CN107828210A - A kind of graphene compound polyimide film and preparation method thereof - Google Patents

Abstract

The invention discloses a graphene composite polyimide film, which is composed of the following components in parts by weight: 150-300 parts of polyimide resin polymer, 1-2 parts of fullerene, and 0.1-2 parts of rare earth oxide 0.2 parts, modifier 2.5‑3.5 parts. The graphene composite polyimide film of the present invention has excellent mechanical properties, the elongation at break is greater than 40%, the thickness of the film is only 8-12 μm, the tensile strength at room temperature is greater than 200 MPa, and the elastic modulus is greater than 2.88 GPa, and it is wrinkle-free and smooth High density, volume resistivity 4.5×10 ¹ ‑3.7×10 ⁶ .

Description

A kind of graphene composite polyimide film and preparation method thereof

technical field

The invention relates to a polyimide film, in particular to a graphene composite polyimide film and a preparation method thereof.

Background technique

At present, the vigorous development of the aerospace industry has an increasingly urgent demand for polymer materials, but due to the impact of the space environment, there are strict requirements for the performance of polymer materials in all aspects. As a material with high heat resistance, polyimide also has high chemical stability, high mechanical properties, high radiation resistance and high processability, and has great application space in the aerospace industry. However, polyimide has a high resistivity, electrons are not easy to move in the material, and the accumulated charge is difficult to diffuse, which will form static electricity, and static electricity is extremely dangerous in the aerospace field, and it is easy to damage aviation equipment and damage electronic components.

As a new type of carbon material, graphene has a special two-dimensional structure, and electrons can move rapidly on its surface with almost no resistance, so it has good electrical conductivity. In addition, graphene has thermal, electrical and mechanical properties. The extremely excellent performance is much higher than other inorganic materials, and these are what some polymers lack, so graphene/polymer composite materials are gradually being valued in various research institutions.

At present, there have been a lot of reports on special polyimide composite film materials, but there are still problems such as cumbersome preparation, heavy pollution, low flatness of the final composite material, and unsatisfactory performance.

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned defects in the prior art, and obtain a polyimide composite film through reasonable component distribution and process improvement. The mechanical properties and electrical properties of the film are obviously improved, and the surface layer is uniform and flat, the yield rate is high, and the comprehensive quality is good.

A graphene composite polyimide film is composed of the following components in parts by weight:

150-300 parts of polyimide resin polymer, 1-2 parts of fullerene, 0.1-0.2 parts of rare earth oxide, 2.5-3.5 parts of modifier;

The polyimide resin polymer includes the following components in weight percentage: 0.2-1.5% of graphene, 1-5% of titanium dioxide, 0.5-6% of silica sol, 2-10% of fluorine-containing acrylate copolymer, polyamide The remainder of the imine resin, wherein the fluorine-containing acrylate copolymer is a hyperbranched polymer with a molecular weight of 3000-10000.

Preferably, the modifying agent is prepared from methyl salicylate and liquid paraffin in a weight ratio of (3-5):1.

Preferably, the polyimide resin polymer includes the following percentage components: graphene 0.5-0.75%, titanium dioxide 2-3%, silica sol 2-5%, fluorine-containing acrylate copolymer 3-6% %, the balance of polyimide resin.

Preferably, the polyimide resin polymer further includes 1-2% of a composite filler, which is nano-magnesia whiskers and nano-silicon oxide at a mass ratio of 1:0-2.

Preferably, the preparation steps of polyimide resin polymer are as follows:

1) Weigh the raw materials according to the weight ratio, slowly heat the polyimide resin to 60-80°C, then add fluorine-containing acrylate copolymer to it, first stir rapidly for 10-15min, then keep warm and stir slowly for 0.5-1h , then lower the temperature to 30±5°C, ultrasonically treat for 10-12min, and then keep it for 2-4h to obtain mixture 1;

2) Add graphene to mixture 1 in batches at room temperature, and keep ultrasonic treatment during the addition process. After the addition is completed, ultrasonic treatment is performed for 20-30 minutes every 15 minutes, and ultrasonic treatment is performed 4-5 times at intervals to obtain mixture 2;

3) Grind the titanium dioxide to the nanometer level, and then add the composite filler into the silica sol under the condition of constant temperature and shaking at 45°C, and keep the reaction for 0.5-1.5h to obtain the mixture 3;

4) Slowly add mixture 3 to mixture 2 under stirring condition, first heat and stir at 45-50° C. for 30 minutes, then lower to room temperature and stir to form a homogeneous phase.

In the preparation method of the above-mentioned graphene composite polyimide film, all the components are fully mixed, and the film layer is prepared by a casting method, and then cooled by two rollers, drawn, and coiled.

Preferably, the thickness of the graphene composite polyimide film is 8-12 μm; the volume resistivity is 4.5×10 ¹ -3.7×10 ⁶ .

