CN114395242B

CN114395242B - High-heat-conductivity POK composite material and preparation method and application thereof

Info

Publication number: CN114395242B
Application number: CN202210144674.3A
Authority: CN
Inventors: 王成城; 马涛
Original assignee: Waldorf Polymer Shanghai Co ltd
Current assignee: Suzhou Waldorf New Material Technology Co ltd
Priority date: 2022-02-17
Filing date: 2022-02-17
Publication date: 2024-01-19
Anticipated expiration: 2042-02-17
Also published as: CN114395242A

Abstract

The invention relates to the technical field of modified polymer composite materials, and discloses a high-heat-conductivity POK composite material and a preparation method thereof. The preparation raw materials of the high-heat-conductivity POK composite material comprise: 40-64 parts of POK resin; 5-35 parts of graphene; 15-30 parts of graphite; 2.0 to 10.0 portions of compatilizer. The preparation method of the high-heat-conductivity POK composite material comprises the following steps: mixing the raw materials, extruding, granulating, and oven drying. The composite material provided by the application has the advantages of good thermal conductivity, good chemical resistance, low water absorbability, high toughness and the like, and overcomes the defects of poor mechanical property, easiness in water absorbability, poor dimensional stability, high brittleness, poor chemical resistance and the like of the traditional heat conducting material, and the future application scene is wider.

Description

High-heat-conductivity POK composite material and preparation method and application thereof

Technical Field

The invention relates to the technical field of modified polymer composite materials, in particular to a high-heat-conductivity POK composite material, and a preparation method and application thereof.

Background

The POK resin (PK) is a novel polymer obtained by copolymerizing carbon monoxide, propylene and ethylene, and has the advantages of excellent chemical resistance, outstanding wear resistance, hydrolysis resistance, excellent low temperature resistance, low VOC (volatile organic compounds) and high barrier property due to the specificity of a molecular structure, is a novel environment-friendly material with far-reaching novel performance in recent years, is used as novel engineering plastic with outstanding wear resistance, the wear resistance of POK is 14 times that of POM, and has long-term dimensional stability, the POK can replace POM, nylon and other materials in the fields of pulleys, gears, bearings and the like, the performance retention rate of POK materials after water absorption is 30-40 percent higher than that of nylon, and meanwhile, the C-C chain segment structure of the POK determines that the chemical performance of the POK is very stable, other chemical environments are basically tolerant except strong acid and strong alkali, and the chemical resistance is basically equivalent to PPS. POK resin has a melting point of about 220 ℃ and can be used for a long time at 120 ℃, so that POK has been widely applied in the fields of automobiles, electronics, electrics, communication and the like.

However, with the gradual acceleration of current technological development, the requirements of equipment on material heat dissipation are higher and higher, the traditional metal heat dissipation material has larger weight, long processing period and large pollution, the POK serving as a thermoplastic material has poorer self heat conduction performance and cannot be applied to practice, the traditional heat conduction PA has the defects of poor chemical resistance, larger influence of environmental humidity on strength and size and the like, and the conventional heat conduction PPS has the problem of larger material brittleness and limited application field, so that the development of a novel heat conduction plastic for improving the problems is a problem to be solved urgently in the field of the current modified plastic.

In view of this, the present invention has been made.

Disclosure of Invention

The invention aims to provide a POK composite material with high heat conductivity, and a preparation method and application thereof.

The invention is realized in the following way:

in a first aspect, the invention provides a high thermal conductivity POK composite material, which is prepared from the following raw materials:

in an alternative embodiment, the POK resin is formed by compounding a high-viscosity resin and a low-viscosity resin in a ratio of 1:1.5-2;

the high viscosity resin is POK resin with weight average molecular weight of 170000-190000; the low viscosity resin is POK resin with weight average molecular weight of 120000-140000.

In an alternative embodiment, the graphene is in the form of microchip powder, and the number of the granular carbon layers is 10-20;

preferably, the particle thickness of the graphene is 5 to 100nm and the average particle diameter is 10 to 14 μm.

