A Redox-Initiated Cascade Approach to Furan-Functionalized Polyisoprene with Time-Dependent Antibacterial Activity

Abstract

A novel furan-functionalized polyisoprene (Furan-PIP) was synthesized via a one-pot, redox-initiated cascade approach using tert-butyl hydroperoxide (TBHP) and tetraethylenepentamine (TEPA) as the initiating system. The polymerization of isoprene proceeded through radical emulsion polymerization, accompanied by in situ epoxidation of the resulting double bonds, followed by ring-opening and furanization reactions. The chemical structure of Furan-PIP was qualitatively characterized by FT-IR and 1H NMR spectroscopy. The appearance of characteristic signals at δ 3.97 and 3.37 ppm (furan ring protons) and δ 8.43 ppm (formyloxy proton) in the 1H NMR spectrum, together with the corresponding FT-IR absorptions at 1725 cm−1 (C=O) and 1015 cm−1 (furan ring), confirmed the successful incorporation of furan and ring-opened moieties. Residual epoxide signals were negligible, indicating near-complete consumption of epoxy groups during the cascade process. Gel permeation chromatography (GPC) revealed a high-molecular-weight polymer (Mn¯ = 45,892 g/mol, PDI = 2.362). The Furan-PIP exhibited a glass transition temperature (Tg) of −49.6 °C and a single-stage thermal degradation at 312 °C. Subsequently, a pre-synthesized antibacterial zinc complex Zn(L-Cl) was physically encapsulated into the Furan-PIP matrix to fabricate a composite material. The composite exhibited time-dependent antibacterial activity against Staphylococcus aureus (S. aureus) over 48 h, leveraging the intrinsic antibacterial property of Zn(L-Cl) previously reported by our group. This work presents a simple and efficient strategy for preparing furan-functionalized elastomers with potential applications in antibacterial materials.