A kind of preparation of Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials
Method
Technical field
The invention belongs to insulating materials field, it is related to a kind of preparation method of epoxy composite insulating materials, and in particular to one
Plant the preparation method of Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials.
Background technology
Epoxy resin is a kind of with outstanding mechanics, the thermosetting resin of insulating properties, is widely used in coating, bonding
The fields such as agent, electronic material encapsulation and electrical equipment and electrical.In terms of power equipment GIS, epoxide resin material is widely used as high pressure
Conductor insulation backing material, the performance such as this heat endurance, mechanical performance, alternating current breakdown characteri to epoxy composite material is proposed
It is higher and higher to require.Using addition micron Al more than traditional GIS device2O3Or micron SiO2The epoxy resin of filler is combined
Insulating materials, but its disruptive field intensity has larger reduction compared with pure epoxy resin.In recent years, nano composite material is compound compared to micron
Material, the inorganic filler that epoxy composite material in more excellent performance, GIS is shown in terms of electric property considers to add nanometer
Al2O3And SiO2Particle is modified.However, nano-particle is because specific surface area is big, apparent activation energy is high, reunion is also easy to produce existing
As what is especially showed under high filler content is the most obvious.Secondly, if nothing between inorganic nano-particle and organic epoxy radical body
Chemical bond, boundary strength is weak, causes composite insulating material system to there is larger defect.Therefore, in order to improve nano-particle
Dispersiveness and strengthen the interface bond strength of compound system to a certain extent, it is necessary to study novel nano epoxy resin multiple
The preparation of condensation material and performance are improved.
The content of the invention
It is an object of the invention to provide a kind of Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials
Preparation method, this method passes through to nanometer Al2O3The modification of particle, makes a nanometer Al2O3Can between particle and epoxy resin-base
The effect of chemical bond is directly produced, so as to improve the combination property of whole epoxy composite insulating materials.
To reach above-mentioned purpose, the technical solution adopted by the present invention is:
A kind of preparation method of Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials, including following step
Suddenly:
1) Nano filling Al2O3Surface coupling processing
By nanometer α-Al2O3Particle and silane coupler are added in ethanol, 3~5h of heating stirring at 70~90 DEG C, then
Washing, standing, vacuum drying, obtain introducing the coupling modifier powder of silicon oxygen bond;Wherein every 2~8g nanometers of α-Al2O3Particle adds
Enter into 100~400mL ethanol, silane coupler and nanometer α-Al2O3The mass ratio of particle is 1:1;
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By step 1) obtained coupling modifier powder and initiator be added to the water, stir, then add acrylamide
Monomer, in 40~60 DEG C of 2.5~4h of stirring reaction, is washed out, stands, is dried in vacuo, and obtaining surface grafting has silicon oxygen bond, carbon
The nanometer Al of carbon double bond and amino2O3Modified powder;Wherein every 2~4g coupling modifiers powder is added in 100~200mL water, plus
The mass ratio of the coupling modifier powder, initiator and the acrylamide monomer that enter is 2:(0.07~0.18):3.5;
3) modified Nano Al2O3Particle in the epoxy scattered
Acid anhydride type curing agent and step 2 are added into epoxy resin) obtained surface grafting have silicon oxygen bond, carbon-carbon double bond and
The nanometer Al of amino2O3Modified powder, it is ultrasonic in 0 DEG C of ice bath after being uniformly dispersed, accelerator is then added, disperses equal again
Suspension is obtained after even;The surface grafting wherein added has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder
Quality is the 1~5% of suspension quality, and the quality of acid anhydride type curing agent is the 80~86% of epoxy resin quality, accelerator
Quality is the 1~2% of epoxy resin quality;
4) preparation of epoxy composite insulating materials
By step 3) obtained suspension is put into vacuum drying chamber, carries out first time vacuum outgas, and then will be after degassing
Suspension be poured into the mould for scribbling releasing agent, then mould be put into vacuum drying chamber carry out second of vacuum outgas,
Finally solidified, solidification process in two steps, solidifies 2~4h first at 100~120 DEG C, it is then solid at 120~150 DEG C
Change 12~16h, cool down, be stripped after the completion of solidification, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulation material
Material.
