Aniline and oligoaniline modified cyclohexanone‐formaldehyde resins

Purpose Cyclohexanone‐formaldehyde resins (CF‐Rs) were in situ modified with aniline, 4‐aminodiphenylamine, and N‐N′‐diphenyl‐1,4‐phenylene diamine in presence of sodium hydroxide. The purpose of this paper is to report the synthesis of conducting resins with aniline, dimer and trimer aniline, with a one‐step method of in situ modification of ketonic resin. The roles of ketone, aniline concentration, the conductivity of the product are investigated. Design/methodology/approach Ketone, formalin (37 per cent aqueous solution), aniline or oligoaniline were mixed and 20 per cent aqueous NaOH solution was added to produce the resin. Findings The aniline‐modified (CF‐Rs) were found to have conductivity values of 10−3‐10−5 S/cm and may be considered as conductive ketonic resin. Research limitations/implications The reaction mixture must be stirred continuously. Amount of aniline and oligoaniline is limited. Subsequently, 37 per cent formalin was added dropwise in total while refluxing. The amount of aniline is limited since the formed resin may become insoluble in common organic solvents. Practical implications This work provides the application of conducting resins. The modified resins containing aniline groups may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces. Originality/value Aniline formaldehyde, N‐N′‐diphenyl‐1,4‐phenylenediamine‐formaldehyde, aniline‐ and oligoaniline‐modified (CF‐Rs) have been synthesised in the presence of a base catalyst. These resins are conductive resins and the ketonic resins formed have physical properties of both aniline‐formaldehyde resins such as conductivity.