Compared with the prior art, the present invention has the following beneficial effects: the graphene composite polyimide polymer structure prepared by the present invention through reasonable component ratio has strong electrical conductivity, stable microscopic network structure, and chemical modification between components Combined, the mechanical properties and electrical properties have been significantly improved. Each component is processed step by step, followed by doping and modification. First, the polyimide resin and fluorine-containing acrylate copolymer are blended and reacted. Transparency and toughness. On the other hand, the super-disproportionated block copolymer significantly improves the spatial network structure of the resin, and has good amphoteric reactivity, which improves the cross-linking and bonding between groups. The layered graphene added later, a part of the surface layer is bonded, and a part of the interior is embedded, which can be combined with strong spatial accommodation, significantly improved dispersion, and good performance improvement. The final filling of nano-titanium dioxide, composite filler and silica sol, on the one hand, improves the mechanical properties, reinforces and strengthens, on the other hand, it can further consolidate the network structure, such as the space between titanium dioxide and polyimide resin that can form a "bridge" Intermolecular bonding and overlapping, silica sol promotes steric rheology, and blends and dilutes with fluorine-containing acrylate copolymers to accelerate the bonding efficiency with the resin matrix.

The graphene composite polyimide film of the present invention has excellent mechanical properties, the elongation at break is greater than 45%, the thickness of the film is only 8-12 μm, the tensile strength at room temperature is greater than 180 MPa, the elastic modulus is greater than 2.88 GPa, and it is wrinkle-free and smooth High density, volume resistivity 4.5×10 ¹ -3.7×10 ⁶ .

Detailed ways

Specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.

Example 1

A graphene composite polyimide film is composed of the following components in parts by weight: 170 parts of polyimide resin polymers, 1.2 parts of fullerenes, 0.13 parts of rare earth oxides, and 2.7 parts of modifiers; The modifying agent is prepared from methyl salicylate and liquid paraffin in a weight ratio of 3.5:1.

The polyimide resin polymer comprises the following components in weight percent: graphene 1%, titanium dioxide 2%, silica sol 0.5%, fluorine-containing acrylate copolymer 4%, polyimide resin balance, as follows Steps to proceed:

1) Weigh the raw materials according to the weight ratio, slowly heat the polyimide resin to 60°C, then add fluorine-containing acrylate copolymer to it, first stir rapidly at 150rpm for 15min, then stir slowly at constant temperature at 50rpm for 0.5h, Then lower the temperature to 30±5°C, ultrasonically treat at 45KHz for 10-12min, and then keep it for 3h to obtain mixture 1;

2) Add graphene to mixture 1 in 5 times under normal temperature conditions, and maintain 28KHz ultrasonic treatment during the addition process. The whole addition process is not less than 20min. 4 times, mixture 2 was obtained;

3) Grind the titanium dioxide to the nanometer level, and then add it together with the composite filler into the silica sol under the condition of constant temperature and shaking at 45°C, and keep it for 1 hour to obtain the mixture 3;

4) Slowly add mixture 3 to mixture 2 under stirring condition, first heat and stir at 50°C for 30 minutes, then lower to room temperature and stir to form a homogeneous phase.

All the components of the graphene composite polyimide film are fully mixed, and the film is prepared by a casting method, and then cooled, drawn, and coiled by two rollers.

The graphene composite polyimide film prepared above has a thickness of 15 μm, a normal temperature tensile strength of 190 MPa, an elongation at break of 46%, an elastic modulus of 2.90 GPa, and is wrinkle-free and has high flatness.

Example 2

A graphene composite polyimide film is composed of the following components in parts by weight: 200 parts of polyimide resin polymers, 1.8 parts of fullerenes, 0.2 parts of rare earth oxides, and 3 parts of modifiers; The modifying agent is prepared from methyl salicylate and liquid paraffin in a weight ratio of 4:1.

The polyimide resin polymer comprises the following components in weight percent: graphene 0.2%, titanium dioxide 1%, silica sol 4%, fluorine-containing acrylate copolymer 3%, polyimide resin balance, also includes The composite filler is 1.5%, and the composite filler is nano-magnesia whisker and nano-silicon oxide with a mass ratio of 1:2. Polyimide resin polymer is carried out according to the following steps:

1) Weigh the raw materials according to the weight ratio, slowly heat the polyimide resin to 80°C, then add fluorine-containing acrylate copolymer to it, first stir rapidly at 150rpm for 15min, then stir slowly at constant temperature at 30rpm for 0.5h, Then lower the temperature to 30±5°C, ultrasonically treat at 48KHz for 10-12min, and then keep it for 4h to obtain mixture 1;

2) Add graphene to mixture 1 in 5 times under normal temperature conditions, and maintain 28KHz ultrasonic treatment during the addition process. The whole addition process is not less than 20min. 5 times, mixture 2 was obtained;

3) Grind the titanium dioxide to the nanometer level, and then add it together with the composite filler into the silica sol under the condition of constant temperature and shaking at 45°C, and keep it for 1 hour to obtain the mixture 3;

4) Slowly add mixture 3 to mixture 2 under stirring condition, first heat and stir at 50°C for 30 minutes, then lower to room temperature and stir to form a homogeneous phase.