In an alternative embodiment, the graphite takes the form of graphite powder as a raw material, and the average particle size of the graphite powder is 10-400 mu m;

preferably, the graphite is one or two of natural graphite and synthetic graphite;

preferably, the carbon content of the graphite is greater than or equal to 95%.

In an alternative embodiment, the compatibilizer is at least one of POK-g-MAH, POE-g-MAH, and EMA-g-GMA.

In an alternative embodiment, the preparation of the feedstock further comprises: 0.1 to 0.3 part of antioxidant;

preferably, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 9228 and antioxidant 2450.

In an alternative embodiment, the preparation of the feedstock further comprises: 0.3-2 parts of lubricant;

preferably, the lubricant is selected from at least one of zinc stearate, calcium stearate, pentaerythritol stearate, ethylene bisstearamide, silicone masterbatch and talc.

In an alternative embodiment, the preparation of the feedstock further comprises: 0.01 to 12 parts of glass fiber;

preferably, the glass fibers are selected from at least one of alkali-free continuous glass fibers and alkali-free chopped glass fibers;

preferably, the alkali-free chopped glass fibers have a diameter of 7 to 13 μm.

In a second aspect, the present invention provides a method for preparing a high thermal conductivity POK composite material according to the foregoing embodiment, including:

uniformly mixing the preparation raw materials, extruding and granulating;

preferably, the preparation raw materials also comprise glass fibers, the extrusion granulation is carried out by adopting double-screw melt extrusion granulation, and the glass fibers are put into a double-screw extruder from a side feeding cylinder;

preferably, the twin-screw extrusion temperature is set to 190-255℃and the host rotation speed is 250-400rpm.

In a third aspect, the present invention provides the use of a high thermal conductivity POK composite material according to any one of the preceding embodiments or a high thermal conductivity POK composite material prepared according to the preparation method of the preceding embodiments in the automotive, electronic and electrical and communication fields.

The invention has the following beneficial effects:

the POK composite material with high heat conductivity mainly comprises POK resin, graphene serving as a heat conducting filler and graphite, and the POK composite material is modified by a heat conducting agent, so that the heat conductivity of the POK resin is improved; because the viscosity of the graphene microchip is higher and the dispersibility is poor, the graphene can be added alone to cause difficult processing and granulation, the processing is difficult, meanwhile, the flowability and the processing performance of the material are poor, and the flowability and the processing performance of the graphene and the graphene compounded and added into the POK resin are better than those of the graphene added alone; the heat conduction efficiency of the compounded graphene and the compounded graphene with proper proportion is higher than that of the graphene and the graphene which are independently added, the addition amount is smaller, and the formation of a heat conduction passage is facilitated; the POK resin has the problem of poor compatibility with the graphite and the graphene, the compatilizer in the components can improve the problem, the POK resin has good compatibility with the graphene and the graphite after being treated by the compatilizer, and the loss of mechanical properties is small. Therefore, the high-heat-conductivity POK composite material provided by the application has the advantages of good heat conductivity, good chemical resistance, low water absorbability, high toughness and the like. In addition, the C-C chain segment structure of the POK is more excellent in chemical resistance and acid and alkali resistance compared with heat-conducting nylon (PA) and heat-conducting polyphenylene sulfide (PPS), and can be used in a scene with chemical solvents for a long time. Therefore, the composite material provided by the application overcomes the defects of poor mechanical property, easy water absorption, poor dimensional stability, large brittleness, poor chemical resistance and the like of the traditional heat conduction material, and has wider future application scenes.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below. The specific conditions are not noted in the examples and are carried out according to conventional conditions or conditions recommended by the manufacturer. The reagents or apparatus used were conventional products commercially available without the manufacturer's attention.

The high-thermal-conductivity POK composite material provided by the application, and a preparation method and application thereof are specifically described below.