The step 1) in ethanol volume fraction be 90~95%;Mixing speed is 250~400r/min;Cleaning solvent
For absolute ethyl alcohol.
The step 1) in time of repose be 12~20h;Vacuum drying be 70~100 DEG C temperature and be less than
20~36h is dried under 133Pa pressure.
The step 2) in initiator be ammonium persulfate and sodium hydrogensulfite, and the matter of ammonium persulfate and sodium hydrogensulfite
Amount is than being (3~1):1.
The step 2) in stir be in 40~60 DEG C of 0.5~1h of stirring reaction;Mixing speed be 250~
500r/min;Cleaning solvent is water.
The step 2) in time of repose be 40~48h;Vacuum drying is in the temperature less than -80 DEG C and less than 50Pa
Pressure under dry 24~96h.
The silane coupler is γ-methacryloxypropyl trimethoxy silane (trade mark is KH570), asphalt mixtures modified by epoxy resin
Fat is bisphenol A-type glycidyl ether type epoxy resin, and acid anhydride type curing agent is methyl tetrahydro phthalic anhydride, and accelerator is dimethylbenzyl
Amine.
The step 3) in be uniformly dispersed specifically with rotation-revolution mixer first 500~1000r/min rotating speed
10~15min of lower rotation, then 5~10min of rotation under 1000~2000r/min rotating speed.
The step 3) in ultrasonic power be 400~600W, each ultrasonic time be 1~2s, ultrasonic gap be 1~
2s, whole ultrasonic procedure continues 30~60min.
The step 4) in first time vacuum outgas when temperature be 40~60 DEG C, pressure be less than 133Pa, the time is 30
~60min;Temperature during second of vacuum outgas is 60~80 DEG C, and pressure is that, less than 133Pa, the time is 60~120min.
Relative to prior art, beneficial effects of the present invention are:
The preparation method for the Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials that the present invention is provided, can
Overcome the influence to epoxy resin electric property produced by micro-and nano-particles are reunited in the prior art, this method is with epoxy resin
For matrix, with the good nanometer Al of combination property2O3For filler, using silane coupler to nanometer Al2O3It is even that filler carries out surface
Connection processing, in Al2O3Surface is introduced into carbon carbon unsaturated double-bond contained in silane coupler, with the carbon carbon unsaturated double-bond of introducing
Occurs sudden reaction as the carbon carbon unsaturated double-bond in fulcrum, with acrylamide monomer, so that in nanometer Al2O3Surface is introduced
Crosslinking similar to amine curing agent can occur with epoxy resin for contained characteristic group's amino in acrylamide monomer, the amino
Curing reaction, makes a nanometer Al2O3The effect of chemical bond is directly produced between particle and epoxy resin-base, strengthens whole epoxy and answers
Close the boundary strength of insulating materials.Nanometer Al2O3Particle is after coupling modifier and Modified by Acrylamide Graft, in asphalt mixtures modified by epoxy resin
It is uniformly dispersed and is combined closely with epoxy resin-base in aliphatic radical body.The Modified by Acrylamide Graft nanometer according to made from this method
Aluminum oxide epoxy composite insulating material has good heat endurance, breakdown performance and dielectric properties, and it thermally decomposes initial temperature
Higher than traditional micron Al2O3/ epoxy resin composite material, remaining rate when decomposing completely is higher than traditional micron Al2O3/ ring
Epoxy resin composite material, AC breakdown strength is higher than traditional micron Al2O3/ epoxy resin composite material, real part of permittivity value
Higher than pure epoxy resin, and HFS (>Dielectric loss 100Hz) is less than pure epoxy resin.
Brief description of the drawings
Fig. 1 is Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials made from the embodiment of the present invention 3
SEM sectional drawings;
Fig. 2 be before modified after nanometer Al2O3Fourier's infrared analysis collection of illustrative plates of powder;
Fig. 3 is the Weibull distribution figure of the AC breakdown strength of composite insulating material;
Fig. 4 is the TGA thermal gravimetric analysis curve figures of composite insulating material;
Fig. 5 is the broadband dielectric spectroscopy real part of permittivity figure of composite insulating material;
Fig. 6 is the broadband dielectric spectroscopy loss angle tangent figure of composite insulating material;
Wherein, BER represents pure epoxy resin in Fig. 3-6, and MC represents to fill a micron Al in the epoxy2O3(account for insulation material
The 65wt% of material) obtained epoxy composite insulating materials, NC1~NC3 represents propylene made from the embodiment of the present invention 1~3 respectively
Acid amide-grafted modified nano-alumina epoxy composite insulating materials.
