CN105017604B - Preparation method of nanometer ferroferric oxide/polyethylene thermally conductive composite material - Google Patents

Abstract

The preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material, it are related to a kind of heat-conductive composite material containing inorganic conductive particle.The invention aims to solving the technical problem of polyethylene low thermal conductivity.This method is as follows:Take ferroso-ferric oxide and polyethylene is placed in alcohol and is stirred mixing and pours heating in hydrothermal synthesis reaction kettle into, filter, drying is hot-forming, plus magnetic, obtains final product.The present invention prepares nano-particle in gained nano ferriferrous oxide/composite polyethylene material and is uniformly dispersed, and ferroso-ferric oxide significantly improves the capacity of heat transmission of polyethylene, the composite particularly plus after magnetic treatment.The invention belongs to the preparation field of heat-conductive composite material.

Description

Preparation method of nanometer ferroferric oxide/polyethylene thermally conductive composite material

technical field

The invention relates to a heat-conducting composite material containing inorganic heat-conducting particles.

Background technique

Polyethylene (PE) is a light and non-toxic polymer insulating material, which has excellent electrical insulation and dielectric properties, low temperature resistance, and sufficient mechanical properties, so it has been widely used. However, the shortcomings of polyethylene are also obvious. Its thermal conductivity is only 0.28-0.44W/m·K, and its operating temperature range is narrow. The thermal conductivity of metals and their oxides is large, generally 100 times or more that of polymer materials, so filling them as thermally conductive fillers in polymer materials can improve their thermal conductivity. The preparation of thermally conductive and electrically insulating polyethylene can give full play to the inherent excellent electrical properties of polyethylene and the high thermal conductivity of composite materials. This type of material is used for insulation and heat dissipation, packaging and other special applications of electronic devices in some occasions with low heat resistance. In addition to its application, it can also be used for heat dissipation in non-insulated occasions.

Contents of the invention

The purpose of the present invention is to solve the technical problem of low thermal conductivity of polyethylene, and provide a preparation method of a nanometer ferroferric oxide/polyethylene thermally conductive composite material.

The preparation method of nano ferric oxide/polyethylene heat conducting composite material is as follows:

1. Put ferric oxide and polyethylene in alcohol and stir and mix to obtain a suspension. The mass ratio of ferric oxide and polyethylene in the suspension is 1% to 30%;

2. Pour the suspension obtained in step 1 into a hydrothermal synthesis reactor with a filling ratio of 70-85%, and keep it warm for 1-24 hours at a temperature of 100-130°C;

3. Pour out the suspension from the hydrothermal synthesis reaction kettle, filter, and dry at 50°C for 1 to 12 hours to obtain a mixed powder;

4. Put the mixed powder in step 3 in the mold and put it on a flat vulcanizing machine. Under the conditions of pressure of 0-10MPa and molding temperature of 110-130°C, pressurize for 5min-35min and then cool to room temperature. Obtain thermally conductive composite materials;

5. Magnetize the heat-conducting composite material obtained in step 4 for 30 minutes at a heating temperature of 110-130°C and a magnetic current of 10-16A, and then lower the temperature to 15-60°C to obtain nanometer ferroferric oxide/polymer Vinyl thermally conductive compound.

Since the density of polyethylene is less than 1 and the density of ferroferric oxide is greater than 1, polyethylene will float on the water when the water bath method is used, and ferric oxide will sink to the bottom of the water, so ferric oxide cannot grow on the surface of polyethylene uniform. The present invention selects the solvothermal method, and the solvent is alcohol, because the density of alcohol is lower than that of polyethylene and ferric oxide, so that ferric ferric oxide can be evenly grown on the surface of polyethylene. When the ferroferric oxide/polyethylene heat conduction composite material is subjected to magnetic treatment, the heat conduction channel can be formed more easily, and the heat conduction capacity can be further improved.

In the present invention, the preparation method of nanometer ferric oxide/polyethylene thermally conductive composite material provides a new composite method for the metal oxide/polyethylene composite material, and the ferric ferric oxide produced is coated on the surface through the solution synthesis method. The surface of the polyethylene, and the composite material is subjected to magnetic treatment, the preparation process and the required equipment are simple, the cost is low, and the implementation is easy. The nanometer particles in the prepared nanometer ferroferric oxide/polyethylene composite material are uniformly dispersed, and the ferroferric oxide significantly improves the thermal conductivity of polyethylene, especially the composite material after magnetic treatment.

