Polymer-based carbon conductivity macromolecule composite material
One, technical field
The present invention relates to the conducing composite material technical field, more particularly, relate to a kind of by polymeric matrix be scattered in the conductive polymer composite that the conductive filler in the polymer is combined into.
Two, background technology
Conductive polymeric composite is meant the heterogeneous composite material with conducting function that is made of by different combination process polymer and various conductive fillers, and it had both had conducting function, simultaneously again with the superiority of macromolecular material.Compare with the structural conductive macromolecular material, it is stable lasting to have electric conductivity, the raw material source is sufficient, the technology controllable degree is better, being easy to industrialization produces continuously, characteristics such as nontoxic nothing is corroded, and manufacturing cost is lower have purposes widely in fields such as antistatic, microwave absorbing, electromagnetic shielding and electrochemistry.Along with the modernization of science and technology and developing rapidly of electronics industry, the demand of this new material is increasing.Therefore, since the eighties, research and develop the activity of high performance conductive polymeric composite and just leap very much.
Traditional conducing composite material is to adopt the preparation of conductive filler lamination composite algorithm, carbon fiber felt, and conductive layer such as woven wire and high molecule plastic base layer overlapping layers force together, thereby obtain conductive plastics.As the packing layer of electric conductor, except carbon fiber felt, woven wire, the fabric of plating, metallized plastic film etc. also can be used as intermediate conductive layer, form sandwich structure with plastic basis material.Owing to adopt the conducing composite material of conductive filler lamination composite algorithm preparation, have conduction material and be evenly distributed, conduct electricity that mechanical strength that dosing of layered material can not make goods descends and conductive filler can not expose advantages such as product surface, therefore quite be subjected to the favor of many conducting polymer composites manufacturer.It is that plastic layer, the upper strata of adding aluminium foil is the conductive plastic object that does not add the plastic layer of aluminium foil that Aron Kasei corporate system has been produced bottom.The Dow Chemical Co. (US) 2030 Dow Center, Abbott Road, Midland, Michigan 48640, has developed the lamination composite plastic of metallized PC film and the formation of ABS film resin, and its effectiveness is 35-40dB.Cabot Belgium company has developed by low-cost conducting polyaniline ethene sandwich layer and the lamination compound conductive plastic made of the PPO surface layer of filled conductive filler not, is used for a kind of case of computer.But the place of adopting conductive filler lamination composite algorithm to prepare the conducing composite material deficiency is that the composite conducting material processing and preparing is difficulty relatively, the difficult adjustment of the electric conductivity of conducing composite material.
Surface conductance film forming method is to grow up on the basis of conductive filler lamination composite algorithm, adopt methods such as plating, vacuum evaporation, ion plating, sputter, spraying or surface-coated to form layer of metal film or other conducting film, make it to have conduction, electromagnetic wave shielding, function such as antistatic on the high molecular polymer surface.The surface conductance polymer composite of Xing Chenging according to the method, conducing composite material with the preparation of conductive filler lamination composite algorithm is essentially identical on performance in essence, all belong to the structural conductive macromolecular composite material, therefore have and the essentially identical pluses and minuses of conducing composite material that prepare according to conductive filler lamination composite algorithm.
In order to overcome the deficiency that conductive filler lamination composite algorithm and surface conductance film forming method exist, people have researched and developed out conductive filler again and have disperseed composite algorithm.The basic process that adopts conductive filler to disperse composite algorithm to prepare conductive polymer composite is, conductive filler is mixed with polymeric matrix material, conductive filler is dispersed in the polymeric matrix material, the formation composite conducting material.Adopt conductive filler to disperse composite algorithm to prepare conductive polymer composite, because the electric conductivity of composite material is easy to adjust, processing and preparing technology is simple, so this method is to prepare the most frequently used method of conducing composite material.Adopt this method to can be used to make conductive rubber, conductive plastics, electrically-conducting paint, conductive adhesive etc.The problem that conductive filler disperses composite algorithm to exist mainly contains: 1. the distribution of conductive filler in goods is often inhomogeneous, thereby makes manufactured goods conductivity everywhere inconsistent.2. the caking property between conductive filler and the matrix resin is generally relatively poor, and especially this situation is particularly evident when conductive filler content is higher.Bonding is bad between conductive filler and the matrix resin, and the mechanical performance of the conducing composite material goods after the moulding is descended greatly.3. the conductive filler of high filler loading capacity, its goods are in use because coming off of conductive filler can cause environmental pollution.Solve the method for conductive filler skewness problem, prior art generally is that conductive filler is evenly distributed in matrix resin, adhesion problem then mainly is by add coupling agent and other processing aid in prescription between solution conductive filler and the matrix resin, simultaneously under the situation that goods electricity and mechanical property do not descend, the consumption that as far as possible reduces conductive filler solves.So, determine suitable prescription, developing novel low sizing content electric conducting material becomes the interior important topic of this research field.
