A kind of flexibility high thermal conductivity graphene compound polyimide film and preparation method thereof
Technical field
The invention belongs to polymer composites technical field more particularly to a kind of compound polyamides of flexible high thermal conductivity graphene
Imines film and preparation method thereof.
Background technique
Possess stable aromatic heterocyclic structure in the strand of polyimide film, makes it have excellent resistance to oxidation and high temperature resistant
Performance and the characteristics such as excellent mechanical performance and carbon density height.In view of the various advantages of its own, polyimide film is wide
It is applied to electronic field as temperature-resistant material generally.With micromation, the development of precise treatment technology, exist to properties of product and product
Heat conductivity and requirement flexible under various environment are continuously improved, it is therefore desirable to the heat conductivity of polyimide film be continuously improved
It can and improve its flexibility.
The general manufacturing method of polyimide film is to synthesize its preceding aggressiveness polyamic acid using solution polycondensation method at present
(PAA), then polyamic acid constant-pressure and high-temperature is handled again, is allowed to dehydration closed-loop imidization, polyimide film is made;Or it is inciting somebody to action
Temperature is maintained in -5 DEG C of polyamic acid solutions below and a certain amount of dehydrating agent and catalyst is added, and is heated to certain temperature and is allowed to de-
Water closed loop imidization, is made film.Although the polyimide film that this method prepares is up to the purity of electron level, its hot ruler
Very little stability is poor, thermal stability is low.And often the surface folding of autoclaving formation can cause thermal coefficient to be greatly reduced
The brittleness for increasing material simultaneously, keeps polyimide film not resistant to bending.
Summary of the invention
Based on this, the present invention provides a kind of flexible high thermal conductivity graphene compound polyimide film and preparation method thereof, utilizes
The graphene compound polyimide film with good heating conduction and toughness can be made in the preparation method.
The preparation method of flexibility high thermal conductivity graphene compound polyimide film of the present invention the following steps are included:
S1: in 0.005MPa vacuum environment below, polyimides colloid is placed in carbonaceous gas and argon plasma
In mixture, reaction obtains graphene compound polyimide presoma under 40~450 DEG C and catalyst action;
S2: the graphene compound polyimide presoma is placed in the vacuum environment of 0.0002~0.0001MPa,
Heat treatment obtains graphene compound polyimide film at 100~300 DEG C.
Compared with the existing technology, preparation method of the invention uses plasma auxiliary chemical vapor deposition method, makes carbon containing
Gas decomposes and is directly nucleated and assembles in situ in gelatinous polyimides graphene, forms graphene compound polyimide
Resin precursor;Then make the full imidization of polyimides through decompression heating, being formed has graphene compound polyimide flexible
Film.There are imino groups abundant for the polyimides colloid of part imidization, and carbonaceous gas resolves into carbon simultaneously in high vacuum conditions
Nucleation forms graphene centered on active imino group, makes to constitute extremely strong covalent bond between graphene and polyimides,
Interface resistance is greatly reduced, improves the heating conduction and toughness of film.
Further, the polyimides colloid imidization degree is 30~40%.
Further, the preparation method of the polyimides colloid is that dianhydride and diamines are distributed to aprotic polar solvent
In, polycondensation generates polyamic acid solution under -10~10 DEG C of constant temperatures;Then use chemical imines method by polyamic acid solution
The polyimides colloid that imidization degree is 30~40% is made in imidization.
Further, acetic anhydride/pyrrole is added specifically, at 40~50 DEG C in the chemical imines method in polyamic acid solution
Pyridine mixture reacts to obtain the polyimides colloid that imidization degree is 30~40%, wherein polyamic acid solution and acetic anhydride/
Pyridine mixtures volume ratio is 2:1~4:1.
Further, the ratio of the dianhydride, diamines and aprotic polar solvent is 1mg:1mg:(3~10) ml.
Further, the dianhydride is pyromellitic acid anhydride, and the diamines is 4,4 '-diaminodiphenyl ethers, the non-matter
Sub- polar solvent is tetrahydrofuran.
