An efficient and mild route to highly fluorinated polyolefins via copolymerization of ethylene and 5-perfluoroalkylnorbornenes†
Abstract
A series of fluorinated polyolefins have been efficiently synthesized via the copolymerization of ethylene with 5-(perfluoro-n-alkyl)norbornenes by employing a class of [ONS] titanium catalysts, which possess an open coordination space environment and exhibit excellent tolerance towards fluorine atoms and excellent catalytic activity (up to 1.60 × 106 g (mol h atm)−1). Fluorinated polyolefins with high fluorine contents (up to 44.0 wt%) and high molecular weights (3.5–15.9 × 104 g mol−1) could be obtained under mild conditions. DSC analysis indicated that incorporation of the fluorinated comonomers into polyethylene significantly influences the crystallinity of the polymers (Tm), while it has little influence on the polymer stability.