The preparation raw materials of the high-heat-conductivity POK composite material provided by the embodiment of the application comprise:

the POK composite material with high heat conductivity comprises the main components of POK resin, graphene serving as a heat conducting filler and graphite, and the POK composite material is modified by a heat conducting agent, so that the heat conductivity of the POK resin is improved; because the viscosity of the graphene microchip is higher and the dispersibility is poor, the graphene can be added alone to cause difficult processing and granulation, the processing is difficult, meanwhile, the flowability and the processing performance of the material are poor, and the flowability and the processing performance of the graphene and the graphene compounded and added into the POK resin are better than those of the graphene added alone; the heat conduction efficiency of the graphene and the graphite with proper proportion is higher than that of the graphene added singly or the graphene is smaller, and the formation of a heat conduction passage is facilitated; the POK resin has the problem of poor compatibility with the graphite and the graphene, the compatilizer in the components can improve the problem, the POK resin has good compatibility with the graphene and the graphite after being treated by the compatilizer, and the loss of mechanical properties is small. In conclusion, the high-heat-conductivity POK composite material provided by the application has the advantages of good heat conductivity, excellent chemical resistance, low water absorption, high toughness and the like. The composite material has better comprehensive performance compared with the traditional heat conducting material PA, PPS, PP.

Preferably, the POK resin is compounded by high-viscosity resin and low-viscosity resin in a ratio of 1:1.5-2 (such as 1:1.5, 1:1.7 or 1:2);

the high viscosity resin is a POK resin having a weight average molecular weight of 170000-190000 (e.g., 170000, 180000 or 190000); the low viscosity resin is a POK resin having a weight average molecular weight of 120000 to 140000 (e.g., 120000, 130000, or 140000).

The high viscosity resin has 60-70 g/10min under the testing condition of 240 ℃/2.16kg melt index, and the notch impact strength is kept between 11 KJ/m and 13KJ/m ² The method comprises the steps of carrying out a first treatment on the surface of the 180-200 g/10min of the low-viscosity resin under the testing condition of 240 ℃/2.16kg melt index, and the notch impact strength is kept at 5-7 KJ/m ² 。

The POK resin with higher weight average molecular weight has high viscosity, and the POK resin with different specific weight average molecular weight viscosities is compounded in a proper proportion in the preferred embodiment of the application, so that the high-heat-conductivity POK composite material with good processing fluidity, good impact resistance and high molding precision can be obtained.

Preferably, in order to obtain the high thermal conductivity POK composite material with better thermal conductivity and physical properties, the graphene is in the form of microchip powder, and the number of the carbon layers of particles is 10-20 (for example, 10, 15 or 20). Further, the graphene has a particle thickness of 5 to 100nm (e.g., 5nm, 10nm, 50nm, or 100 nm), and an average particle diameter of 10 to 14 μm (e.g., 10 μm, 12 μm, or 14 μm).

In order to obtain the high-thermal-conductivity POK composite material with better thermal conductivity and physical properties, graphite takes the form of graphite powder as a raw material, and generally, the larger the particle size of the graphite powder is, the easier a thermal conduction channel is formed in the material to enable the thermal conductivity to be higher, but the lower the mechanical property of the material is, so that a proper particle size range needs to be determined when the graphite powder is selected, and in a preferred scheme of the application, the average particle size of the graphite powder is 10-400 mu m (for example, 10 mu m, 50 mu m, 100 mu m or 400 mu m); specifically, the graphite is one or two of natural graphite and synthetic graphite; further, the carbon content of the graphite is greater than or equal to 95%.

Preferably, in order to make the compatibility of the POK resin, the graphene and the graphite better, the compatilizer is at least one of POK-g-MAH, POE-g-MAH and EMA-g-GMA.

Further, in order to improve the oxidation resistance of the composite material, the preparation raw materials further comprise: 0.1 to 0.3 part of antioxidant. Specifically, the antioxidant is at least one selected from the group consisting of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 9228 and antioxidant 2450.