Embodiment
The present invention is described in further details below in conjunction with the accompanying drawings.
Embodiment 1
1) Nano filling Al2O3Surface coupling processing
By 2g nanometers of α-Al2O3Particle and 2g silane couplers KH570 are added to the ethanol that 100mL volume fractions are 95%
In, 4h is stirred with 300r/min rotating speed with magnetic agitation heating instrument at 80 DEG C.Then with 10000r/min centrifugation
5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand under 16h, then the temperature at 80 DEG C and the pressure less than 133Pa
24h is dried in vacuo, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 2g steps 1) obtained coupling modifier powder is added in 100mL deionized waters, adds initiator persulfuric acid
Ammonium and sodium hydrogensulfite, in 50 DEG C of speed magnetic agitation 0.5h with 300r/min, then add acrylamide monomer, at 50 DEG C
3h is reacted with 300r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min's
Centrifugation 5min, multiple centrifuge washing stands 48h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa very
Sky dries 24h, and obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling modifier
The mass ratio of powder, initiator and acrylamide monomer is 2:0.09:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite is
2:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 10min is first rotated under 1000r/min rotating speed, then in 2000r/min rotating speed
Lower rotation 5min, obtains mixed liquor.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
45min, wherein, ultrasonic time 1s, ultrasonic gap 1s, ultrasonic power is 500W.Accelerator dimethyl benzylamine is added after ultrasound is complete
(BDMA) 10min, then turning in 2000r/min first, are rotated under 1000r/min rotating speed with rotation-revolution mixer afterwards
The lower rotation 5min of speed.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface grafting wherein added has
The nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 1% of suspension quality, acid anhydride type curing agent
Quality is the 86% of bisphenol A-type glycidyl ether type epoxy resin quality, and the quality of accelerator is bisphenol A-type glycidol ethers
The 1% of epoxy resin quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 50 DEG C, pressure be less than 133Pa,
Vacuum outgas 60min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 60 DEG C of temperature
And continue vacuum outgas 60min under the pressure less than 133Pa.Finally solidified:First solidify 2h at 120 DEG C, then at 150 DEG C
Lower solidification 12h.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials after having solidified,
Specially 1wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 2
1) Nano filling Al2O3Surface coupling processing
By 2g nanometers of α-Al2O3Particle and 2g silane couplers KH570 are added to the ethanol that 100mL volume fractions are 95%
In, 4h is stirred with 300r/min rotating speed with magnetic agitation heating instrument at 80 DEG C.Then with 10000r/min centrifugation
5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand under 16h, then the temperature at 80 DEG C and the pressure less than 133Pa
24h is dried in vacuo, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 2g steps 1) obtained coupling modifier powder is added in 100mL deionized waters, adds initiator persulfuric acid
Ammonium and sodium hydrogensulfite, in 50 DEG C of speed magnetic agitation 0.5h with 300r/min, then add acrylamide monomer, at 50 DEG C
3h is reacted with 300r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min's
Centrifugation 5min, multiple centrifuge washing stands 48h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa very
Sky dries 24h, and obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling modifier
The mass ratio of powder, initiator and acrylamide monomer is 2:0.09:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite is
2:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 10min is first rotated under 1000r/min rotating speed, then in 2000r/min rotating speed
Lower rotation 5min, obtains mixed liquor.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
45min, wherein, ultrasonic time 1s, ultrasonic gap 1s, ultrasonic power is 500W.Accelerator dimethyl benzylamine is added after ultrasound is complete
(BDMA) 10min, then turning in 2000r/min first, are rotated under 1000r/min rotating speed with rotation-revolution mixer afterwards
The lower rotation 5min of speed.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface grafting wherein added has
The nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 3% of suspension quality, acid anhydride type curing agent
Quality is the 86% of bisphenol A-type glycidyl ether type epoxy resin quality, and the quality of accelerator is bisphenol A-type glycidol ethers
The 1% of epoxy resin quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 50 DEG C, pressure be less than 133Pa,
Vacuum outgas 60min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 60 DEG C of temperature
And continue vacuum outgas 60min under the pressure less than 133Pa.Finally solidified:First solidify 2h at 120 DEG C, then at 150 DEG C
Lower solidification 12h.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials after having solidified,
Specially 3wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 3
1) Nano filling Al2O3Surface coupling processing
By 2g nanometers of α-Al2O3Particle and 2g silane couplers KH570 are added to the ethanol that 100mL volume fractions are 95%