Further, the carbonaceous gas is one of methane, ethylene and ethyl alcohol, and purity is greater than 99.99%.
Further, the catalyst is copper.
Flexibility high thermal conductivity graphene compound polyimide film provided by the present invention includes polyimides and graphene, described
Polyimides is with graphene by being covalently keyed.
Compared with the existing technology, graphene compound polyimide film of the invention is auxiliary heat eliminating medium, stone with graphene
Black alkene, by being covalently keyed, using high thermal conductivity possessed by graphene itself and flexibility, significantly improves stone with polyimides
The heating conduction and toughness of black alkene compound polyimide film.
Further, the polyimides weight ratio is 90~95wt%, and the graphene weight ratio is 5~10wt%;Institute
State graphene in the form of sheets, with a thickness of 0.5~2nm, piece diameter is 0.1~3 μm.
Specific embodiment
The present invention utilizes plasma auxiliary chemical vapor deposition method, in situ on the polyimides gel of part imidization
Graphene is formed, by being auxiliary heat eliminating medium with graphene, interface resistance is greatly reduced, improves heating conduction, improves simultaneously
Toughness.Illustrate technical solution of the present invention below by way of specific embodiment.
Embodiment 1
Flexibility high thermal conductivity graphene compound polyimide film of the present invention is prepared by following steps:
S1: in 0.005MPa vacuum environment below, polyimides colloid is placed in carbonaceous gas and argon plasma
In mixture, reaction obtains graphene compound polyimide presoma under 40~450 DEG C and catalyst action;
S2: the graphene compound polyimide presoma is placed in the vacuum environment of 0.0002~0.0001MPa,
Heat treatment obtains graphene compound polyimide film at 100~300 DEG C.
Specifically, pyromellitic acid anhydride and 4 are weighed first, and 4 '-diaminodiphenyl ethers are packed into round bottom there-necked flask, by every
The ratio that 10mg pyromellitic acid anhydride, 10mg 4,4 '-diaminodiphenyl ether convert 30ml tetrahydrofuran makes after tetrahydrofuran is added
Disperse 0.5h with ultrasonic echography, pyromellitic acid anhydride and 4,4 '-diaminodiphenyl ethers are then made under -3 DEG C of constant temperatures
Polyamic acid (PAA) solution of polycondensation generation high molecular weight.Then be added acetic anhydride/pyridine (polyamic acid solution and acetic anhydride/
Pyridine volume ratio is 2:1~4:1), so that the imidization of polyamic acid part is obtained imidization degree 30 under the conditions of 40~50 DEG C
~40% polyimides colloid.
It is to account for it in the shaggy copper mold of 5cm by the polyimides colloid filling radius of part imidization
2/3rds of full mould volume, are then placed in tube furnace.Then methane gas and argon that purity is greater than 99.99% are passed through
Argon gas is excited into argon plasma by gas, and controls initial depression in 0.003MPa or less, gas flow rate 0.3ml/min,
Temperature is warming up to 450 DEG C from 40 DEG C of rate programs with 4 DEG C/min simultaneously, wherein keeping after every 50 DEG C of raising before 200 DEG C
30min, after 200 DEG C it is every increase 30 DEG C after keep 1.5h.Air pressure is restored normal by cooled to room temperature after the completion of temperature programming
Pressure, obtains graphene compound polyimide resin precursor.
Vacuum degree in tube furnace is gradually reduced to 0.0006MPa, then with the rate of 30 DEG C/min by temperature from 100
DEG C temperature programming is to 260 DEG C.Constant temperature pressure maintaining 20min after being wherein increased to 180 DEG C;Constant temperature pressure maintaining 100min after being increased to 260 DEG C.
Natural cooling after the completion of temperature programming.When temperature is down to 50 DEG C, film is unloaded, obtains graphene compound polyimide film.