In order to overcome the deficiency that conductive filler is scattered in the conductive polymer composite of single polymer formation, people have developed and have adopted inconsistent two-phase polymer to prepare conductive polymer composite as matrix in recent years, in the hope of reducing the loading of conductive filler in the compound-type conducting polymer effectively, further reduce the resistivity of conductive polymer composite, improve the mechanical performance of conductive polymer composite, or do not reduce the mechanical performance of conductive polymer composite at least.But the conductive polymer composite of preparing as matrix with inconsistent two-phase polymer of prior art, do not realize the intended purposes of its developmental research, the conductive polymer composite of being researched and developed out, the resistivity of material is still than higher, the content of conductive filler is still higher, though the resistivity of material decreases, the mechanical performance of material is reduced too widely.Therefore it is low to research and develop the conductive filler content and the resistivity that make new advances, and the important topic that the composite conductive polymer composite material is still the present technique field is filled in the dispersion of mechanical performance and good processability.
Three, summary of the invention
The objective of the invention is present situation, a kind of new have low conductive filler loading, the polymer-based carbon conductivity macromolecule composite material of high conduction performance are provided at the preparation polymer base conductive composite material.
Conducing composite material with low conductive filler loading and high conduction performance provided by the invention, comprise that mainly as the polymer of matrices of composite material and the charcoal that is scattered in the polymer be conductive filler, described matrix polymer and charcoal be in the conductive filler at least the first form by being no less than two kinds of different materials, be that matrix polymer comprises and is no less than two kinds of different polymeric materials and/or charcoal is that conductive filler comprises that being no less than two kinds of different charcoals is conductive filler, and charcoal is that weight content shared weight range in composite material of electric conducting material is generally 0.1~50%, preferential range of choice is 0.5~30%, and optimum range is 2.0~15%.
In technique scheme, described polymer can be formed by being selected from two-phase polymers different in polypropylene, ethylene-acrylic acid copolymer, nylon, the ethylene-octene copolymer at least, and wherein polar polymer and non-polar polymer at least each one mutually, and charcoal be conductive filler is a kind of single raw material of wood-charcoal material.Preferably by polypropylene, ethylene-acrylic acid copolymer two phase compositions, the ratio of polypropylene and ethylene-acrylic acid copolymer can be 50/50 to 90/10 to polymer, and the preferential ratio of selecting is 60/40 to 80/20.
In technique scheme, described charcoal is that conductive filler can be formed by two kinds that are selected from least in carbon black, graphite, carbon fiber, Single Walled Carbon Nanotube, multi-walled carbon nano-tubes or its compound, and matrix polymer is to can be a single gathering compound.Charcoal is that conductive filler preferably is made up of carbon black and carbon nano-tube, and the ratio of carbon black and carbon nano-tube can be 15: 1-20: 1.The electric conductivity of carbon nano-tube is relatively good, and price is also somewhat expensive, and the ratio of carbon black and carbon nano-tube mainly is to determine according to the consideration of this two aspect.
In technique scheme, be that the raw material of wood-charcoal material of conductive filler can be the raw material of wood-charcoal material of handling through chemical modification as charcoal.Different raw material of wood-charcoal material also can cooperatively interact to use and constitute complex conductive fillers.
In polymer-based carbon conductivity macromolecule composite material, can also contain in the auxiliary agents such as coupling agent, lubricant, antioxidant and inorganic filler one or more.
Polymer-based carbon conductivity macromolecule composite material provided by the invention can adopt the method preparation of polymer is direct and raw material of wood-charcoal material melt blending, this preparation method's technology is simply easy to implement, the even dispersion of raw material of wood-charcoal material can be realized, and the dispersity of raw material of wood-charcoal material in each phase matrix can be controlled.