In, 4h is stirred with 300r/min rotating speed with magnetic agitation heating instrument at 80 DEG C.Then with 10000r/min centrifugation
5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand under 16h, then the temperature at 80 DEG C and the pressure less than 133Pa
24h is dried in vacuo, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 2g steps 1) obtained coupling modifier powder is added in 100mL deionized waters, adds initiator persulfuric acid
Ammonium and sodium hydrogensulfite, in 50 DEG C of speed magnetic agitation 0.5h with 300r/min, then add acrylamide monomer, at 50 DEG C
3h is reacted with 300r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min's
Centrifugation 5min, multiple centrifuge washing stands 48h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa very
Sky dries 24h, and obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling modifier
The mass ratio of powder, initiator and acrylamide monomer is 2:0.09:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite is
2:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 10min is first rotated under 1000r/min rotating speed, then in 2000r/min rotating speed
Lower rotation 5min, obtains mixed liquor.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
45min, wherein, ultrasonic time 1s, ultrasonic gap 1s, ultrasonic power is 500W.Accelerator dimethyl benzylamine is added after ultrasound is complete
(BDMA) 10min, then turning in 2000r/min first, are rotated under 1000r/min rotating speed with rotation-revolution mixer afterwards
The lower rotation 5min of speed.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface grafting wherein added has
The nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 5% of suspension quality, acid anhydride type curing agent
Quality is the 86% of bisphenol A-type glycidyl ether type epoxy resin quality, and the quality of accelerator is bisphenol A-type glycidol ethers
The 1% of epoxy resin quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 50 DEG C, pressure be less than 133Pa,
Vacuum outgas 60min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 60 DEG C of temperature
And continue vacuum outgas 60min under the pressure less than 133Pa.Finally solidified:First solidify 2h at 120 DEG C, then at 150 DEG C
Lower solidification 12h.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials after having solidified,
Specially 5wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 4
1) Nano filling Al2O3Surface coupling processing
By 8g nanometers of α-Al2O3Particle and 8g silane couplers KH570 are added to the ethanol that 400mL volume fractions are 90%
In, 5h is stirred with 400r/min rotating speed with magnetic agitation heating instrument at 70 DEG C.Then with 10000r/min centrifugation
5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand under 12h, then the temperature at 70 DEG C and the pressure less than 133Pa
36h is dried in vacuo, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 4g steps 1) obtained coupling modifier powder is added in 200mL deionized waters, adds initiator persulfuric acid
Ammonium and sodium hydrogensulfite, in 60 DEG C of speed magnetic agitation 0.6h with 250r/min, then add acrylamide monomer, at 40 DEG C
2.5h is reacted with 500r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min
Centrifugation 5min, multiple centrifuge washing stands 40h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa
96h is dried in vacuo, obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling changes
Property powder, initiator and acrylamide monomer mass ratio be 2:0.07:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite
For 3:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 15min is first rotated under 500r/min rotating speed, then under 1000r/min rotating speed
10min is rotated, mixed liquor is obtained.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
30min, wherein, ultrasonic time 1s, ultrasonic gap 1s, ultrasonic power is 600W.Accelerator dimethyl benzylamine is added after ultrasound is complete
(BDMA) 15min, then turning in 1000r/min first, are rotated under 500r/min rotating speed with rotation-revolution mixer afterwards
The lower rotation 10min of speed.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface grafting wherein added has
The nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 3.5% of suspension quality, acid anhydride type curing agent
Quality be the 80% of bisphenol A-type glycidyl ether type epoxy resin quality, the quality of accelerator is bisphenol A-type glycidol ether
The 2% of based epoxy resin quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 40 DEG C, pressure be less than 133Pa,
Vacuum outgas 50min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 80 DEG C of temperature
And continue vacuum outgas 70min under the pressure less than 133Pa.Finally solidified:First solidify 4h at 100 DEG C, then at 120 DEG C
Lower solidification 16h.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials after having solidified,
Specially 3.5wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 5
1) Nano filling Al2O3Surface coupling processing
By 4g nanometers of α-Al2O3Particle and 4g silane couplers KH570 are added to the ethanol that 200mL volume fractions are 92%
In, 3h is stirred with 250r/min rotating speed with magnetic agitation heating instrument at 90 DEG C.Then with 10000r/min centrifugation
5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand 20h, then the temperature at 100 DEG C and the pressure less than 133Pa
