Using a novel microbubble inflation technique developed within our laboratory, we are able to measure the absolute biaxial compliance of polymer films as thin as 13 nm. Experiments performed on both poly(vinyl acetate) (PVAc) and polystyrene (PS) films show that large reductions in the glass transition temperature at the nano-scale are nonuniversal, viz., the PVAc shows no reduction even for the thinnest films while the PS shows a significant reduction at a thickness below approximately 80 nm. More surprisingly, the rubbery plateau region for both materials shows dramatic stiffening (>300 times), perhaps due to surface pinning of the entanglement network. The compliance increases as approximately the square of film thickness.
|Number of pages||3|
|State||Published - Jul 10 2006|
|Event||Society of Plastics Engineers Annual Technical Conference 2006, ANTEC 2006 - Charlotte, NC, United States|
Duration: May 7 2006 → May 11 2006
|Conference||Society of Plastics Engineers Annual Technical Conference 2006, ANTEC 2006|
|Period||05/7/06 → 05/11/06|