Free Volumes in Polymer Nanocomposites
Glass transition temperatures of polystyrene and inorganic nanocomposites were reported to vary with the content and the binding strength between the polymers and the nano particles by the DSC method 1. We have employed positron annihilation spectroscopy to measure the free volumes of polystyrene and modified functional groups with addition of silicone oxide, clay, carbon nanofiber nano particles and carbon dioxide 2 as a function of composition and of temperature. We found that the glass transition temperatures (Tg) significantly decrease as a function of nano particle compositions and the extent of Tg variation depends on the interfacial binding strengths between the nano particles and the polymer matrices. The positron results are compared with the DSC data in the same systems. Free volumes properties such as size distribution, thermal expansion coefficients, and the depth profiles of polymer composites and functional modifications and polymers on different substrates will be also reported.
H.M.Chen L.James Lee Jintao Yang Xiaohong Gu Y.C.Jean
Department of Chemistry,University of Missouri-Kansas City,Kansas City,Missouri,64110,USA Department of Chemical and Biomolecular Engineering,The Ohio State University,Columbus,Ohio 43210,US Department of Chemistry,University of Missouri-Kansas City,Kansas City,Missouri,64110,USA;Materials
国际会议
第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)
武汉
英文
36
2008-05-11（万方平台首次上网日期，不代表论文的发表时间）