Description of drawings

Fig. 1 is the XRD spectrum of the nanometer ferric oxide/polyethylene heat-conducting composite material prepared in experiment one, among the figure ◆ represents polyethylene, ● represents ferric oxide;

Fig. 2 is the thermal conductivity curve comparison figure of the heat conduction composite material prepared in step 4 in the experiment one and the nanometer ferroferric oxide/polyethylene heat conduction composite material, among the figure 1 represents the thermal conductivity of the nanometer ferroferric oxide/polyethylene heat conduction composite material Conductivity curve, 2 represents the thermal conductivity curve of the thermally conductive composite material prepared in step 4;

Figure 3 is a schematic flow chart of the preparation of mixed powder in Step 3 of Experiment 1.

detailed description

The technical solution of the present invention is not limited to the specific embodiments listed below, but also includes any combination of the specific embodiments.

Specific implementation mode 1: The preparation method of the nano-ferric oxide/polyethylene heat-conducting composite material in this implementation mode is as follows:

1. Put ferric oxide and polyethylene in alcohol and stir and mix to obtain a suspension. The mass ratio of ferric oxide and polyethylene in the suspension is 1% to 30%;

2. Pour the suspension obtained in step 1 into a hydrothermal synthesis reactor with a filling ratio of 70-85%, and keep it warm for 1-24 hours at a temperature of 100-130°C;

3. Pour out the suspension from the hydrothermal synthesis reaction kettle, filter, and dry at 50°C for 1 to 12 hours to obtain a mixed powder;

4. Put the mixed powder in step 3 in the mold and put it on a flat vulcanizing machine. Under the conditions of pressure of 0-10MPa and molding temperature of 110-130°C, pressurize for 5min-35min and then cool to room temperature. Obtain thermally conductive composite materials;

5. Magnetize the heat-conducting composite material obtained in step 4 for 30 minutes at a heating temperature of 110-130°C and a magnetic current of 10-16A, and then lower the temperature to 15-60°C to obtain nanometer ferroferric oxide/polymer Vinyl thermally conductive compound.

Embodiment 2: The difference between this embodiment and Embodiment 1 is that the mass ratio of ferric iron tetroxide to polyethylene in step 1 is 1%. Others are the same as in the first embodiment.

Embodiment 3: This embodiment differs from Embodiment 1 or Embodiment 2 in that the mass ratio of ferric iron tetroxide to polyethylene in step 1 is 5%. Others are the same as those in the first or second embodiment.

Embodiment 4: The difference between this embodiment and one of Embodiments 1 to 3 is that the mass ratio of ferric iron tetroxide to polyethylene in step 1 is 10%. Others are the same as those in the first to third specific embodiments.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that the temperature in the hydrothermal synthesis reactor in step 2 is 110° C. and the temperature is kept for 4 hours. Others are the same as one of the specific embodiments 1 to 4.

Embodiment 6: This embodiment differs from Embodiment 1 to Embodiment 5 in that the temperature in the hydrothermal synthesis reactor in step 2 is 120° C. and the temperature is kept for 6 hours. Others are the same as one of the specific embodiments 1 to 5.

Embodiment 7: This embodiment differs from Embodiment 1 to Embodiment 6 in that the temperature in the hydrothermal synthesis reactor in step 2 is 130° C. and the temperature is kept for 8 hours. Others are the same as one of the specific embodiments 1 to 6.

Embodiment 8: The difference between this embodiment and one of Embodiments 1 to 7 is that in Step 5, the heat-conducting composite material obtained in Step 4 is placed in an SBV double-yoke single-tuned adjustable air gap electromagnet, and the temperature is raised to 130°C. , Turn on the current to start magnetization, adjust the magnetic current to 16A, stop heating after 30 minutes of heat preservation, and turn off the current after the temperature drops to 60°C. Others are the same as one of the specific embodiments 1 to 7.

Adopt following experiment verification effect of the present invention:

experiment one:

The preparation method of the nano ferroferric oxide/polyethylene heat-conducting composite material is realized according to the following steps:

1. Place iron ferric oxide and polyethylene in alcohol and stir and mix. The mass ratio of ferric oxide and polyethylene in the suspension is 15%.

2. Pour the suspension obtained in Step 1 into a hydrothermal synthesis reaction kettle with a filling ratio of 80%, a temperature of 110° C., and keep warm for 4 hours.

