The effect of a-substituent on the molecular motion and wetting behavior of poly{2-(perfluorobutyl) ethyl acrylate} [PFA-C-4], poly{2-(perfluorobutyl)ethyl methacrylate} [PFMA-C-4], poly{2-(perfluorobutyl) ethyl alpha-fluoroacrylate} [PFFA-C-4], and poly[2-(perfluorobutypethyl alpha-chloroacrylate} [PFCIA-C-4] films were characterized by dynamic contact angle measurement, lateral force microscopy (LFM), wide angle X-ray diffraction (WAXD), and X-ray photoelectron spectroscopy (XPS). WAXD of oriented PFCIA-C-4 fiber suggested the presence of rod-like chain due to the presence of bulky a-substituent. The glass transition temperature (T-g) of PFFA-C-4 and PFCIA-C4 we(r)e well above the room temperature. The water repellencies of PFFA-C4 and PFC1A-C-4 were as high as that of PFMA-C-4 and their oil repellency of PFFA-C-4 and PFC1A-C-4 was higher than the PFMA-C-4. This result was originated from the low main chain mobility of PFFA-C-4 and PFC1A-C-4 due to the presence of bulky alpha-substituents. The effect of molecular motion on water repellency was clarified by the results of temperature dependence studies of dynamic contact angle, LFM, and surface chemical composition measured by XPS. (C) 2014 Elsevier Ltd. All rights reserved.