Through detecting, using the above method preparation graphene compound polyimide film in contain 90~95wt% polyimides
With 5~10wt% graphene weight.Wherein in the form of sheets, with a thickness of 0.5~2nm, piece diameter is 0.1~3 μm to graphene.
Using laser lightning method heat transfer analysis instrument and universal testing machine to prepared graphene compound polyimide
The heating conduction of film is measured with mechanical property, measure the graphene compound polyimide film stretching intensity be 150.5Mpa,
Young's modulus is 1.55Gpa, thermal coefficient is 1860W/m.K in the face at 30 DEG C.
Embodiment 2
Flexibility high thermal conductivity graphene compound polyimide film of the present invention is prepared by following steps:
S1: in 0.005MPa vacuum environment below, polyimides colloid is placed in carbonaceous gas and argon plasma
In mixture, reaction obtains graphene compound polyimide presoma under 40~450 DEG C and catalyst action;
S2: the graphene compound polyimide presoma is placed in the vacuum environment of 0.0002~0.0001MPa,
Heat treatment obtains graphene compound polyimide film at 100~300 DEG C.
Specifically, pyromellitic acid anhydride and 4 are weighed first, and 4 '-diaminodiphenyl ethers are packed into round bottom there-necked flask, by every
After tetrahydrofuran is added in the ratio that 10mg pyromellitic acid anhydride, 10mg 4,4 '-diaminodiphenyl ether convert 100ml tetrahydrofuran
Disperse 1h using ultrasonic echography, pyromellitic acid anhydride and 4,4 '-diaminodiphenyl ethers are then made under -10 DEG C of constant temperatures
Polyamic acid (PAA) solution of polycondensation generation high molecular weight.Then be added acetic anhydride/pyridine (polyamic acid solution and acetic anhydride/
Pyridine volume ratio is 2:1~4:1), so that the imidization of polyamic acid part is obtained imidization degree 30 under the conditions of 40~50 DEG C
~40% polyimides colloid.
It is to account for it in the shaggy copper mold of 10cm by the polyimides colloid filling radius of part imidization
3/4ths of full mould volume, are then placed in tube furnace.Then ethylene gas and argon that purity is greater than 99.99% are passed through
Argon gas is excited into argon plasma by gas, and controls initial depression in 0.005MPa or less, gas flow rate 0.1ml/min,
Temperature is warming up to 450 DEG C from 40 DEG C of rate programs with 5 DEG C/min simultaneously, wherein keeping after every 50 DEG C of raising before 200 DEG C
40min, after 200 DEG C it is every increase 30 DEG C after keep 1.5h.Air pressure is restored normal by cooled to room temperature after the completion of temperature programming
Pressure, obtains graphene compound polyimide resin precursor.
Vacuum degree in tube furnace is gradually reduced to 0.0002MPa, then with the rate of 30 DEG C/min by temperature from 100
DEG C temperature programming is to 300 DEG C.Constant temperature pressure maintaining 30min after being wherein increased to 200 DEG C;Constant temperature pressure maintaining 120min after being increased to 300 DEG C.
Natural cooling after the completion of temperature programming.When temperature is down to 80 DEG C, film is unloaded, obtains graphene compound polyimide film.
Through detecting, using the above method preparation graphene compound polyimide film in contain 90~95wt% polyimides
With 5~10wt% graphene weight.Wherein in the form of sheets, with a thickness of 0.5~2nm, piece diameter is 0.1~3 μm to graphene.
Using laser lightning method heat transfer analysis instrument and universal testing machine to prepared graphene compound polyimide
The heating conduction of film is measured with mechanical property, measure the graphene compound polyimide film stretching intensity be 155.8Mpa,
Young's modulus is 1.60Gpa, thermal coefficient is 1900W/m.K in the face at 30 DEG C.
Embodiment 3
Flexibility high thermal conductivity graphene compound polyimide film of the present invention is prepared by following steps:
S1: in 0.005MPa vacuum environment below, polyimides colloid is placed in carbonaceous gas and argon plasma
In mixture, reaction obtains graphene compound polyimide presoma under 40~450 DEG C and catalyst action;
S2: the graphene compound polyimide presoma is placed in the vacuum environment of 0.0002~0.0001MPa,
Heat treatment obtains graphene compound polyimide film at 100~300 DEG C.
