Synthesis of well‐defined chain‐end‐functionalized polystyrenes with four, eight, and sixteen perfluorooctyl groups and their surface characterization

Abstract

AbstractWe have successfully synthesized a series of novel well‐defined chain‐end‐functionalized polystyrenes with a definite number of four, eight, and sixteen perfluorooctyl (C8F17) groups, via living anionic polymerization, by the coupling reaction of chain‐end‐functionalized polystyrenes with dendritic benzyl bromide moieties with the functionalized 1,1‐diphenylalkylanion prepared from sec‐BuLi and 1,1‐bis(4‐tert‐butyldimethylsilyloxyphenyl)ethylene, deprotection, and a Williamson reaction with C8F17(CH2)3Br. The resulting polymers were precisely controlled in molecular weight and molecular weight distribution as well as well‐defined in chain‐end‐functionality. Surface structures of the annealed films cast from such chain‐end‐functionalized polystyrenes with C8F17 groups have been characterized by contact angle and angle‐dependent X‐ray photoelectron spectroscopy (XPS) measurements. It has been clearly observed by both measurements that the C8F17 groups are preferentially segregated from their polystyrene main chains and significantly enriched at the surfaces. However, the degree of enrichment of C8F17 group increased only to a small extent by increasing the C8F17 group from four, eight, and even sixteen in number. We have compared the present results with the previous ones obtained by using chain‐end‐functionalized polystyrenes with one, two, three, and four C8F17 groups and the structurally analogous block copolymers and discussed in more detail in terms of the dependence of enrichment degree on number of C8F17 group. Copyright © 2004 John Wiley & Sons, Ltd.