Synthesis of Allyl Telechelic Poly(4-acetoxystyrene) via Living Cationic Polymerization and Electrophilic Substitution of Allyltrimethylsilane

Living cationic polymerization of 4-acetoxystyrene (STO) was conducted in CH 2 Cl 2 at −15 °C using a dicumyl chloride (DCC)/SnCl 4 / n -Bu 4 NBr initiating system. Impurity moisture initiation was inhibited by adding proton trap 2,6-di-tert-butylpyridine (DTBP), and the controlled initiation of DCC was confirmed by 1 H nuclear magnetic resonance ( 1 H-NMR) spectroscopy and matrix-assisted laser desorption ionization time-of-flight mass (MALDI-TOF-MS) spectrometry. The polymerization kinetics were analyzed to for optimizing the polymerization rate. Allyl-telechelic PSTOs (allyl-PSTO-allyl) with molecular weight ( M n ) range of 3540–7800 g/mol and narrow molecular weight dispersity ( M w / M n ) about 1.25 were prepared through nucleophilic substitution with allyltrimethylsilane (ATMS) at approximately 40% monomer conversion. The experimental results indicate that the substitution efficiency of ATMS increased with higher ATMS concentration, temperature, and extended reaction time. Nearly unity ally-functionality for allyl-PSTO-allyl was achieved by adding sufficient SnCl 4 prior to the substitution.