화학공학소재연구정보센터
Polymer, Vol.42, No.21, 8959-8964, 2001
Surface relaxation behavior of proton- and perfluoroalkyl-terminated poly(2-vinylpyridine) films
Proton- and perfluoroalkyl-terminated poly(2-vinylpyridine) (P2VP-H and P2VP-C2C8F) were anionically synthesized. Surface molecular motions of P2VP-H and P2VP-C2C8F films prepared on hydrophilic silicon wafers were examined by lateral force microscopy (LFM). Surface glass transition temperature, T-g(s), of P2VP-C2C8F was lower than that of P2VP-H probably due to the difference of the surface concentration of chain ends. Also, both T-g(s) values were lower than each corresponding bulk glass transition temperature, T-g(s). Surface molecular motion in an ultrathin film was less activated than that of the thick film, although Tin the ultrathin film remained lower than T-g(b). In the case of ultrathin films, the surface/interface area to volume ratio becomes larger, and thus the thermal molecular motion at the surface is affected by that at the polymer/substrate interface. Since molecular mobility on the substrate might be restricted owing to the polar attractive interaction between polymer segments and the hydrophilic substrate, the activation of surface molecular motion apparently turns weak for such an ultrathin film.