Of the present invention finishing is based on electrical conduction mechanism profound understanding and the research of inventor to polymer-based carbon conductivity macromolecule composite material.The percolation threshold of polymer is relevant with the heterogeneous distribution of filler in the two-phase polymer matrix.Two kinds of situations are arranged: 1. the filler precedence partition is in a phase wherein, form comparatively uniformly in mutually at this and to distribute, this moment, percolation threshold depended on the concentration of filler in enrichment mutually and the continuity of this phase, when the filler enrichment forms continuous phase mutually, promptly realize dual diafiltration (double percolation), can obtain than the single percolation threshold that the composition polymer/the conductive filler composite material is low; 2. polymeric matrix forms the co-continuous phase, and filler is positioned at the co-continuous phase at the interface, and the percolation threshold of compound system will significantly reduce like this.3. the raw material of wood-charcoal material is different with interaction performance between the different polymer, begins to form the percolation threshold difference of conductive network in polymer, and the consumption of raw material of wood-charcoal material is with different.4. adopt raw material of wood-charcoal material and single polymers blend, its conductivity percolation threshold is generally all higher, and is difficult for processing, because higher raw material of wood-charcoal material content has increased the melt viscosity of blend and can reduce its mechanical property.
Polymer-based carbon conductivity macromolecule composite material provided by the invention, make matrix by adopting two-phase polymer, the consumption that makes conductive filler be heterogeneous distribution in each phase to reduce conductive filler (as carbon black optionally be dispersed in the polarity elastomer mutually in, the polarity elastomer forms the conductive path of contiguous network structure in the middle of another matrix simultaneously), the electric conductivity of raising material.Adopt two kinds of raw material of wood-charcoal material to make conductive filler, particularly adopt carbon black and carbon nano-tube to make conductive filler, because two kinds of raw material of wood-charcoal material have different spatial geometric shapes and different conductive characteristics, (for example having very, the carbon nano-tube of big L/D ratio mainly provides long-range conduction to utilize its mutual overlap joint, carbon black not only provides the short range conduction, but also the overlap joint between the carbon nano-tube is played " bridge joint " effect, when the content of carbon nano-tube in the component is very low, average distance between the nanotube is very big, touch opportunity seldom, basically do not have conductive channel) more perfect and the stable conductive network structure that forms, the single relatively raw material of wood-charcoal material of electric conductivity that obtains material is improving several orders of magnitude under the content equally.The present invention can by changing the consumption of raw material of wood-charcoal material, regulate the room temperature resistivity of composite material according to the requirement of serviceability.
Before the present invention finishes, the conducing composite material technical field generally believes, adopt inconsistent two-phase polymer and make it form the co-continuous phase,, often cause the mechanical property of compound system to reduce greatly to obtain lower percolation threshold and electric conductivity preferably.The invention solves this technical problem.The two-phase polymer combination that the present invention is adopted in conducing composite material is that prior art did not adopt.Have when significantly improving the conductivity of composite material energy and do not damage its mechanical property, and some mechanical property of material also is significantly improved.In addition, the raw material that is adopted is cheap and easy to get, and the process operation condition is simple, and product easily reclaims recirculation.The compound system of two kinds of raw material of wood-charcoal material that adopted among the present invention also be in the past do not adopt, the electric conductivity of its single relatively raw material of wood-charcoal material compound system improves very remarkable.
Polymer-based carbon conductivity macromolecule composite material provided by the invention is compared with the conducing composite material of prior art, and conclusion is got up, and the major advantage that it had is as follows:
(1) adopt two-phase polymer to make matrix, because the heterogeneous distribution of raw material of wood-charcoal material, the less raw material of wood-charcoal material consumption of single polymers matrix adopting just can reach percolation threshold relatively.
(2) adopt polarity elastomer and non-polar polymer blend as matrix, utilize between polarity elastomer and non-polar polymer and the polarity raw material of wood-charcoal material and all have good compatibility, strengthened the bonding interface between conductive filler and the matrix resin, conductive filler distributes more even in matrix resin, and performance is more stable.
(3) adopt the raw material of wood-charcoal material of two kinds of different spaces geometries to make conductive filler, the more perfect more stable conductive network structure of formation has improved the electric conductivity of material.
(4) can be according to the requirement of serviceability, by changing the consumption of raw material of wood-charcoal material, the room temperature resistivity of flexible composite material.
(5), the mechanical property of material and the infringement of processing characteristics are reduced because the addition of raw material of wood-charcoal material is less.
(6) according to instructions for use, select for use different polymeric matrixs to cooperate, can improve the mechanical property and the serviceability of material.
(7) because the addition of raw material of wood-charcoal material is less, can reduce the environmental pollution that the raw material of wood-charcoal material comes off and causes.
(8) equipment involved in the present invention is simple and easy to, and easy to operate, raw material is easy to get, and production cost is low.
