Dynamic relaxation characteristics of polymer nanocomposites based on poly(ether imide) and poly(methyl methacrylate)

作者：Comer A C; Heilman A L; Kalika D S^*

来源：Polymer, 2010, 51(22): 5245-5254.

DOI：10.1016/j.polymer.2010.08.053

• Glass transition
• Dynamic mechanical analysis
• Dielectric spectroscopy

The dynamic relaxation characteristics of poly(ether imide) and poly(methyl methacrylate) nanocomposites based on native and surface-modified (i.e., hydrophobic) fumed silicas were investigated by dynamic mechanical analysis and dielectric spectroscopy. The nanocomposites displayed a dual glass transition behavior in the dynamic mechanical studies encompassing a bulk polymer glass transition (close to T(g) for the unfilled polymer), and a second, higher-temperature transition reflecting relaxation of polymer chain segments constrained owing to their proximity to the particle surface. The position and intensity of the higher-temperature transition varied with particle loading and surface chemistry, and reflected the relative populations of segments constrained or immobilized at the particle-polymer interface. Dielectric measurements, which were used to probe the time temperature response across the local sub-glass relaxations, indicated no variation in relaxation characteristics with particle loading.

• 出版日期2010-10-15