Synthesis and gas permeability of membranes of silyl‐substituted poly( p ‐phenylenevinylene)s

p ‐Bis(bromomethyl)benzene with silyl groups [SiMe 3 ( 2a ), SiEt 3 ( 2b ), SiMe 2 ‐ t ‐Bu ( 2c ), SiMe 2 ‐ n ‐Bu ( 2d ), SiMe 2 ‐ n ‐C 8 H 17 ( 2e ), SiMe 2 ‐ n ‐C 18 H 37 ( 2f )] were polymerized by a modified Gilch route to afford silyl‐substituted poly( p ‐phenylenevinylene)s ( 3a – f ). The polymer containing SiMe 3 groups ( 3a ) was insoluble in any solvents, while the other polymers ( 3b – f ) were soluble in organic solvents. They had relatively high molecular weight over 3.6 × 10 4 , and gave free‐standing membranes by solution casting method. According to thermogravimetric analysis (TGA), the silyl‐substituted poly( p ‐phenylenevinylene)s showed high thermal stability ( T d ≥ 300°C). The oxygen permeability coefficients of membranes of the silyl‐substituted poly( p ‐phenylenevinylene)s ( 3b – f ) were in the range of 3.5–12 barrers, and the poly( p ‐phenylenevinylene)s with long alkyl silyl groups, 3e and 3f , exhibited the highest gas permeability among them. This is the first report on gas permeability of poly( p ‐phenylenevinylene)s. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010