Microscopic Structure and Orientation in Solids and Gels of syndiotactic Polystyrene Revealed Using Luminescent Probe Method

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1.Syndiotactic polystyrene (sPS) films including naphthalene (Np) as guest of its nanoporous δ crystalline phase have been prepared and characterized by fluorescence depolarization, X-ray diffraction, and infrared linear dichroism techniques. A nearly perpendicular orientation of the fused rings of Np guest molecules with respect to the chain axis of the δ crystalline structure has been established by an analysis of directions of transition moment vectors of infrared absorption peaks. Moreover, in some sPS films prepared under the aim to orientate the direction of each δ clathrate form crystals in sPS films, the intensities of the polarized fluorescence components of Np were found to change with the angles of the films set against the vibrational direction of polarized light. This method was found to be quite effective to clarify how guest molecules are oriented in films.2.Whether sPS forms gel or not is dependent on solvents. Our fluorescence probe technique clarified that in the case of solvents such as chloroform, benzene, and toluene there are some free volume for them to stay among sPS chains because of the formation of polymer-solvent molecular compounds. Conversely, in the case of solvents such as trans-decalin that are too large to stay among sPS chains, sPS cannot form polymer-solvent molecular compounds and consequently cannot form a perfect gel.3.We found the noble phenomenon that an excitation light beam of a fluorometer can make a sort of hole in gels of sPS. This photo-deformation of the gels has turned out to be related to the formation of a polymer-solvent compound. The vibrational motion of side-chain phenyl groups of sPS excited to the singlet excited state by light is concluded to sweep out solvent molecules having stayed among sPS chains, resulting that the irradiated part changes to a sol form.