FR2880350A1 - New doping macromonomer agent, for the preparation of conductive polyaniline, useful in e.g. conductive coatings and films and for the manufacture of glues, hairsprays and inks or paints applicable as absorbent of electromagnetic waves - Google Patents

Abstract

Doping macromonomer agent (I), for the preparation of conductive polyaniline (T), is new. Doping macromonomer agent of formula (I), for the preparation of conducting polyaniline (T), is new. R : hydrosoluble flexible and elastic surfactant; and R' : alkane or aromatic ring (both associated with an acid group). Independent claims are also included for: (1) the preparation of (T) comprising reaction of an aniline compound of formula (II) with a dopant (A) in the presence of an oxidizing agent and water to give (T) of formula (III); and (2) polyaniline (T1) obtained by the process having an average dispersion size of =300 nm, solubility in water of 15-20 wt.% and electric conductivity of up to 10 Ohm-1>/cm. [Image] [Image].

Description

R He R- He R '0 0

  PROCESS FOR THE PRODUCTION OF POLYANILINE DOPED HYDROSOLUBLE, POLYANILINE OBTAINED, COMPOSITIONS INCLUDING THE SAME

USES

  The present invention relates to a process for producing water-soluble doped polyaniline.

  The invention also covers dopants for the manufacture of polyaniline, the polyaniline obtained, the compositions including it and their use for the manufacture of conductive materials.

  Conductive polymers are increasingly sought after in industry for their great potential for application in various fields.

  A wide variety of conductive polymer composites with various structures and specific properties have thus emerged in recent years. Of the intrinsic conductive polymers which are of growing interest, polyaniline is particularly known.

  The polyaniline is derived from the polymerization of aniline. It is obtained in a standard conductive form which has poor electrical and mechanical properties preventing its use for the production of conductive materials. The conductive standard form of the polyaniline is therefore generally treated in an alkaline medium to give a non-conductive base form from which a conductive polyaniline with satisfactory electrical properties can then be obtained.

  To be conductive, the non-conductive base form of the polyaniline must undergo a protonation or oxidation step with a doping product. Among the doping agents capable of making the polyaniline conductive, mention may be made of camphor sulphonic acid, dodecylbenzene sulphonic acid, diesters of phosphoric acids, or metal salts such as iron chlorides and aluminum chlorides.

  The polyaniline thus doped has many advantages which make it a polymer of choice for the constitution of conductive composite materials. However, the manufacture of dispersions or solutions based on conductive polyaniline remains difficult to achieve. Indeed, polyaniline is insoluble and infusible in common solvents, which makes it difficult to use in an aqueous medium.

  Various techniques are known which attempt to render the conductive polyaniline soluble, dispersible and stable in water.

  One method consists in using organic acids as dopants during the polymerization of aniline. in this method, water-soluble complexes of aniline are formed by the introduction of water-soluble organic acids. This allows, during the polymerization reaction, to work in a homogeneous aqueous medium. However, in practice, this method provides a dispersion of polyaniline in water whose stability does not exceed 12 hours, there is sedimentation of the polymer.

  Another technique for obtaining water-soluble polyaniline is to sulfonate the polyaniline in its non-conductive base form with fuming sulfuric acid. This path, described by Marc Biarmid et al; J.Am.Chem Soc 1991, 113, 2665 and Epstein et al; A.J.Polymer 1992, 33, 4409, allows to obtain a soluble polyaniline but of low molecular weight, which limits very strongly the electrical and mechanical properties of the material obtained.

  Finally, many publications describe the use of water-soluble polyelectrolytes or neutral polymers to stabilize the doped polyaniline in water. However, in these studies, the doped conductive polymer content does not exceed 30% by weight of the dry extract: the mixture containing the neutral polymers. As regards the solubility in water of the doped polyaniline, it is limited since it precipitates as soon as the level of doped polyaniline present in the mixture exceeds a rate of about 30% by weight. In addition, the thermal stability of the electrical properties at high temperature is limited or even poor and the use of hydrochloric acid as a dopant causes significant corrosive effects for temperatures above 80 C. In fact, at these temperatures, the combined chlorine in the polymer turns into hydrochloric acid.

  From a practical point of view in industrial installations and because of environmental constraints, it is important today to formulate conductive polymers in an aqueous medium.

  The present invention therefore aims to obtain conductive polyaniline that is both soluble, dispersible and stable in water, and which has good electrical and mechanical properties, as well as good thermal stability. For this, the invention provides a process for producing water-soluble doped polyaniline which consists in involving macromonomer dopants of well-defined mass and chemical structure.

  More particularly, the process for producing doped polyaniline according to the present invention involves macromonomer doping agents containing acidic, acidic multiphosphonic or multicarboxylic acid multisulfonic functions separated by a flexible, hydrophilic and adjustable tensor.

  The dopants involved in the manufacture of the polyaniline according to the invention give the polyaniline high water solubility, good thermal stability and good electrical and mechanical properties. It is specified that for the present invention the term "polyaniline" also refers to substituted forms of polyaniline at the aromatic ring or nitrogen atom.