All the components of the graphene composite polyimide film are fully mixed, and the film is prepared by a casting method, and then cooled, drawn, and coiled by two rollers.

The graphene composite polyimide film prepared above has a thickness of 12 μm, a normal temperature tensile strength of 202 MPa, an elongation at break of 50%, an elastic modulus of 2.95 GPa, and is wrinkle-free and has high flatness.

Example 3

A graphene composite polyimide film is composed of the following components in parts by weight: 200 parts of polyimide resin polymers, 1.8 parts of fullerenes, 0.2 parts of rare earth oxides, and 3 parts of modifiers; The modifying agent is prepared from methyl salicylate and liquid paraffin in a weight ratio of 4.5:1.

The polyimide resin polymer comprises the following components in percentage by weight: graphene 0.75%, titanium dioxide 3%, silica sol 3%, fluorine-containing acrylate copolymer 6%, polyimide resin balance, also includes The composite filler is 2%, and the composite filler is nano-magnesia whisker and nano-silicon oxide with a mass ratio of 1:1. The preparation method of the polyimide resin polymer is the same as in Example 2.

All the components of the graphene composite polyimide film are fully mixed, and the film is prepared by a casting method, and then cooled, drawn, and coiled by two rollers.

The graphene composite polyimide film prepared above has a thickness of 10 μm, a normal temperature tensile strength of 208 MPa, an elastic modulus of 3.01 GPa, an elongation at break of 52%, and has no wrinkle and high flatness.

The above disclosures are only a few specific embodiments of the present invention, however, the present invention is not limited thereto, and any changes conceivable by those skilled in the art shall fall within the protection scope of the present invention.

Claims (7)

1. a kind of graphene compound polyimide film, it is characterised in that by following components by weight：

Polyimide resin polymer 150-300 parts, fullerene 1-2 parts, rare earth oxide 0.1-0.2 parts, modifying agent 2.5-3.5 Part；

Polyimide resin polymer includes following weight percentage component：Graphene 0.2-1.5%, titanium dioxide 1-5%, silicon Colloidal sol 0.5-6%, fluoro-acrylate copolymer 2-10%, wherein polyimide resin surplus, fluoro-acrylate copolymer For molecular weight 3000-10000 dissaving polymers.

2. a kind of graphene compound polyimide film according to claim 1, it is characterised in that the modifying agent is by water Poplar acid methyl esters and liquid paraffin are according to weight ratio (3-5)：1 proportional arrangement forms.

A kind of 3. graphene compound polyimide film according to claim 1, it is characterised in that the polyimides tree Lipopolymer includes following percentage composition component：Graphene 0.5-0.75%, titanium dioxide 2-3%, Ludox 2-5%, fluorine-containing third Olefin(e) acid ester copolymer 3-6%, polyimide resin surplus.

4. a kind of graphene compound polyimide film according to claim 1, it is characterised in that polyimide resin gathers Compound also includes composite filler 1-2%, and the composite filler is mass ratio 1：It is 0-2 nano magnesia whisker, nano oxidized Silicon.

5. a kind of graphene compound polyimide film according to claim 1, it is characterised in that polyimide resin gathers The preparation process of compound is as follows：

1) raw material is weighed by weight, and polyimide resin slow heating is warming up to 60-80 DEG C, then added thereto fluorine-containing Acrylate copolymer, first quick stirring 10-15mi n, are then incubated and mix slowly 0.5-1h, then are cooled to 30 ± 5 DEG C, surpass Sonication 10-12mi n, then insulation stand 2-4h, obtain mixture one；

2) graphene is added in mixture one in batches under normal temperature condition, keeps being ultrasonically treated in adding procedure, it is to be added After the completion of every 15mi n be ultrasonically treated 20-30mi n, interval be ultrasonically treated 4-5 times, obtain mixture two；

3) titanium dioxide is ground to nanoscale, then adds Ludox under the conditions of 45 DEG C of isothermal vibrations together with composite filler In, insulation reaction 0.5-1.5h, obtain mixture three；

4) mixture three is slowly added in mixture two under agitation, first in 45-50 DEG C of insulated and stirred 30mi n, then Stirring at normal temperature is down into homogeneously.

6. the preparation method of the graphene compound polyimide film described in claim 1-5, it is characterised in that by all components Be sufficiently mixed, film be prepared using the tape casting, then cool down, draw through double roller, batch it is obtained.

7. preparation method according to claim 6, it is characterised in that the graphene compound polyimide film thickness is 8-12μm；Specific insulation is 4.5 × 10¹-3.7×10⁶。