Enzymatic synthesis of polyaniline

A process for the enzymatic synthesis of electrically conductive polyaniline comprising:

• reacting together one or more aniline monomers selected from the group consisting of substituted and unsubstituted aniline monomers, an oxidizing agent which comprises an enzyme and an electron acceptor, and an effective acidifying agent in an acidic environment having a pH lower than the pKa of said aniline monomers to form an electrically conductive polyaniline having more than 8 monomer units along the backbone of the polymer chain, wherein said acidifying agent has a pKa lower than the pKa of said aniline monomers, said enzyme is a peroxidase, said process is carried out at a temperature of from about 0.degree. C. to about 100.degree. C., said solvent is selected from the group consisting of water, organic solvents or mixtures thereof, and said electrically conductive polyaniline has an electrical conductivity of at least about 10.sup.-6 S/cm as measured by the four-in-line probe technique, wherein the backbone of said electrically conductive polyaniline has the structure:
• ##STR3## wherein m is an integer from 1 to 5 with the proviso that the sum of n and m is equal to 5 and that at least one position on the aniline ring is a moiety which allows oxidative coupling at that position;
• n is an integer from 0 to 4,
• y is an integer equal to or greater than 0;
• x is an integer equal to or greater than about 0, with the proviso that at least x or y is greater than 0 and that when x and y are greater than 0, the ratio of x to y is greater than or equal to 0.5;
• z is an integer selected such that the number of aniline monomer units along the polymer backbone is greater than 8;
• R.sub.1 is a hydrogen;
• R.sub.2 is the same or different at each occurrence and is selected from the group consisting of alkyl, alkenyl, alkoxy, cycloalkyl, cycloakenyl, alkanoyl, alkylthio, aryloxy, alkylthioalkyl, alkylaryl, arylalkyl, amino, alkylamino, dialkylamino, aryl, alkylsulfinyl, aryloxyalkyl, alkylsulfinylalkyl, alkoxyalkyl, alkylsulfonyl, aryl, arylthio, alkylsulfonylalkyl, arylsulfinyl, alkoxycarbonyl, arylsulfonyl, carboxylic acid, hydroxy, halogen, cyano, sulfonic acid, nitro, mercapto, alkylsilane or alkyl substituted with one or more sulfonic acid, carboxylic acid, halo, nitro, mercapto, cyano or epoxy moieties;
• or any two R.sub.2 groups together may form an alkylene or alkenylene chain completing a 3, 4, 5, 6 or 7 membered aromatic or alicyclic ring, which may optionally include one or more divalent nitrogen, sulfur, sulfonyl, ester, carbonyl, sulfonyl, or oxygen atoms;
• or R.sub.2 is an aliphatic moiety having repeat units of the formula:
• --(OCH.sub.2 CH.sub.2).sub.q O--, or --(OCH.sub.2 CH(CH.sub.3)).sub.q O--
• wherein q is a positive whole number.