  The conductive polyaniline obtained according to the present invention can be dispersed or solubilized in water for subsequent use as such or in blends with other polymers for the manufacture of electrically conductive materials.

  The present invention thus relates to: dopants for producing conductive polyaniline, a process for producing conductive polyaniline using these dopants, water-soluble conductive doped polyaniline obtained, compositions that may include this polyaniline, and the use of these compositions for the manufacture of conductive or semi-conductive materials of electricity.

  The invention is now described in detail with reference to the examples and the appended figures in which: FIG. 1 represents the electrical conductivity in Ohm-1 / cm of a polyaniline / polyvinyl acetate material as a function of the weight percentage of doped polyaniline; according to the invention contained in the material, and - Figure 2 shows accelerated aging at 210 C in air for one hour of the electrical conductivity of a conductive film of polyaniline obtained according to the present invention.

  1 / MANUFACTURING PROCESS The method for manufacturing doped polyaniline according to the invention consists in polymerizing aniline in the presence of at least one dopant (A) and optionally other additives such as plasticizers, surfactants, binders or still dyes.

  The reaction that occurs is as follows: Aniline Polyaniline NH2 The doped polyaniline obtained is then purified in an alcoholic medium and redissolved in demineralized water.

  The dopants A used for the polyaniline manufacturing process according to the present invention comprise a hydrophilic, flexible, adjustable and surfactant tensor (R).

  These dopants A correspond to the following general formula: embedded image in which: R is a water-soluble radical, with a surfactant character, and which represents either: a primary or secondary diamine of formula NH C CH 2 , x NH nx and n being integers, x varying between 1 and 5 and n varying between 1 and 20 É a polyethylene glycol of formula O [CH 2 CH 2 O) n n being an integer between 1 and 20, and preferably between 1 and 20; 14.

  A polyethylene oxide of formula O [CH 2 O) n n being an integer between 1 and 20, and preferably between 1 and 14.

  A glycerol of formula CH 2 O O CH 2 CH

N O

  R 'represents either: an alkane, associated with an acidic group, of formula CH2 RO in which R0 represents 503H, P03H2 or COOH, E at least one aromatic ring, containing a plurality of acidic groups, of formula R2 R3 R1 25 R4 R5 wherein: - R1 represents 503H, P03H2 or COOH, - R2 represents H, OH, CH3 (CH2) x (x = 0,1,2,3 ...), NO2, 503H, Cl or Br, - R3 represents H, OH, 503H, Cl or Br, - R4 is H, OH, 50H, Cl or Br, and - R5 is H, OH or 503H.

  The yield of the polymerization reaction of the polyaniline according to the manufacturing method according to the invention is greater than 80%.

  2 / CHARACTERIZATION OF THE DOPED POLYANILINE OBTAINED ACCORDING TO THE PRESENT INVENTION The doped polyaniline obtained according to the invention has: a solubility in water of 15 to 20% by weight, and this, even when the content of polyaniline doped in a mixture with water-soluble polymers is greater than 60% by weight, - stability in water for more than one year under ambient storage conditions, - electrical properties up to 10 Ohm-1 / cm as the shows Figure 1; FIG. 2 also shows that the thermal stability of these electrical properties are good, interesting mechanical properties which result in a great flexibility and great flexibility of the conducting films which contain it, and a mean size in dispersion less than or equal to at 300nm. 3 / USES OF THE POLYANILINE OBTAINED ACCORDING TO THE PRESENT INVENTION The polyaniline obtained according to the invention may be reformulated by adding other additives, such as plasticizers, surfactants, binders or dyes, in order to produce conductive materials. or semiconductors.

  In particular, the polyaniline obtained according to the invention can be used for the production of polyaniline conductive coatings or films such as glues, lacquers, inks or else applicable paints such as: - electromagnetic wave absorbers, 2880350 8 - shielding against electromagnetic waves, - dissipation of electrostatic charges, - corrosion protection, - transparent electrodes or thin layers in optoelectronic components, in particular due to the small particle size, - physicochemical sensors, - Joule or microwave heating, - Electrochromic materials, - Absorbents of ultraviolet and infrared waves, or antistatic materials, for example flow-through, or applicable to the automotive industry to facilitate the application of paint electrostatically.

4 / EXAMPLE

  4-1 / Synthesis of poly (ethylene glycol) di [(5-sulfosalicylate) ester dopant] Polyethylene glycol [di (5-sulfosalicylate) ester] is an example of a macromonomer dopant useful for the manufacture of polyaniline according to US Pat. 'invention.

