Glass Transition Temperature of High Molecular Weight Polystyrene: Effect of Particle Size, Bulk to Micron to Nano
نویسندگان
چکیده
High molecular weight nano/micron sized polystyrene (Mv=1X10) was prepared from styrene and hydrogen peroxide over a range of temperature, shear rate and concentration of catalysts. Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements indicated that the size of particles matched with that of the single polymer chain. The same chemical structure of both nano/micron and bulk polystyrene was confirmed by means of FTIR spectroscopy studies. Thermal analysis indicated that nano/micron sized particles exhibited a significantly higher glass transition temperature (~106C) than micron size particle (~102C) and bulk (Tg = 89C) polystyrene. The effect of particle size on Tg is explained by the existing models of Keddie et al [1], Forrest et al. [2] and Youngli et al. [3]
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