Lower vacuum drying 20h, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 3g steps 1) obtained coupling modifier powder is added in 150mL deionized waters, adds initiator persulfuric acid
Ammonium and sodium hydrogensulfite, in 40 DEG C of speed magnetic agitation 0.7h with 500r/min, then add acrylamide monomer, at 60 DEG C
4h is reacted with 250r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min's
Centrifugation 5min, multiple centrifuge washing stands 42h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa very
Sky dries 72h, and obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling modifier
The mass ratio of powder, initiator and acrylamide monomer is 2:0.18:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite is
1:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 11min is first rotated under 900r/min rotating speed, then under 1800r/min rotating speed
6min is rotated, mixed liquor is obtained.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
60min, wherein, ultrasonic time 2s, ultrasonic gap 2s, ultrasonic power is 400W.Accelerator dimethyl benzylamine is added after ultrasound is complete
(BDMA) 11min, then turning in 1800r/min first, are rotated under 900r/min rotating speed with rotation-revolution mixer afterwards
The lower rotation 6min of speed.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface grafting wherein added has
The nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 2.5% of suspension quality, acid anhydride type curing agent
Quality be the 82% of bisphenol A-type glycidyl ether type epoxy resin quality, the quality of accelerator is bisphenol A-type glycidol ether
The 1.5% of based epoxy resin quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 45 DEG C, pressure be less than 133Pa,
Vacuum outgas 45min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 70 DEG C of temperature
And continue vacuum outgas 90min under the pressure less than 133Pa.Finally solidified:First solidify 3h at 110 DEG C, then at 130 DEG C
Lower solidification 15h.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials after having solidified,
Specially 2.5wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 6
1) Nano filling Al2O3Surface coupling processing
By 6g nanometers of α-Al2O3Particle and 6g silane couplers KH570 are added to the ethanol that 300mL volume fractions are 93%
In, 3.5h is stirred with 350r/min rotating speed with magnetic agitation heating instrument at 75 DEG C.Then with 10000r/min speed from
Heart 5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand 14h, then the temperature at 90 DEG C and the pressure less than 133Pa
Lower vacuum drying 22h, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 2.5g steps 1) obtained coupling modifier powder is added in 120mL deionized waters, adds initiator over cure
Sour ammonium and sodium hydrogensulfite, in 45 DEG C of speed magnetic agitation 0.8h with 400r/min, then add acrylamide monomer, 45
DEG C 3.5h is reacted with 400r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/
Min centrifugation 5min, multiple centrifuge washing stands 44h afterwards, then in the temperature less than -80 DEG C and the pressure less than 50Pa
48h is dried in vacuo under power, obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.It is wherein even
The mass ratio for joining modified powder, initiator and acrylamide monomer is 2:0.15:3.5, the matter of ammonium persulfate and sodium hydrogensulfite
Amount is than being 1.5:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 12min is first rotated under 800r/min rotating speed, then under 1500r/min rotating speed
7min is rotated, mixed liquor is obtained.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
40min, wherein, ultrasonic time 1.5s, ultrasonic gap 1.5s, ultrasonic power is 550W.Accelerator dimethyl is added after ultrasound is complete
Benzylamine (BDMA), first rotates 12min with rotation-revolution mixer under 800r/min rotating speed afterwards, then in 1500r/min
Rotating speed under rotate 7min.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface wherein added connects
Branch has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 2% of suspension quality, anhydrides solidification
The quality of agent is the 84% of bisphenol A-type glycidyl ether type epoxy resin quality, and the quality of accelerator is bisphenol A-type glycidol
The 1.2% of ether type epoxy resins quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 55 DEG C, pressure be less than 133Pa,
Vacuum outgas 40min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 65 DEG C of temperature
And continue vacuum outgas 120min under the pressure less than 133Pa.Finally solidified:First solidify 3.5h at 105 DEG C, then
Solidify 14h at 135 DEG C.Cooling, the demoulding after having solidified, that is, obtain the insulation of Modified by Acrylamide Graft nano aluminium oxide epoxy composite
Material, specially 2wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Embodiment 7
1) Nano filling Al2O3Surface coupling processing
By 5g nanometers of α-Al2O3Particle and 5g silane couplers KH570 are added to the ethanol that 250mL volume fractions are 95%
In, 4.5h is stirred with 280r/min rotating speed with magnetic agitation heating instrument at 85 DEG C.Then with 10000r/min speed from
Heart 5min, it is repeated multiple times to use absolute ethyl alcohol centrifuge washing, then stand 18h, then the temperature at 85 DEG C and the pressure less than 133Pa
Lower vacuum drying 30h, obtains introducing the coupling modifier powder of silicon oxygen bond.