Further, in order to improve the lubrication degree of each component in the high-heat-conductivity POK composite material, the influence of graphene and graphite on melt viscosity is reduced, and the melt extrusion is facilitated. The preparation raw materials also comprise: 0.3-2 parts of lubricant. Specifically, the lubricant is at least one selected from zinc stearate, calcium stearate, pentaerythritol stearate, ethylene bisstearamide, silicone masterbatch and talcum powder.

Further, in order to improve the mechanical properties of the composite material, the preparation raw materials further comprise: 0.01 to 12 parts of glass fiber. Preferably, the glass fibers are selected from at least one of alkali-free continuous glass fibers and alkali-free chopped glass fibers; when the glass fibers are alkali-free chopped glass fibers, the alkali-free chopped glass fibers used have a diameter of 7 to 13. Mu.m.

The preparation method of the high-heat-conductivity POK composite material provided by the embodiment of the application comprises the following steps:

mixing the above raw materials, extruding, and granulating.

The preparation method specifically comprises the following steps:

s1, weighing the corresponding POK resin, graphene, graphite, compatilizer, antioxidant, lubricant and glass fiber according to the parts by weight of the components, wherein the ratio of the high-viscosity resin to the low-viscosity resin is 1:1.5-2.

S2, mixing the weighed POK resin, graphene, graphite, a compatilizer, an antioxidant and a lubricant to obtain a mixed material.

And S3, putting glass fibers into the mixed material from a side feeding port, and then extruding, melting, granulating, drying and processing the glass fibers through double screws to obtain the high-heat-conductivity POK composite material.

Preferably, the extrusion device for the mixed material is a twin screw extruder. In the case of extrusion granulation in a twin-screw extruder, the glass fibers are fed from a side feed port, and if continuous, from a vent.

Further, the extrusion granulation process sets the host rotation speed to 250 to 400rpm (e.g., 250rpm, 300rpm, or 400 rpm), and the twin screw extrusion temperature to 190 to 255 ℃ (e.g., 190 ℃, 200 ℃, 230 ℃, or 255 ℃).

Further, in order to obtain good granulation effect, the twin-screw extrusion temperature is set from the feeding section to the head as follows: 210 ℃, 245 ℃, 240 ℃, 235 ℃, 250 ℃.

The features and capabilities of the present invention are described in further detail below in connection with the examples.

Example 1

The high-heat-conductivity POK composite material comprises the following preparation raw materials in parts by weight:

wherein, the POK resin (low viscosity) is selected from POK resin with weight average molecular weight of about 130000, and the POK resin (high viscosity) is selected from POK resin with weight average molecular weight of about 180000; the average particle size of the graphene powder was 14 μm, and the average particle size of the graphite was 10 μm.

The preparation method comprises the following steps:

the POK resin, the graphene, the graphite, the compatilizer, the antioxidant, the lubricant and the glass fiber are weighed according to the proportion.

And (3) removing glass fibers from the weighed raw materials to obtain a mixed material.

Glass fibers were fed into the mix from the side feed port and the host machine speed was set at 250rpm. The twin-screw extrusion temperature is set from the feeding section to the machine head as follows: 210 ℃, 245 ℃, 240 ℃, 235 ℃, 250 ℃ and then carrying out double-screw extrusion, melting granulation, drying and treatment to obtain the high-heat-conductivity POK composite material.

Example 2

the points not mentioned in this example are the same as in example 1.

Example 3

the points not mentioned in this example are the same as in example 1.

Example 4

the points not mentioned in this example are the same as in example 1.

Example 5

in this example, the average particle size of the natural graphite powder was 400. Mu.m.

The points not mentioned in this example are the same as in example 1.

Example 6

The points not mentioned in this example are the same as in example 1.

Example 7

the points not mentioned in this example are the same as in example 1.

Comparative example 1

This comparative example is substantially the same as example 6, except that: no compatibilizing agent was added.

Comparative example 2

This comparative example is substantially the same as comparative example 1, except that: the graphite powder and the graphene powder are completely replaced by 50 parts of graphite powder, and the composite material does not contain compatilizer.

