Vinyl aniline modified cyclohexanone formaldehyde resins

Abstract

PurposeThe purpose of this paper is to investigate in situ modification of cyclohexanone‐formaldehyde resins (CFR) by 4‐vinyl aniline (Van). The roles of the reaction temperature, the conductivity, thermal properties, and molecular weight of the product were investigated. CFR was in situ modified with VAn in the presence of sodium hydroxide. Ketonic resin‐bound 4‐vinyl aniline was synthesised with a one‐step method of in situ modification of ketonic resin. The roles of the reaction temperature and the conductivity of the product were investigated.Design/methodology/approachKetone, formalin (37% aqueous solution), vinyl aniline were mixed and then 20% aqueous NaOH solution was added to produce the resin. The solubility, molecular weight and thermal properties of the products were investigated.FindingsThe 4‐vinyl aniline modified cyclohexanone‐formaldehyde resins were found to have conductivity values of 10−4 and 10−2 S/cm and may be considered as conductive ketonic resin. Soluble and processable conductive ketonic resins were developed.Research limitations/implicationsThe reaction mixture of CFR must be stirred continuously at low temperature. Subsequently, 37% formalin was added dropwise in equal portions while refluxing. Temperature should be controlled to prevent the thermal polymerisation of vinyl group and higher branching of amino groups. The amount of vinyl aniline used in reaction mixture is limited since the formed resin may become insoluble in common organic solvents.Practical implicationsThis study provides technical information for the synthesis of conducting resins. The modified resins contain vinyl groups. The chemical redox or radical system can be used to polymerise these vinyl groups and resins with much higher molecular weight may be produced. The resins may also promote the adhesive strength of a coating and corrosion inhibition to metal surfaces of a coating.Originality/valueVinyl aniline modified cyclohexanone formaldehyde resins have been synthesised in the presence of a basice catalyst. These soluble and conductive resins may overcome difficulties in the applications of conducting polymers and open new application areas. Therefore, the vinyl aniline modified resin may find a number of new application areas, as well as existing conducting resin and polymer applications.

In situ modification of cyclohexanone formaldehyde resin with boric acid for high‐performance applications

“…The formation of BCFR starts with an aldollike reaction after a base‐catalyzed elimination reaction of water from hydroxymethyl derivatives of cyclohexanone 13–21. The reaction of boric acid with hydroxymethyl groups precedes that of boric acid with the hydroxy methyl of cyclohexanone 7.…”

“…Because of its good compatibility, it is usually used as a coating additive. Common in situ modified CFRs have been formed from cyclohexanone, formaldehyde, and modifier compounds in the presence of sodium hydroxide 13–21. The effects of the type of modifier compound and concentration, solubility, molecular weight, and thermal properties of modified CFRs have been investigated.…”

“…The effects of the type of modifier compound and concentration, solubility, molecular weight, and thermal properties of modified CFRs have been investigated. The modifier compounds included phenols, bisphenols, melamine, p ‐toluenesulfonamide,13, 14 salicylic acid, o ‐cresol, p ‐cresol, citric acid,15 polydimethylsiloxane,16 aniline, 4‐aminodiphenylamine and N,N ′‐diphenyl‐1,4‐phenylenediamine,17 carbazole‐9‐carbonyl chloride,18 carbazole,19 lignosulfonate,20 and 4‐vinyl aniline 21. Ketonic resin has a methylene group and hydroxymethyl groups, so it has a relatively higher free rotation and mobility.…”

Polypyrrole–vinyl aniline modified cyclohexanone formaldehyde resin copolymers: a comparative study of the resin preparation

“…All of the chemicals were used without further purification. CFVAnR was prepared according to procedures described elsewhere …”

UV‐curing behavior of unsaturated cyclohexanone formaldehyde resins with thiols

“…Due to the weak binding energy of sulfur‐hydrogen bonds, mercapto esters such as pentaerythritol tetra(3‐mercaptopropionate) (PETMP) are preferred in UV‐curing . In various modifiers containing CC double bonds, norbornene‐based modifiers have highest activity in curing reaction because of ring strain . So, 5‐norbornene‐2.3‐dicarboxylic anhydride (NA) can be utilized to cap the chain ends of CFR.…”