Thermal and DMA Characterization of PTFE-PMMA Nanocomposites from Core-Shell Nanoparticles

The thermal and dynamic-mechanical characteristics of three PTFE/PMMA nanoparticle samples are described. The shell forming PMMA, once isolated from the PTFE cores, exhibits a lower thermal stability than the PMMA component in the corresponding nanocomposite under both thermal and oxidative degradation conditions thus indicating a definite, though moderate, thermal reinforcement due to the morphology of the nanocomposites. An increase in the thermal stability under nitrogen atmosphere was observed as the PTFE amount increases. However under air, no difference is observed in the various systems. These observations suggest that only a physical shield can be exerted by the PTFE cores to the PMMA matrix possibly due to a weak interface between PTFE and the PMMA. This hypothesis is also substantiated by the DMA analysis.