Synthesis and characterization of perfluoro[1-(2-fluorosulfonyl)ethoxy]ethyl end-capped styrene oligomers

摘要

Styrene oligomers with perfluoro[1-(2-fluorosulfonyl)ethoxy]ethyl end-groups have been synthesized with moderate to high yields (52-97%) via radicaloligomerization by using perfluoro[2-(2-fluorosulfonyl)ethoxyl]propyonyl peroxide (PPP) at various reactant ratios of styrene over PPP (80, 160, 240, 300, 360 and 420) and different temperatures (33,37 and 42 deg C), and characterized by FTIR, ~1H NMR and ~(19)F NMR. The molecular weight of the oligomers measured by gel permeation chromatography (GPC) is dependent on the reactant ratio and reaction temperature. The polydispersity of the oligomers varies from 1.99 to 3.30. The oligomer obtained at the reactant ratio of 300 has the maximum yield (97%) and much broader polydispersity (3.30). The contact angles of water, theta_(H_2O), on the oligomer films are much bigger than that of polystyrene (PS). The glass transition temperatute of the oligomers, T_g, increases with the increase of molecular weight and is lower than that of the parent polymer.