Synthesis of carboxy‐terminated telechelic oligostyrenes by Dead End Polymerization

Styrene was polymerized with 4,4′‐azobiscyanovaleric acid (ACVA) in order to obtain carboxy‐telechelic polystyrene (CTPS) using the Dead‐End Polymerization (DEP) conditions. First, we focused on experimental conditions leading to oligomers with molecular weights about 2000 g mol−1. Second, we demonstrated by‐products of ACVA radicals are also synthesized in the DEP conditions by combination or by disproportionation. The purification of CTPS was investigated in order to extract the by‐products of ACVA. An extraction of these by‐products in H2O pH 7 is suggested. Finally, the acid functionality of oligostyrene is evaluated by 1H NMR and conductimetric titrations. A functionality about 2 is obtained that confirmed the synthesis of CTPS.