2) Nano filling Al2O3The modification of surface grafting acrylamide monomer
By 3.5g steps 1) obtained coupling modifier powder is added in 180mL deionized waters, adds initiator over cure
Sour ammonium and sodium hydrogensulfite, in 55 DEG C of speed magnetic agitation 1h with 280r/min, then add acrylamide monomer, at 55 DEG C
3h is reacted with 280r/min speed magnetic agitation.Then with deionized water as cleaning solvent, every time with 10000r/min's
Centrifugation 5min, multiple centrifuge washing stands 46h afterwards, then at the temperature less than -80 DEG C and the pressure less than 50Pa very
Sky dries 60h, and obtaining surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder.Wherein coupling modifier
The mass ratio of powder, initiator and acrylamide monomer is 2:0.12:3.5, the mass ratio of ammonium persulfate and sodium hydrogensulfite is
2.5:1;
3) the nanometer Al into epoxy resin after disperse modified2O3Particle
Into bisphenol A-type glycidyl ether type epoxy resin add acid anhydride type curing agent methyl tetrahydro phthalic anhydride (MeTHPA) and
Step 2) obtained surface grafting has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3Modified powder, stirs equal with glass bar
It is even, then using rotation-revolution mixer, 13min is first rotated under 700r/min rotating speed, then under 1200r/min rotating speed
8min is rotated, mixed liquor is obtained.Mixed liquor is subjected to ultrasonic disperse in 0 DEG C of ice bath, the total time of ultrasonic disperse is
50min, wherein, ultrasonic time 1.5s, ultrasonic gap 1.5s, ultrasonic power is 450W.Accelerator dimethyl is added after ultrasound is complete
Benzylamine (BDMA), first rotates 13min with rotation-revolution mixer under 700r/min rotating speed afterwards, then in 1200r/min
Rotating speed under rotate 8min.Now, nanometer Al2O3Particle is uniformly scatter, and obtains suspension.The surface wherein added connects
Branch has the nanometer Al of silicon oxygen bond, carbon-carbon double bond and amino2O3The quality of modified powder is the 4% of suspension quality, anhydrides solidification
The quality of agent is the 85% of bisphenol A-type glycidyl ether type epoxy resin quality, and the quality of accelerator is bisphenol A-type glycidol
The 1.8% of ether type epoxy resins quality;
4) preparation of epoxy resin composite insulating material
By step 3) obtained suspension is put into vacuum drying chamber, adjusts the temperature to 60 DEG C, pressure be less than 133Pa,
Vacuum outgas 30min.At the same time, to stainless steel metal mould coating release agent, and to coating the stainless of releasing agent at 50 DEG C
Steel metal mould heats 15min, is heated again after coating release agent after taking-up, so repeatedly for three times.Suspension after degassing is poured
Note into the stainless steel mould for having carried out releasing agent processing.Mould is put into vacuum drying chamber again, in 75 DEG C of temperature
And continue vacuum outgas 80min under the pressure less than 133Pa.Finally solidified:First solidify 2.5h at 115 DEG C, then 140
Solidify 13h at DEG C.Cooling, the demoulding, that is, obtain Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulation material after having solidified
Material, specially 4wt%-KH570-PAAM modified Nanos Al2O3/ epoxy resin composite material.
