Ring‐opening polymerization of caprolactone using novel polyaniline salt catalyst

Hybrid composite of polyaniline metal oxide composite, polyaniline‐dodecyl hydrogen sulfate salt with ferric oxide, was prepared for the first time via simple one‐step process of oxidizing aniline with ferric tris(dodecyl sulfate). Ferric tris(dodecyl sulfate) acts as an oxidant, emulsifier, dopant for polyaniline and also source of ferric oxide. Polyaniline salt composites were prepared via aqueous, emulsion, and interfacial polymerization pathways. Polyaniline salt composite was successfully demonstrated as polymer based solid acid catalysts in the ring‐opening polymerization of ε‐caprolactone for the first time. This methodology gave low molecular weight poly(ε‐caprolactone) (MW‐4035) with highly crystalline polymer of flower petals like morphology in 52 wt% yield (with respect to the amount of ε‐caprolactone used). Advantages of this methodology are the use of easily synthesizable, easily handlable, recyclable, cheaper, and eco‐friendly nature of the catalyst. POLYM. ENG. SCI., 55:2245–2249, 2015. © 2015 Society of Plastics Engineers