Highly thermally conductive polypropylene composite material and method for producing the same

Abstract

The application relates to a high-thermal-conductivity polypropylene composite material and a preparation method thereof. The application belongs to the technical field of polymer materials. The high-thermal-conductivity polypropylene composite material is prepared from raw materials including the following components in parts by weight: 25-55 parts of polypropylene, 15-25 parts of boron nitride powder, 15-25 parts of modified boron nitride microparticles, 15-25 parts of modified boron nitride nanosheets, 0.1-0.5 parts of an antioxidant and 0.1-0.5 parts of a lubricant; wherein the total weight parts of the polypropylene, the boron nitride powder, the modified boron nitride microparticles and the modified boron nitride nanosheets are 100 parts. The high-thermal-conductivity polypropylene composite material has the advantage of high thermal conductivity and can be applied to the fields of automobiles, aviation, electronics and electrical appliances and household appliances.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high polymer materials, and particularly relates to a high-thermal-conductivity polypropylene composite material and a preparation method thereof. BACKGROUND

[0002] With the rapid development of the microelectronic integration field and the new energy automobile field, heat dissipation of electronic components or batteries has become an important problem. In order to not affect the performance and service life of the components, a composite material with thermal conductivity and electrical insulation needs to be prepared, which can effectively rapidly transfer the heat on the components. The metal material has good thermal conductivity but poor electrical insulation; the ceramic material has poor processing performance; the polypropylene material has excellent processing performance, good electrical insulation and corrosion resistance but poor thermal conductivity. Therefore, it is an urgent technical problem in the field to provide a high-thermal-conductivity polypropylene composite material. SUMMARY

[0003] One of the purposes of the application is to provide a high-thermal-conductivity polypropylene composite material to solve the problem of low thermal conductivity of the existing polypropylene composite material in the background art.

[0004] The second purpose of the application is to provide a preparation method of the high-thermal-conductivity polypropylene composite material.

[0005] The purposes of the application can be achieved by the following technical solutions.

[0006] In a first aspect, a high-thermal-conductivity polypropylene composite material comprises the following components in terms of weight fraction:

[0007]

[0008]

[0009] The total weight fraction of the polypropylene, the boron nitride powder, the modified boron nitride microparticle and the modified boron nitride nanoparticle is 100 parts.

[0010] Further, the modified boron nitride microparticle is prepared by the following steps:

[0011] The saturated sucrose aqueous solution, the titanate coupling agent and the boron nitride powder are ground at a mass ratio of 200:1:10 at room temperature (25-30 DEG C) at a speed of 200-300 r / min for 2 h, and then filtered, washed and dried to obtain the modified boron nitride microparticle.

[0012] Further, the modified boron nitride nanoparticle is prepared by the following steps:

[0013] The saturated sucrose aqueous solution, titanate coupling agent and boron nitride powder are ground at room temperature for 10h at a rotating speed of 200-300r / min in a mass ratio of 200:1:10, and the modified boron nitride nanosheet is obtained by filtering, washing and drying.

[0014] Further, the polypropylene (PP) is selected from at least one of copolymerized polypropylene and homopolymerized polypropylene.

[0015] Further, the boron nitride powder has a particle size of 10-20 microns.

[0016] Further, the modified boron nitride microparticle has a particle size of 1-2 microns.

[0017] Further, the modified boron nitride nanosheet has a particle size of 100-200 nanometers.

[0018] Further, the antioxidant is selected from at least one of phenols, phosphite esters and sulfur-containing esters.

[0019] Further, the lubricant is selected from at least one of zinc stearate and calcium stearate.

[0020] In a second aspect, a preparation method of the high-thermal-conductivity polypropylene composite material comprises the following steps:

[0021] S1. The components are weighed and mixed according to the weight ratio to obtain a uniformly mixed mixture;

[0022] S2. The mixture is fed into a double-screw extruder, and is subjected to melting, extrusion and granulation to obtain the high-thermal-conductivity polypropylene composite material.

[0023] The process parameters of the double-screw extruder include: a temperature of 180-220 DEG C, a screw rotating speed of 450-650 rpm, and a vacuum degree of >0.06 MPa.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The present application uses boron nitride powder, boron nitride microparticle and boron nitride nanosheet with three different sizes to form a stable and effective thermal conduction network, thereby effectively improving the thermal conductivity of the polypropylene composite material. The hydroxyl or carboxyl group on the surface of boron nitride reacts with the titanate coupling agent to form a chemical bond. The presence of the sucrose aqueous solution provides an additional solvent environment for the system, further affects the reaction rate and efficiency of the coupling of the titanate coupling agent and boron nitride, and provides a solvent basis for the modification of boron nitride with different particle sizes. After the modification of boron nitride by the titanate coupling agent, the interfacial energy between boron nitride and PP is greatly reduced, the thermal resistance is effectively reduced, the thermal conductivity of the composite material is further improved, and the high-thermal-conductivity polypropylene composite material is obtained.