Fig. 1 is Modified by Acrylamide Graft nano aluminium oxide epoxy composite insulating materials made from the embodiment of the present invention 3
SEM sectional drawings, from figure 1 it appears that modified nanometer Al2O3The favorable dispersibility of material in the epoxy, not
Occurs larger agglomeration.The nanometer Al of the present invention2O3Particle after coupling modifier and Modified by Acrylamide Graft,
Being uniformly dispersed in epoxy resin-base, modified Nano Al2O3Particle diameter about 150nm, and be tightly combined with matrix.
The Al for not passing through modifying and decorating is provided in Fig. 2 respectively2O3Particle, KH570 modified Al2O3Particle, KH570
And the common modified Al of acrylamide monomer2O3The Fourier infrared absorption spectrogram of-KH570-PAAM particles.From Fourier
Infared spectrum is visible, the nanometer Al after KH570 is handled2O3Grain is in 1706cm-1There is new absworption peak, correspond to silane
C=O absworption peaks in coupling agent ester group, in 1638cm-1The absworption peak of appearance passes through equivalent to C=C, this explanation silane coupler
Chemistry has been bonded in Al2O3Surface.And Al2O3After being reacted with acrylamide graft, in 1668cm-1There is new characteristic peak, it is right
It should illustrate that acrylamide has been grafted on Al by chemical bond in the characteristic absorption peak of acrylamide amino2O3Surface.
Fig. 3 is that epoxy composite insulating materials punctures Weibull distribution maps.Learnt from figure, epoxy composite insulating materials
Disruptive field intensity be:NC2>NC3>BER>NC1>MC.The present invention by silane coupler and it is acrylic amide modified after nanometer Al2O3
Particle is filled obtained composite insulating material to epoxy resin as filler and shows obvious agreement, from alternating current breakdown
Intensity learns that its breakdown strength can be adjusted by changing filling mixture ratio, as modified nanometer Al2O3Particle is whole
When mass fraction in epoxy composite insulating materials is 3%, its disruptive field intensity reaches maximum, and exchanging degree is with traditional micron
Al2O3/ epoxy resin composite material is compared and improves 26.68%.
Fig. 4 is the thermogravimetric TGA figure curves of epoxy composite insulating materials, and test condition is temperature elevating range in a nitrogen atmosphere
For 50~600 DEG C, heating rate is 10 DEG C/min, it can be seen that with modified Nano Al2O3The addition of particle, epoxy composite is exhausted
The heat endurance of edge material is improved, and it thermally decomposes initial temperature and improved, and the heat when 450 DEG C of materials are decomposed completely
Loss is reduced.And due to temperature when 50~600 DEG C are common device internal power overloads, therefore modified Nano Al2O3Grain
The addition of son improves the heat endurance of epoxy resin to a certain extent, and then can reduce the fault rate of equipment.
Fig. 5 be epoxy composite insulating materials real part of permittivity and frequency between relation, experiment condition be exchange
1VrmsVoltage, a diameter of 30mm of specimen electrode, sample thickness is 0.2mm, and test frequency scope is 0.1Hz~1MHz, experiment temperature
Spend for 25 DEG C.As can be seen that real part of permittivity is constantly reduced with the rise of frequency, Jie of all epoxy composite insulating materials
Electric constant value of real part is all higher than the numerical value of pure epoxy resin.This is due to the modified Nano Al of addition2O3Particle has higher in itself
Dielectric constant.In modified Nano Al2O3Particle is produced with epoxy resin-base causes epoxy composite insulating materials after interfacial effect
Real part of permittivity be improved.
Fig. 6 is relation between the dielectric loss angle tangent value of epoxy composite insulating materials and frequency, it can be seen that NC1 exists
There is a peak during 10Hz, and under the conditions of power frequency 50Hz, NC2 and NC3 loss tangent are less than pure epoxy resin
Loss tangent.HFS (>100Hz) the dielectric loss value of all epoxy composite insulating materials is with pure epoxy resin phase
Than being reduced.