Viscoelastic and flexural properties of epoxy/alumina polymer nanocomposites

Effect of Free Surface Layer and Interfacial Zone on Glass-Transition Behavior of PMMA/CNT Nanocomposite

“…Many models and theories were reported to predict and explain the glass transition. − The glass-transition behaviors of polymers in nanocomposites have received intensive attention because the T g is a crucial factor determining the mechanical and thermal properties of polymer nanocomposites. The glass transition of polymer nanocomposites has been studied both experimentally − and theoretically. , Various materials have been considered for fillers of polymer nanocomposites, including alumina, , silica, clay, graphene, and CNTs. − Many investigations on the glass-transition behaviors of polymer nanocomposites have shown the deviation of glass-transition temperatures from bulk polymers. − The T g s obtained from different research groups also show significant variations. , Ash et al found that the T g of the alumina/PMMA nanocomposite was 25 °C lower than that of the bulk PMMA sample . The alumina nanoparticles in PMMA matrix served as the template of a porous system, where the internal interfaces broke up the percolating structure of spatially heterogeneous dynamic domains and led to a T g reduction. , In a graphene/PMMA composite, the relatively strong interfacial interactions between functionalized graphene sheets and PMMA chains and the geometric constraint effect induced by the nanoscale surface roughness of graphene sheets led to a T g improvement of 30 °C .…”

“…The glass transition of polymer nanocomposites has been studied both experimentally 4−9 and theoretically. 10,11 Various materials have been considered for fillers of polymer nanocomposites, including alumina, 12,13 silica, 14 clay, 15 graphene, 16 and CNTs. 17−19 Many investigations on the glass-transition behaviors of polymer nanocomposites have shown the deviation of glass-transition temperatures from bulk polymers.…”