Studies on the Thermal Stability and Degradation Kinetics of Pd/PC Nanocomposites

Abstract

Effect of heating rate, Pd content, and synthesis method on the thermal stability of the ex situ and in situ Palladium/polycarbonate (Pd/PC) nanocomposites was investigated. TEM images revealed discrete Pd nanoclusters of about 5 and 15 rim sizes for 1 and 2 vol % ex situ nanocomposites, respectively. However, agglomerated Pd nanoclusters were noticed in the in situ samples, irrespective of the Pd content. The ex situ Pd/PC nanocomposites showed high onset temperature (Ti) for thermal degradation of PC than the in situ and pure PC samples. Pd content and heating rates were found to have a positive influence on the Ti and Tin (temperature at the maximum degradation rate occurs) of the Pd/PC nanocomposites. Thermal degradation of the PC was found to follow the first-order kinetics in the Pd/PC nanocomposites. The activation energies associated with the degradation were determined by using the Kissinger method. These activation energies are used to construct the Master decomposition curve (MDC) and weight-time-temperature (alpha-t-T) plots that describe the time-temperature dependence of the PC pyrolysis in the Pd/PC nanocomposites. These constructed alpha-t-T plots were validated with the data from isothermal measurements. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 3602-3611,2010