Cationic polymerization of 2-vinylthiophene - the polymer structure formation

Summary

The cationic polymerization of 2-vinylthiophene (VT) has been studied in solution and on the surface of silica particles. For this purpose different cationically active initiators have been used, e.g. SnCl₄, CF₃SO₃H, and CF₃COOH in homogeneous solution as well as (4-CH₃OC₆H₄)₂CH-Cl and (C₆H₅)₃CCl in conjunction with silica nanoparticles in a slurry. For all experiments a high conversion of VT to oligomers with M_n= 1500 −2000 g/mol (M_w/M_n= 1.4) (Tg = 109 °C) and oligoVT/silica hybrid particles, respectively, have been observed. The different head and endgroups have been ascertained by means of MALDI TOF spectroscopy. Different NMR spectra analyses of the oligomers show that both the vinyl double bond and the five position of the thiophene ring are involved in the propagation reaction.