[0026] 2. The preparation process is simple, the condition is controllable, the requirement for equipment is low, the performance is stable, the production cost is low, the process is simple, and the process is suitable for industrialized production, and can be widely applied to the fields of automobiles, aviation, electronics, electrical appliances and household appliances. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0028] In the following preparation examples, embodiments or comparative examples:

[0029] The polypropylene is copolymerized polypropylene PP-EP548R, which is selected from Sinopec Chemical Sales Co., Ltd.

[0030] The boron nitride powder is BN0150 with a particle size of 10-20 microns, which is selected from Suzhou Jin Yi Material Technology Co., Ltd.

[0031] The antioxidant is composed of antioxidant 1010 and antioxidant 168 with a mass ratio of 1:1; the antioxidant 1010 and the antioxidant 168 are selected from BASF.

[0032] The lubricant is zinc stearate, which is selected from Gaomi City Xingwei Additive Co., Ltd.

[0033] Preparation Example 1

[0034] The modified boron nitride microparticle is prepared by the following steps:

[0035] The saturated sucrose aqueous solution, the titanate coupling agent and the boron nitride powder are put into a grinding tank according to a mass ratio of 200:1:10, and are ground at a speed of 250 r / min under room temperature for 2 h, and then are filtered, washed and dried to obtain the modified boron nitride microparticle.

[0036] The modified boron nitride microparticle in the following embodiments or comparative examples is prepared by the present preparation example.

[0037] Preparation Example 2

[0038] The modified boron nitride nanosheet is prepared by the following steps:

[0039] The saturated sucrose aqueous solution, the titanate coupling agent and the boron nitride powder are put into a grinding tank according to a mass ratio of 200:1:10, and are ground at a speed of 250 r / min under room temperature for 8 h, and then are filtered, washed and dried to obtain the modified boron nitride nanosheet.

[0040] The modified boron nitride nanoplatelets in the following examples or comparative examples are prepared by the present preparation example.

[0041] Preparation Example 3

[0042] The boron nitride microplatelets are prepared by the following steps:

[0043] A saturated sucrose aqueous solution and boron nitride powder are put into a grinding tank according to a mass ratio of 200:10, and are ground at a speed of 250 r / min for 2 h at room temperature. After filtration, washing and drying, the boron nitride microplatelets are obtained.

[0044] The boron nitride microplatelets in the following examples or comparative examples are prepared by the present preparation example.

[0045] Preparation Example 4

[0046] The boron nitride nanoplatelets are prepared by the following steps:

[0047] A saturated sucrose aqueous solution and boron nitride powder are put into a grinding tank according to a mass ratio of 20:10, and are ground at a speed of 250 r / min for 8 h at room temperature. After filtration, washing and drying, the boron nitride nanoplatelets are obtained.

[0048] The boron nitride nanoplatelets in the following examples or comparative examples are prepared by the present preparation example.

[0049] A laser particle size analyzer is used to test the particle size distribution of the boron nitride particles by the laser scattering principle. The test results are shown in Table 1:

[0050] Table 1

[0051] Sample D50 Boron nitride powder 15.4 μm Preparation Example 1 Modified boron nitride microsheet 1.52 μm Preparation Example 2 Modified boron nitride nanosheet 155 nm Preparation Example 3 Boron nitride microsheet 1.55 μm Preparation Example 4 Boron nitride nanosheet 157 nm

[0052] Example 1

[0053] A high-thermal-conductivity polypropylene composite material includes the following components in parts by weight:

[0054]

[0055] The total weight of the polypropylene, boron nitride powder, modified boron nitride microplatelets and modified boron nitride nanoplatelets is 100 parts.

[0056] The preparation method of the high-thermal-conductivity polypropylene composite material includes the following steps:

[0057] S1. The polypropylene, boron nitride powder, modified boron nitride microplatelets, modified boron nitride nanoplatelets, antioxidant and lubricant are weighed in parts by weight and fully mixed to obtain a uniformly mixed mixture;

[0058] S2. The mixture is fed into a twin-screw extruder, and the process parameters are as follows: temperature 180℃, screw speed 550rpm, vacuum degree >0.06MPa. After melting, extrusion and granulation, a high-thermal-conductivity polypropylene composite material is obtained.

[0059] Example 2

[0060] A high-thermal-conductivity polypropylene composite material comprises the following components in parts by weight:

[0061]

[0062] The total weight of the polypropylene, boron nitride powder, modified boron nitride microparticles and modified boron nitride nanoparticles is 100 parts.

