Direct functionalization of polyisobutylene by living initiation with α‐methylstyrene epoxide

This article describes the synthesis and characterization of polyisobutylene (PIB) carrying one primary hydroxyl head group and a tertiary chloride end group, [PhC(CH 3 )(CH 2 OH)–PIB–CH 2 C(CH 3 ) 2 Cl] prepared with direct functionalization via initiation. The polymerization of isobutylene was initiated with the α‐methylstyrene epoxide/titanium tetrachloride system. Living conditions were obtained from −75 to −50 °C (198–223 K). Low molecular weight samples (number‐average molecular weight ∼ 4000 g/mol) were prepared under suitable conditions and characterized by Fourier transform infrared and 1 H NMR spectroscopy. The presence of primary hydroxyl head groups in PIB was verified by both methods. Quantitative Fourier transform infrared with 2‐phenyl‐1‐propanol calibration and 1 H NMR performed on both the hydroxyl‐functionalized PIB and its reaction product with trimethylchlorosilane showed that each polymer chain carried one primary hydroxyl head group. The synthetic methodology presented here is an effective and simple route for the direct functionalization of PIB.