Comparative example 3

This comparative example is substantially the same as the example, except that the graphene powder is completely replaced with the same amount of graphite powder.

Comparative example 4

This comparative example is substantially the same as the example, except that the graphite powder is completely replaced with an equivalent amount of graphene powder.

Comparative example 5

This comparative example is substantially identical with respect to the examples, except that: the preparation raw materials do not comprise graphite, graphene and compatilizer.

Experimental example

The method of granulating and injection molding by twin-screw extrusion is in accordance with ISO standard. The POK resins produced in examples 1 to 7 and comparative examples 1 to 3 were tested for properties, and the results are recorded in tables 1 to 2.

Table 1 Properties of the composite materials prepared in examples

Table 2 properties of the composite materials prepared in each comparative example

Table 3 results of the Performance test after absorption of water (85% RH,24 h) of the composites prepared in examples and comparative examples

The heat conductivity coefficient of the existing PPS material is about 3.0w, and the tensile strength is about 30 MPa; the heat conductivity coefficient of the existing PA material is about 3.0w, and the tensile strength is about 38 MPa. As can be seen from the table, the composite materials prepared in examples 1 to 7 have higher mechanical properties and heat conduction properties, the mechanical properties of the composite materials are superior to those of the existing PPS material and PA material, and the heat conduction properties of the composite materials are equivalent to those of the existing PPS material and PA material.

As can be seen from the comparison of the example 6 and the comparative example 1, the thermal conductivity of the prepared composite material is obviously poorer without adding the compatilizer, which indicates that the compatibility of the material with graphene and graphite is improved after the material is treated by the compatilizer, and the loss of mechanical property is smaller; as can be seen from comparison of several examples, the adjustment of the ratio change of the low viscosity and the high viscosity of the POK resin has a remarkable effect on the melt index of the composite material, so that the ratio relationship of the low viscosity and the high viscosity resin can be adjusted according to specific melt index requirements during production to obtain the composite material with good processing fluidity and impact resistance and high molding accuracy. As can be seen from comparing comparative example 1 with comparative example 2, when the heat conductive agent is only graphite, even if the addition amount is larger, the compound heat conductive effect is worse compared with the heat conductive agent which is graphite and graphene. As can be seen from comparing example 1 with comparative example 3, the composite material of comparative example 3 has poorer mechanical properties, which indicates that the properties of the material prepared by compounding graphene and graphite as the conductive agent are better than those of the material prepared by merely graphene as the conductive agent; as can be seen from a comparison of example 1 and comparative example 4, the composite material of comparative example 4 has poorer flow and processability, indicating that the properties of the material prepared when the conductive agent is graphene and graphite are compounded are better than when the conductive agent is graphite alone. As can be seen from comparing example 1 with comparative example 5, the thermal conductivity of comparative example 5 is poorer, and better comprehensive mechanical properties and thermal conductivity can be obtained by modifying POK resin with the electric conduction agent in the specification.

In summary, the high-thermal-conductivity POK composite material provided by the embodiment of the application mainly comprises POK resin, graphene serving as a thermal-conductive filler and graphite, and the thermal conductivity of the POK resin is improved by modifying the POK composite material by a thermal-conductive agent; because the viscosity of the graphene microchip is higher and the dispersibility is poor, the graphene can be added alone to cause difficult processing and granulation, the processing is difficult, meanwhile, the flowability and the processing performance of the material are poor, and the flowability and the processing performance of the graphene and the graphene compounded and added into the POK resin are better than those of the graphene added alone; the heat conduction efficiency of the compounded graphene and the compounded graphene with proper proportion is higher than that of the graphene and the graphene which are independently added, the addition amount is smaller, and the formation of a heat conduction passage is facilitated; the POK resin has the problem of poor compatibility with the graphite and the graphene, the compatilizer in the components can improve the problem, the POK resin has good compatibility with the graphene and the graphite after being treated by the compatilizer, and the loss of mechanical properties is small. Therefore, the high-heat-conductivity POK composite material provided by the application has the advantages of good heat conductivity, good chemical resistance, low water absorbability, high toughness and the like. In addition, the C-C chain segment structure of the POK is more excellent in chemical resistance and acid and alkali resistance compared with heat-conducting nylon (PA) and heat-conducting polyphenylene sulfide (PPS), and can be used in a scene with chemical solvents for a long time. Therefore, the composite material provided by the application overcomes the defects of poor mechanical property, easy water absorption, poor dimensional stability, large brittleness and poor chemical resistance of the traditional heat conduction material, and has wider future application scenes.