Specifically, pyromellitic acid anhydride and 4 are weighed first, and 4 '-diaminodiphenyl ethers are packed into round bottom there-necked flask, by every
The ratio that 10mg pyromellitic acid anhydride, 10mg 4,4 '-diaminodiphenyl ether convert 60ml tetrahydrofuran makes after tetrahydrofuran is added
Disperse 0.8h with ultrasonic echography, pyromellitic acid anhydride and 4, the contracting of 4 '-diaminodiphenyl ethers are then made under 0 DEG C of constant temperature
Consor at high molecular weight polyamic acid (PAA) solution.Then acetic anhydride/pyridine (polyamic acid solution and acetic anhydride/pyrrole is added
Pyridine volume ratio is 2:1~4:1), make under the conditions of 40~50 DEG C the imidization of polyamic acid part obtain imidization degree 30~
40% polyimides colloid.
It is to account for it in the shaggy copper mold of 8cm by the polyimides colloid filling radius of part imidization
The half of full mould volume, is then placed in tube furnace.Then alcohol gas and argon that purity is greater than 99.99% are passed through
Argon gas is excited into argon plasma by gas, and controls initial depression in 0.005MPa or less, gas flow rate 0.5ml/min,
Temperature is warming up to 450 DEG C from 40 DEG C of rate programs with 4 DEG C/min simultaneously, wherein keeping after every 50 DEG C of raising before 200 DEG C
35min, after 200 DEG C it is every increase 30 DEG C after keep 1.2h.Air pressure is restored normal by cooled to room temperature after the completion of temperature programming
Pressure, obtains graphene compound polyimide resin precursor.
Vacuum degree in tube furnace is gradually reduced to 0.0006MPa, then with the rate of 30 DEG C/min by temperature from 100
DEG C temperature programming is to 250 DEG C.Constant temperature pressure maintaining 25min after being wherein increased to 150 DEG C;Constant temperature pressure maintaining 110min after being increased to 250 DEG C.
Natural cooling after the completion of temperature programming.When temperature is down to 50 DEG C, film is unloaded, obtains graphene compound polyimide film.
Through detecting, using the above method preparation graphene compound polyimide film in contain 90~95wt% polyimides
With 5~10wt% graphene weight.Wherein in the form of sheets, with a thickness of 0.5~2nm, piece diameter is 0.1~3 μm to graphene.
Using laser lightning method heat transfer analysis instrument and universal testing machine to prepared graphene compound polyimide
The heating conduction of film is measured with mechanical property, measure the graphene compound polyimide film stretching intensity be 165.3Mpa,
Young's modulus is 1.58Gpa, thermal coefficient is 1880W/m.K in the face at 30 DEG C.
Compared with the existing technology, the present invention uses plasma auxiliary chemical vapor deposition method, resolves into carbonaceous gas
Atomic state carbon, and under the catalytic action at copper-based bottom, the carbon of atomic state is directly in the polyimides of gelatinous part imidization
Middle original position is nucleated and assembles graphene, forms graphene compound polyimide resin precursor;Then make polyamides through decompression heating
The full imidization of imines, forming graphene is auxiliary heat eliminating medium with graphene compound polyimide film flexible.Part is sub-
There are imino groups abundant for the polyimides colloid of amination, and carbonaceous gas resolves into carbon and with active in high vacuum conditions
Nucleation forms graphene centered on imino group, makes to constitute extremely strong covalent bond between graphene and polyimides, boundary is greatly reduced
Face thermal resistance makes the thermal coefficient of film be increased to 1860W/m.K or more, while the toughness of film is effectively improved.
The embodiments described above only express several embodiments of the present invention, and the description thereof is more specific and detailed, but simultaneously
It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art
It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to protection of the invention
Range.