[0063] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Example 1.

[0064] Example 3

[0065] A high-thermal-conductivity polypropylene composite material comprises the following components in parts by weight:

[0066]

[0067] The total weight of the polypropylene, boron nitride powder, modified boron nitride microparticles and modified boron nitride nanoparticles is 100 parts.

[0068] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Example 1.

[0069] Example 4

[0070] A high-thermal-conductivity polypropylene composite material comprises the following components in parts by weight:

[0071]

[0072]

[0073] The total weight of the polypropylene, boron nitride powder, modified boron nitride microparticles and modified boron nitride nanoparticles is 100 parts.

[0074] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Example 1.

[0075] Example 5

[0076] A high-thermal-conductivity polypropylene composite material comprises the following components in parts by weight:

[0077]

[0078] The total weight parts of the polypropylene, boron nitride powder, modified boron nitride microparticle, and modified boron nitride nanoparticle are 100 parts.

[0079] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Embodiment 1.

[0080] Embodiment 6

[0081] A high-thermal-conductivity polypropylene composite material includes the following components in terms of weight parts:

[0082]

[0083] The total weight parts of the polypropylene, boron nitride powder, modified boron nitride microparticle, and modified boron nitride nanoparticle are 100 parts.

[0084] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Embodiment 1.

[0085] Embodiment 7

[0086] A high-thermal-conductivity polypropylene composite material includes the following components in terms of weight parts:

[0087]

[0088] The total weight parts of the polypropylene, boron nitride powder, modified boron nitride microparticle, and modified boron nitride nanoparticle are 100 parts.

[0089] The preparation method of the high-thermal-conductivity polypropylene composite material is the same as that in Embodiment 1.

[0090] Embodiment 8

[0091] A high-thermal-conductivity polypropylene composite material includes the following components in terms of weight parts:

[0092]

[0093] The total weight parts of the polypropylene, boron nitride powder, modified boron nitride microparticle, and modified boron nitride nanoparticle are 100 parts.

[0094] The preparation method of the high-thermal-conductivity polypropylene composite material includes the following steps:

[0095] S1. The polypropylene, boron nitride powder, modified boron nitride microparticle, modified boron nitride nanoparticle, antioxidant, and lubricant are weighed in terms of weight parts and fully mixed to obtain a mixed material with uniform mixing;

[0096] S2. The mixed material is fed into a double-screw extruder, melted, extruded, and granulated to obtain the high-thermal-conductivity polypropylene composite material.

[0097] Further, the process parameters of the double screw extruder include: temperature 220℃, screw rotation speed 550rpm, vacuum degree >0.06MPa.

[0098] Comparative Example 1

[0099] A polypropylene composite material includes the following components in parts by weight:

[0100] Polypropylene 100 parts;

[0101] Antioxidant 0.1 part;

[0102] Lubricant 0.1 part;

[0103] The preparation method of the polypropylene composite material is the same as that of Example 1.

[0104] Comparative Example 2

[0105] A polypropylene composite material includes the following components in parts by weight:

[0106]

[0107] The total weight parts of polypropylene and boron nitride powder are 100 parts.

[0108] The preparation method of the polypropylene composite material is the same as that of Example 1.

[0109] Comparative Example 3

[0110] A polypropylene composite material includes the following components in parts by weight:

[0111]

[0112]

[0113] The total weight parts of polypropylene, boron nitride powder and modified boron nitride microparticle are 100 parts.

[0114] The preparation method of the polypropylene composite material is the same as that of Example 1.

[0115] Comparative Example 4

[0116] A polypropylene composite material includes the following components in parts by weight:

[0117]

[0118] The total weight parts of polypropylene, boron nitride powder and modified boron nitride microparticle are 100 parts.

[0119] The preparation method of the polypropylene composite material is the same as that of Example 1.

[0120] Comparative Example 5

[0121] A polypropylene composite material, comprising the following components in parts by weight:

[0122]

[0123] The total weight parts of the polypropylene, the boron nitride powder, the boron nitride microparticle, and the boron nitride nanoparticle is 100 parts.

[0124] The preparation method of the polypropylene composite material is the same as that of Example 1.

[0125] The raw materials and the weight parts in the above examples and comparative examples are compared in Table 2.

[0126] Table 2

[0127]

[0128] a: The temperature of the parallel twin-screw extruder is changed.

[0129] The polypropylene composite materials prepared in Examples 1-8 and Comparative Examples 1-5 are tested for performance: the thermal conductivity is tested according to the GB / T10297 standard, and the test model is the Cowan model + pulse correction. The test results are shown in Table 3.

[0130] Table 3

[0131]

[0132]

[0133] a: The temperature of the parallel twin-screw extruder is changed.

