental results demonstrate that the composite material of the present invention retains similar mechanical properties to its untreated state after aging, oil resistance, hydrolysis resistance, acid resistance, and alkali resistance testing, proving that the composite material of the present invention possesses anti-aging, oil resistance, hydrolysis resistance, acid resistance, and alkali resistance characteristics. Furthermore, the composite material of the present invention exhibits a low-temperature elongation greater than 30% and a tear resistance greater than 25 N / mm.

[0044] The composite material of this invention exhibits excellent aging resistance, maintaining its physical properties and appearance even after prolonged exposure to high temperatures and oxidation. This characteristic contributes to the long-term reliability of the cable and provides it with good safety and a long lifespan.

[0045] The composite material of this invention exhibits excellent oil resistance and maintains stable properties when in contact with oil or in oil-contaminated environments. This characteristic is beneficial for its application in industrial and specific environments, and provides cables with good safety and long service life.

[0046] The composite material of this invention exhibits excellent acid and alkali resistance, enabling it to withstand corrosion from certain concentrations of acids and alkalis, thus maintaining its stability even in highly corrosive chemical environments. This characteristic is advantageous for its application in specific environments and provides cables with good safety and long service life.

[0047] The composite material of this invention has excellent hydrolysis resistance and is not easily degraded by moisture. This characteristic is beneficial for its application in outdoor or high-humidity environments, and provides the cable with good safety and long service life.

[0048] The composite material of this invention has excellent tear resistance and can resist external physical damage. This property helps protect the internal structure and functional components of the cable from damage, providing the cable with good safety.

[0049] In summary, the composite material provided by this invention achieves the advantages of both excellent mechanical properties and heat dissipation by adding graphene oxide to thermoplastic polyurethane. Furthermore, the composite material of this invention possesses properties of anti-aging, oil resistance, hydrolysis resistance, acid resistance, alkali resistance, and tear resistance. In addition, cables manufactured from it can exhibit good safety, heat dissipation, flexibility, and long service life.

Claims

1. A composite material comprising: Thermoplastic polyurethane (TPU); and Graphene oxide; in, The weight ratio of thermoplastic polyurethane to graphene oxide is 9:1 to 7:

3.

2. The composite material as described in claim 1, wherein, The weight ratio of thermoplastic polyurethane to graphene oxide is 4:

1.

3. The composite material as described in claim 1, wherein the graphene oxide is modified with amino groups.

4. The composite material as described in claim 1, The weight average molecular weight of thermoplastic polyurethane is 130,000.

5. The composite material as described in claim 1, wherein the tensile strength measured according to ASTM D638 is greater than or equal to 10 megapascals (MPa).

6. The composite material as described in claim 1, wherein the elongation measured according to ASTM D638 is greater than or equal to 300%.

7. The composite material as described in claim 1 has a withstand voltage greater than or equal to 2.0 kV as measured by ASTM D149.

8. The composite material as described in claim 1 has a leakage current of less than 0.5 mA as measured according to ASTM D149.

9. Use of the composite material as described in claim 1 in the manufacture of a cable.

10. A method for manufacturing a heat-dissipating composite material for cables, comprising: Graphene oxide was modified using an aminosilane coupling agent, and then thermoplastic polyurethane in a weight ratio of 9:1 to 7:3 was mixed with the modified graphene oxide using a twin-screw extrusion compound to create a heat dissipation composite material for cables.

Images