Polycaprolactone degradation under the action of iodine vapor

Upon the solid-state degradation of poly(ε-caprolactone) under the action of iodine vapor, the number-average molecular weight of the polymer decreased by almost an order of magnitude 48 h after the incorporation of iodine (~6 wt%) from a gaseous phase. A polymer degradation mechanism through the cleavage of C–O bonds in the polymer backbones with the formation of a charge-transfer complex and the participation of water or polyiodide ions was proposed.