Synthesis of Poly(vinylacetylene) Block Copolymers by Atom Transfer Radical Polymerization

The first controlled/living radical polymerization (CRP) of vinylacetylene (VATMS) and synthesis of block copolymers containing poly(vinylacetylene) segments through atom transfer radical copolymerization (ATRP) was reported. ATRP of VATMS was carried out using CuBr/4,4'-di(5-nonyl)-2,2'-bipyridine (dNbpy) 29 as the catalyst. A 50% v/v mixture of anisole or acetone was used as a solvent for polymerization of VATMS in order to dissolve the catalyst and polymer. H NMR spectroscopy was used to follow monomer and solvent, while the molecular weight and the molecular weight distribution were estimated by gel permeation chromatography (GPC) with tetrahydrofuran. the polymerization was less controlled when the reaction was carried out at 90°C, showing a low-molecular-weight shoulder in GPC traces with increasing polydispersity. The FTIR spectrum of the desilylated block copolymer showed the presence of an acetylene C-H stretching vibration peak at 3300 cm -1.