Organotin-bridged ionic liquid as a solvent-free, leaching-resistive catalyst for ring opening polymerization of ε-caprolactone

Abstract

A new synthetic route towards a bifunctional ionic liquid-bridged organotrichlorotin derivative has been developed. This newly isolated compound acts as an efficient, solvent-free catalyst in the ROP of ε-caprolactone to provide polymers with controlled molecular weights and narrow dispersity (Đ < 1.2). Owing to its easy removal from the medium, ICP-AES analyses showed a lower level of the residual tin catalyst in the resulting polymer compared to the contamination observed in poly(ε-caprolactone) prepared using a commercial catalyst (3 ppm versus 360 ppm). No toxicity was revealed during antibacterial studies on Staphylococcus epidermidis performed on poly(ε-caprolactone) or on a tin supported catalyst, thereby validating the suitability of this route toward manufacturing biologically-relevant materials.