  The polyethylene glycol α-di (5-sulfosalicylate) ester has the following formula:

OH

O S O

CH2CH2O

OH O

  Synthesis of the polyethylene glycol α-di (5-sulfosalicylate) ester involves an acid, 5-sulfo-salicylic acid, and a dihydric alcohol, polyethylene glycol (PEG). It consists of the succession of the following steps: 708 g of PEG with a mass of 300 g / mole and 1200 g of 5-sulpho-salicylic acid are mixed under a stream of nitrogen, the mixture is stirred at 120 ° C. for 6 hours, and the doping product obtained is recovered with a yield of 100%. 4-2 / 5 Synthesis of water-soluble doped polyaniline in the presence of dopant aw diF (5-sulfosalicylate) ester of polyethylene glycol The synthesis of polyaniline consists of the following sequence of steps: - an aqueous solution containing 1300 g of aw di [( 5-sulfosalicylate) ester of polyethylene glycol with 1700 g of demineralised water and 250 g of aniline, 2100 g of a 4.7% by weight aqueous solution of polyvinyl alcohol (PVA) are added to this mixture, an oxidizing solution of ammonium persulphate (770 g of ammonium persulfate oxide per 1200 g of demineralized water) is prepared; the ammonium persulfate oxidizing solution is introduced into the mixture at a rate of 200 m.sup.2; 10 minutes, the reaction is allowed to continue for two hours to obtain a stable conductive solution, the solution is precipitated in an alcoholic medium to remove the impurities, and the precipitate obtained is dispersed in demineralized water at 2600 rpm. m inute for 10 minutes.

  18% by weight of dry extract is obtained from a homogeneous and stable solution of doped polyaniline whose electrical conductivity at room temperature is of the order of 10 Ohm-1 / cm.

  4-3 Preparation of polyaniline melts doped with poly (2-sulphosalicylate) esters of polyethylene glycol with a vinyl resin A vinyl resin is mixed with polyaniline doped with a di [(5-sulfosalicylate) ester] of polyethylene glycol, according to increasing charge rates.

  The evolution of the electrical conductivity in Ohm-1 / cm of the mixture as a function of the weight percentage of doped polyaniline present in the mixture is presented in the following table Polyaniline in the mixture (% by weight) Conductivity (Ohm-1 / cm) 0 4.10-n 8.10-5 7.10-3 4.7. These results show that the doped polyvinyl resin / polyaniline mixture becomes conductive with less than 5% of polyaniline obtained according to the present invention.

Claims (9)

  1. Macromonomer doping agent for the manufacture of conductive polyaniline, corresponding to the formula: R II R-II R ' O O   in which - R is a water-soluble, flexible, adjustable and surfactant-type radical, and - R 'represents an alkane associated with an acidic group, or at least one aromatic ring containing at least one acidic group.   2. Macromonomer doping agent for the production of conductive polyaniline according to claim 1, characterized in that R represents: a primary or secondary diamine of formula: NH cl-12 NH xnx and n being integers, x varying between 1 and And n ranging from 1 to 20, or - a polyethylene glycol of formula: ## STR2 ## where nn is an integer between 1 and 20, and preferably between 1 and 14, or a polyethylene oxide of formula: ## STR2 ## being an integer between 1 and 20, and preferably between 1 and 14, or a glycerol of formula: ## STR1 ## 3. Macromonomer doping agent for the manufacture of conductive polyaniline according to claim 1 or 2, characterized in that R ' is an alkane, associated with an acidic group, of the formula: wherein RO is 503H, P03H2 or COOH.   4. Macromonomer doping agent for the manufacture of conductive polyaniline according to claim 1 or 2, characterized in that R 'represents at least one aromatic ring, containing at least one acid function, of formula: R 4 R 5 in which: R 1 represents 503H , P03H2 or COOH, R2 is H, OH, CH3 (CH2) x (x: 0,1,2,3 ...), NO2, 503H, Cl or Br, - R3 is H, OH, 503H, CI or Br, - R4 is H, OH, 503H, Cl or Br, and - R5 is H, OH or 503H.   5. Process for obtaining conductive polyaniline involving the dopant according to one of claims 1 to 4, characterized in that it consists in polymerizing aniline in the presence of said dopant.   6. Process for obtaining conductive polyaniline according to claim 5, characterized in that the following reaction is carried out: NH 2 + A n in which A is the dopant.   7. Process for obtaining conductive polyaniline according to one of claims 5 or 6, characterized in that the yield of the polymerization reaction of the polyaniline is greater than 80%.   8. Polyaniline obtained by carrying out the method according to one of claims 5 to 7, characterized by the following parameters: - an average dispersion size of less than or equal to 300 nm, - a solubility in water of 15 to 20 % by weight, and - electrical conductivity of up to 10 Ohm-1 / cm.   12. Composition comprising polyaniline according to claim 8 characterized in that it contains plasticizers, surfactants, binders or dyes.   13. Use of the composition according to claim 9 for the manufacture of coatings or conductive films of polyaniline 14. Use of the composition according to claim 9 for the manufacture of glues, lacquers, inks or paints applicable as absorbents of electromagnetic waves, shielding against electromagnetic waves, dissipation of electrostatic charges, corrosion protection, transparent electrodes or thin layers in optoelectronic components, physicochemical sensors, Joule or microwave heating, electrochromic materials, ultraviolet absorbers and infrared, or antistatic materials.