The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The POK composite material with high heat conductivity is characterized by comprising the following preparation raw materials:

40-64 parts of POK resin;

5-35 parts of graphene;

15-30 parts of graphite;

2.0-10.0 parts of compatilizer;

the POK resin is formed by compounding high-viscosity resin and low-viscosity resin in a ratio of 1:1.5-2;

the high viscosity resin is POK resin with weight average molecular weight of 170000-190000; the low viscosity resin is a POK resin with a weight average molecular weight of 120000-140000.

2. The high thermal conductivity POK composite material according to claim 1, wherein the graphene is in the form of microchip powder, and the number of the carbon layers of particles is 10-20.

3. The high thermal conductivity POK composite material of claim 1, wherein the graphene has a particle thickness of 5-100 nm and an average particle diameter of 10-14 μm.

4. The high thermal conductivity POK composite material according to claim 1, wherein the graphite is in the form of graphite powder, and the average particle size of the graphite powder is 10-400 μm.

5. The high thermal conductivity POK composite material of claim 4, wherein the graphite is one or both of natural graphite and synthetic graphite.

6. The high thermal conductivity POK composite material of claim 4, wherein the carbon content of the graphite is greater than or equal to 95%.

7. The high thermal conductivity POK composite material of claim 1, wherein the compatibilizer is at least one of POK-g-MAH, POE-g-MAH, EMA-g-GMA.

8. The high thermal conductivity POK composite material of claim 1, wherein the raw materials for preparation further comprise: 0.1-0.3 parts of an antioxidant.

9. The high thermal conductivity POK composite material of claim 8, wherein the antioxidant is selected from at least one of antioxidant 1010, antioxidant 1098, antioxidant 168, antioxidant 9228, and antioxidant 2450.

10. The high thermal conductivity POK composite material of claim 1, wherein the raw materials for preparation further comprise: 0.3-2 parts of lubricant.

11. The high thermal conductivity POK composite material of claim 10, wherein the lubricant is selected from at least one of zinc stearate, calcium stearate, pentaerythritol stearate, ethylene bisstearamide, silicone masterbatch, and talc.

12. The high thermal conductivity POK composite material of claim 1, wherein the raw materials for preparation further comprise: 0.01-12 parts of glass fiber.

13. The high thermal conductivity POK composite material of claim 12, wherein the glass fiber is selected from at least one of alkali-free continuous glass fiber and alkali-free chopped glass fiber.

14. The high thermal conductivity POK composite material of claim 13, wherein the alkali-free chopped glass fiber has a diameter of 7-13 μm.

15. The method for preparing the high thermal conductivity POK composite material according to any one of claims 1 to 14, comprising the steps of:

and uniformly mixing the preparation raw materials, extruding and granulating.

16. The method for preparing a high thermal conductivity POK composite material according to claim 15, wherein the preparation raw material further comprises glass fiber, extrusion granulation is performed by adopting double-screw melt extrusion granulation, and the glass fiber is fed into a double-screw extruder from a side feeding cylinder.

17. The method for preparing a high thermal conductivity POK composite material according to claim 15, wherein the twin-screw extrusion temperature is set to 190-255 ℃, and the host rotation speed is 250-400rpm.

18. Use of the high thermal conductivity POK composite material according to any one of claims 1 to 14 or the high thermal conductivity POK composite material prepared by the preparation method according to any one of claims 15 to 17 in the fields of automobiles, electronics and electrical and communication.