| 초록 |
The glass transition temperature (Tg) and conversion(α) were measured for an epoxy/aromatic amine system incorporated with POSS. Samples isothermally cured at varying cure temperatures and times were analyzed by DSC. Tg vs. ln(time) data at an arbitrary reference were superposed by time-temperature shifts to form a master curve for the kinetically controlled reaction, and the shifts factors were used to calculate an Arrhenius activation energy. Influence of POSS was investigated from Tg vs. α data, which in turn were fitted with two models; DiBenedetto and Venditti/Gillham equation. It was found that POSS molecules affects differently in the whole conversion range. For lower conversions, the inorganic cage of the incorporated POSS up to 20 wt% may reduce segmental mobility, giving rise to an increase in Tg, However, above the 20 wt% POSS, there was a depression of Tg which may be associated with a plasticizing effect of organic substituent of the POSS molecules. |
