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Ring-opening polymerization of 1,3-dehydroadamantanes (DHAs) such as 1,3-dehydroadamantane (1), 5-butyl-1,3-dehydroadamantane (2), and 5,7-dibutyl-1,3-dehydroadamantane (3) was carried out under various conditions. Poly­(1,3-adamantane)­s were quantitatively obtained by thermal polymerization of DHAs in bulk. Radical polymerization of DHAs with α,α′-azobis­(isobutyronitrile) (AIBN) proceeded in bulk at 80 °C. By contrast, virtually no reactions of DHAs occurred with n-BuLi in n-heptane and phenylmagnesium chloride in tetrahydrofuran (THF), indicating their negative anionic polymerizability. On the other hand, cationic ring-opening polymerization of DHAs smoothly proceeded with super Brønsted acids such as trifluoromethanesulfonic acid (TfOH) or trifluoromethanesulfonimide (Tf2NH) to afford corresponding polymers in good to quantitative yield. Although Tf2NH induced rapid polymerization of DHAs even at −78 °C, higher temperatures such as 0 or 30 °C were necessary to initiate polymerization with TfOH. In the presence of Lewis bases such as ethyl acetate, diethyl ether, or THF, retardation of cationic polymerization was apparently observed, indicating nucleophilic interaction of added bases toward a propagating 1-adamantyl cation derived from DHAs. The resulting poly­(2) bearing a flexible n-butyl group was soluble in various solvents, while highly symmetrical poly­(1) and poly­(3) showed very poor solubility. The M n value of the cationically obtained poly­(2) reached 6900, and the degree of polymerization was estimated to be greater than 30. The resulting poly­(1,3-adamantane)­s showed high thermal stability in thermogravimetric analysis (TGA), and the 10% weight loss temperatures of poly­(1), poly­(2), and poly­(3) were respectively 480, 488, and 477 °C. Poly­(2) and poly­(3) exhibited a glass transition temperature (T g) at 205 and 139 °C, respectively, in differential scanning calorimetry (DSC) measurements.

We 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.

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A series of well‐defined chain‐end‐functionalized polystyrenes with a definite number of two, four, eight, sixteen, and thirty‐two C8F17 groups have been successfully synthesized by applying the recently developed methodology based on an iterative divergent approach. These polymers were precisely controlled in chain length and degree of end‐functionalization. The surface structures of films cast from these polymers have been characterized by XPS and contact angle measurements. Significant segregation and preferential enrichment of C8F17 group at the surfaces were observed in all films. The surface enrichment estimated from F atomic % measured by XPS increased markedly with increasing the number of C8F17 group from two to four, but almost saturated at the number of four where the F atomic % from top surface to 20 Å depths was 44.2 %. The surface enrichment was enhanced only a small extent by further increasing the number of C8F17 group, although the maximum values (49.8 %) were obtained with chain‐end‐functionalized polystyrenes with sixteen and thirty‐two C8F17 groups.