Monday  |  Salon 11  |  04:50 PM–05:10 PM

#15883, Large Deformation Mechanical Response of Hydrogen Bonded Polymer Nanofibers

Incorporation of hydrogen bonds (H-bonds) into polymers has been a successful strategy to simultaneously improve the strength and toughness of polymers. However, despite emerging technological applications at the micron and submicron length scales, existing studies on H-bonded polymers have been limited to the bulk scale. The current study is focused on understanding the mechanical behavior of H-bonded polymers at the submicron length scales. Specifically, individual nanofibers of amorphous poly(vinylpyrrolidone), PVP, H-bonded through a small dopant molecule, tannic acid (TA), of varying diameters (100-1000 nm) and varying H-bond density (i.e., TA concentration) are studied for their elasto-plastic deformation response, using a unique microelectromechanical system (MEMS) based submicron scale tensile test platform. These experiments indicate that nanofibers of smaller diameters are more immune to the detrimental plasticization effects of the small-molecule dopants, while fibers of intermediate diameter range display optimal improvements in elasto-plastic properties due to the addition of TA. This presentation will discuss the complex interdependence of different elasto-plastic responses of PVP-TA nanofibers on fiber diameter and TA composition, and the insights they provide into the molecular micro mechanisms underlying large deformation response of H-bonded polymers in their glassy state.

Adwait Gaikwad   Texas A&M University
Pavan Kolluru   Texas A&M University