3. Pour out the suspension from the hydrothermal kettle, filter, and dry at 50°C for 12 hours to obtain a mixed powder.

4. Put the mixed powder into the flat vulcanizing machine. The molding temperature on the flat vulcanizing machine is 120°C. Pressurize at 0MPa for 5min, pressurize at 5MPa for 5min, pressurize at 10MPa for 5min, and pressurize at 15MPa for 5min. Cool to room temperature to obtain a thermally conductive composite material.

5. Place the heat-conducting composite material in step 4 in the SBV double-yoke single-tuning adjustable air-gap electromagnet, heat up to 130°C, turn on the current and start magnetizing, adjust the magnetic current to 16A, stop heating after 30 minutes of heat preservation, and the temperature After the temperature is lowered to 60°C, the current is turned off, and the nano-ferric oxide/polyethylene heat-conducting composite material is obtained.

The mass fraction of ferric oxide in the nanometer iron ferric oxide/polyethylene heat conducting composite material obtained in this experiment is 15%.

In the process of preparing nano-ferric oxide/polyethylene heat-conducting composite powder, ferric oxide and polyethylene powder are mechanically stirred, and ferric oxide will stick to the surface of polyethylene. Under the conditions of high temperature and high pressure in a hydrothermal kettle, Ferroferric oxide crystals will grow and coat the polyethylene surface. Fig. 1 is the XRD pattern of the composite material after the ferroferric oxide content is 15% and the magnetization is applied. The thermal conductivity of the composite material was measured by the LFA447 laser thermal conductivity meter test, and the thermal conductivity of the 15% mass fraction of nanometer iron tetroxide/polyethylene thermal conductivity composite material after solvothermal heating increased compared with that of pure polyethylene. 30.16%. Based on the above data, it can be obtained that the composite material coated with polyethylene by nanometer ferroferric oxide and subjected to magnetic treatment has good thermal conductivity.

Claims (8)

1. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material, it is characterised in that nano ferriferrous oxide/poly- The preparation method of ethene heat-conductive composite material is as follows：

First, take ferroso-ferric oxide and polyethylene is placed in alcohol and mixing is stirred, suspension is obtained, four oxidation three in suspension Iron is 1%～30% with the mass ratio of polyethylene；

2nd, step one gained suspension is poured in hydrothermal synthesis reaction kettle, packing ratio be 70～85%, temperature be 100～ 1～24h is incubated under conditions of 130 DEG C；

3rd, suspension is poured out from hydrothermal synthesis reaction kettle, is filtered, dry 1～12h at 50 DEG C, obtain mixed-powder；

4th, the mixed-powder in step 3 is placed in mould and is placed on vulcanizing press, be 0～10MPa, be molded temperature in pressure Spend for, under conditions of 110～130 DEG C, 5min～35min is hot-forming for pressurization, is cooled to room temperature, obtains heat-conductive composite material；

5th, step 4 gained heat-conductive composite material is 110～130 DEG C, adds the condition that magnetoelectricity stream is 10～16A in heating-up temperature Down plus magnetic treatment 30min, then it is cooled to 15～60 DEG C, obtains final product nano ferriferrous oxide/polyethylene heat-conductive composite material.

2. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that Ferroso-ferric oxide described in step one is 1% with the mass ratio of polyethylene.

3. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that Ferroso-ferric oxide described in step one is 5% with the mass ratio of polyethylene.

4. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that Ferroso-ferric oxide described in step one is 10% with the mass ratio of polyethylene.

5. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that In step 2, in hydrothermal synthesis reaction kettle, temperature is 110 DEG C, is incubated 4h.

6. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that In step 2, in hydrothermal synthesis reaction kettle, temperature is 120 DEG C, is incubated 6h.

7. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that In step 2, in hydrothermal synthesis reaction kettle, temperature is 130 DEG C, is incubated 8h.

8. the preparation method of nano ferriferrous oxide/polyethylene heat-conductive composite material according to claim 1, it is characterised in that Gained heat-conductive composite material in step 4 is placed in the double yoke single tuning adjustable air gap electromagnet of SBV in step 5, heat temperature raising To 130 DEG C, open electric current and start plus magnetic, plus magnetoelectricity stream is adjusted to 16A, stops heating after insulation 30min, after temperature is down to 60 DEG C, Close electric current.