Synthesis of polymers containing pseudohalide groups by cationic polymerization. 17. Oligomerizations of isobutylene with 2-Isothiocyanato-2-phenylpropane/AlEt2Cl/AlEtCl2 or SnCl4 as initiating system. Characterization by means of the off-line combination of GC/MS, SEC, and SFC

Isobutylene (IB) was oligomerized using 2 -isothiocyanato-2-phenylpropane a s initiator in the presence of SnCl4 or a mixture of Lewis acids AIEt(2)Cl/ AlEtCl2. The different oligomers were analyzed by a combination of chromato graphic techniques (supercritical fluid chromatography, size exclusion chro matography, and gas chromatography) and mass spectrometry. The indanic cycl izations occurring after the formation of phi -C+(CH3)(2) and the addition of one IB molecule were limited in the presence of the softest Lewis acid ( SnCl4). Moreover, the combination of SnCl4/dimethyl sulfoxide (DMSO) as an initiating system gave the best results in terms of efficiency of co-initia tion, functionalization (80%), and polydispersity (similar to1.25).