[0134] As can be seen from the test results in Table 3, Examples 1-7 adjust the addition amount of the boron nitride powder, the modified boron nitride microparticle, and the modified boron nitride nanoparticle. With the increase of the addition amount, the thermal conductivity of the obtained polypropylene composite material shows an increasing trend, which is mainly because the increase of the filler amount can perfect the thermal conduction network and effectively reduce the thermal resistance.

[0135] Compared with Example 7, the temperature of the parallel twin-screw extruder in Example 8 is 220℃, and the temperature of the parallel twin-screw extruder in Example 7 is 180℃. By comparison, it can be found that the thermal conductivity of the polypropylene composite material prepared by using the temperature of the parallel twin-screw extruder in Example 8 is slightly improved, which is because the increase of the extrusion temperature is beneficial to the dispersion of the material.

[0136] Compared with Example 2, the thermal conductivity of the polypropylene composite material prepared in Comparative Example 1 is low, which is mainly because the filler is lacking to form a thermal conduction network.

[0137] Compared with Example 2, the polypropylene composite prepared in Comparative Example 2, Comparative Example 3 and Comparative Example 4 has low thermal conductivity, mainly because the three sizes of boron nitride fillers are not used in combination. The boron nitride powder is dispersed in the polypropylene matrix to form a "sea-island" with most of the dispersion and part of the contact, and the modified boron nitride microparticles and the modified boron nitride nanoplatelets are dispersed therein, which increases the contact area of the "sea-island" and forms a stable and effective thermal conduction network, thereby effectively improving the thermal conductivity of the composite material.

[0138] Compared with Example 2, the polypropylene composite prepared in Comparative Example 5 has low thermal conductivity, mainly because the boron nitride is not modified by the titanate coupling agent. After modification, the interface energy between the filler and PP is greatly reduced, which can effectively reduce the thermal resistance and further improve the thermal conductivity of the composite material, and a polypropylene composite with higher thermal conductivity is obtained.

[0139] In summary, the use of three sizes of boron nitride fillers in combination can effectively improve the thermal conductivity of the material, and after modification of the boron nitride filler by the titanate coupling agent, the thermal conductivity of the composite material can be further improved.

[0140] It should be noted that the relational terms herein, such as first and second, are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment.

[0141] Although embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made thereto without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A high thermal conductivity polypropylene composite material, characterized in that, Based on parts by weight, it includes the following components: 25-55 parts of polypropylene; 15-25 parts of boron nitride powder; 15-25 parts of modified boron nitride micron sheets; 15-25 parts of modified boron nitride nanosheets; Antioxidant 0.1-0.5 parts; Lubricant 0.1-0.5 parts; The total weight of polypropylene, boron nitride powder, modified boron nitride microsheets, and modified boron nitride nanosheets is 100 parts. The modified boron nitride microsheets are prepared by the following steps: Saturated sucrose aqueous solution, titanate coupling agent and boron nitride powder were ground at a mass ratio of 200:1:10 at room temperature and a rotation speed of 200-300 r / min for 2 h. The mixture was then filtered, washed and dried to obtain modified boron nitride micron flakes. The modified boron nitride nanosheets are prepared by the following steps: Saturated sucrose aqueous solution, titanate coupling agent and boron nitride powder were ground at a mass ratio of 200:1:10 at room temperature and a rotation speed of 200-300 r / min for 10 h. The mixture was then filtered, washed and dried to obtain modified boron nitride nanosheets. The boron nitride powder has a particle size of 10-20 micrometers; the modified boron nitride micron flakes have a particle size of 1-2 micrometers; and the modified boron nitride nanoflakes have a particle size of 100-200 nanometers.

2. The high thermal conductivity polypropylene composite material according to claim 1, characterized in that, The polypropylene is selected from at least one of copolymer polypropylene and homopolymer polypropylene.

3. The high thermal conductivity polypropylene composite material according to claim 1, characterized in that, The antioxidant is selected from at least one of phenols, phosphites, and sulfur-containing esters.

4. The high thermal conductivity polypropylene composite material according to claim 1, characterized in that, The lubricant is selected from at least one of zinc stearate and calcium stearate.

5. A method for preparing a high thermal conductivity polypropylene composite material as described in any one of claims 1-4, characterized in that, Includes the following steps: S1. Weigh each component according to the weight percentage and mix them to obtain a uniformly mixed mixture; S2. The mixture is fed into a twin-screw extruder, and after melting, extrusion, and granulation, a high thermal conductivity polypropylene composite material is obtained; The process parameters for a twin-screw extruder include: temperature of 180-220℃, screw speed of 450-650rpm, and vacuum degree >0.06MPa.

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