The present invention also has some advantages of others.
Four, embodiment
By the following examples the present invention is further described specifically.In following each embodiment, the ratio of each component is mass percent.Be necessary to be pointed out that at this following examples only are used for that the present invention is described further; can not be interpreted as limiting the scope of the invention; this art skilled person makes some nonessential improvement and adjustment according to the invention described above content to the present invention, still belongs to protection scope of the present invention.
The good effect that the present invention produces can describe with embodiment.
Be example with polypropylene and ethylene-acrylic acid copolymer among the embodiment, but polymeric matrix used in the present invention is not limited to polypropylene and ethylene-acrylic acid copolymer, the raw material of wood-charcoal material that is adopted is conductive carbon black and carbon nano-tube, but the conductive filler that the present invention was suitable for is not limited to conductive carbon black and carbon nano-tube.
Embodiment 1
Raw material is COPP (EPS30R), ethylene-acrylic acid copolymer and conductive carbon black, the ratio of polypropylene and ethylene-acrylic acid copolymer is 80/20, conductive carbon black content is 9%, in 150 ℃ of melt blending 10min in two roller mills, mold pressing laggard capable electric performance test in blocks in vulcanizing press.The specific insulation of the composite material that obtains is 10
6Ω cm, hot strength is 20.9MPa, elongation at break is 325.8%.
Comparative Examples 1
Raw material is polypropylene and conductive carbon black, and conductive carbon black content is 9%, and method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
14Ω cm, hot strength is 26.8MPa, elongation at break is 22.1%.
Embodiment 2
Raw material is HOPP (T30S), ethylene-acrylic acid copolymer and conductive carbon black, the ratio of polypropylene and ethylene-acrylic acid copolymer are 80/20, and conductive carbon black content is 4.76%, method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
8Ω cm.
Comparative Examples 2
Raw material is polypropylene and conductive carbon black, and conductive carbon black content is 4.76%, and method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
15Ω cm.
Embodiment 3
Raw material is the polypropylene identical with embodiment 2, ethylene-acrylic acid copolymer and conductive carbon black, the ratio of polypropylene and ethylene-acrylic acid copolymer are 80/20, and conductive carbon black content is 9%, method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
6Ω cm.
Comparative Examples 3
Raw material is polypropylene and conductive carbon black, and conductive carbon black content is 9%, and method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
14Ω cm.
Embodiment 4
Raw material is the polypropylene identical with embodiment 2, ethylene-acrylic acid copolymer and conductive carbon black, the ratio of polypropylene and ethylene-acrylic acid copolymer are 70/30, and conductive carbon black content is 9%, method is identical with embodiment 1, and the specific insulation of the composite material that obtains is 10
5Ω cm.
Embodiment 5
Raw material is a polypropylene, carbon black and carbon nano-tube, raw material of wood-charcoal material total amount is 9% of a polymer, the ratio of carbon black and carbon nano-tube is 19: 1 (promptly wherein carbon black content is 8.55%, and content of carbon nanotubes is 0.45%), adds raw material in the banbury together, the control rotating speed is at 30rpm, in 180 ℃ of melt blending 10min, mold pressing laggard capable electric performance test in blocks in vulcanizing press, the specific insulation of the composite material that obtains is 10
5Ω cm.
Comparative Examples 5-1
Raw material is polypropylene and carbon nano-tube, and the content of carbon nano-tube is 0.5%, and method is identical with embodiment 4, and the specific insulation of the composite material that obtains is 10
14Ω cm.
Comparative Examples 5-2
Raw material is polypropylene and carbon black, and the content of carbon black is 9%, and method is identical with embodiment 4, and the specific insulation of the composite material that obtains is 10
9Ω cm.
Embodiment 6
Raw material is a polypropylene, carbon black and carbon nano-tube, raw material of wood-charcoal material total amount is 13% of a polymer, the ratio of carbon black and carbon nano-tube is that (promptly wherein carbon black content was 12.35% in 19: 1, content of carbon nanotubes is 0.65%), method is identical with embodiment 4, and the specific insulation of the composite material that obtains is 46 Ω cm.
Comparative Examples 6-1
Raw material is polypropylene and carbon nano-tube, and the content of carbon nano-tube is 1%, and method is identical with embodiment 4, and the specific insulation of the composite material that obtains is 10
14Ω cm.
Comparative Examples 6-2
Raw material is polypropylene and carbon black, and the content of carbon black is 13%, and method is identical with embodiment 4, and the specific insulation of the composite material that obtains is 10
5Ω cm.