Transient Interfacial Instability in Bilayer Polymer Films As Observed by Neutron Reflectivity Studies
M Hayashia, TT Hashimoto, M J. Weber, H Grull, A R. Esker, Charles C. Han, Sushil K. Satija
We investigated fundamental processes involved in reactive blending of a system composed of polyamide (PA) and deuterated polysulfone having a reactive end group(R ) (dPSU-R) diluted with a low molecular mass polysulfone (low-PSU) by neutron reflectivity (NR). For this purpose we prepared bilayer films composed of a film of a uniform mixture of dPSU-R/low-PSU and a film of PA. We found an intriguing phenomenon associated with the transient instability of interface between the PA layer and the DPSU-R/low-PSU layer during annealing at high temperatures for chemical reaction between dPSU-R end-group and amine end groups of PA. The transient interface instability, as observed by a transient disappearance of the reflectivity fringes followed by a subsequent recovery of the fringes during annealing at the reaction temperatures, was found to be caused by a transient interdiffusion of a small molecular mass fraction of low-PSU into the PA layer and to be coupled with the Kerkendall effect, a shift of the average position of the interface due to the interdiffusion. Thus the special Kerkendall effect observed here was accompanied by the transient interface instability.
, Hashimoto, T.
, Weber, M.
, Grull, H.
, Esker, A.
, Han, C.
and Satija, S.
Transient Interfacial Instability in Bilayer Polymer Films As Observed by Neutron Reflectivity Studies, Macromolecules, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=851723
(Accessed February 22, 2024)