Characterization of Chemical Heterogeneity in Polymer Systems Using Hydrolysis and Tapping Mode Atomic Force Microscopy
D Ragahavan, X. Gu, Tinh Nguyen, Mark R. VanLandingham
Characterization of polymer coatings microstructure is critical to the fundamental understanding of corrosion of coated metals. In this paper an approach for mapping chemical heterogeneity of a polymer system using chemical modification and tapping mode atomic force microscopy (TMAFM). This approach is based on selective hydrolysis of one of the phases in a multi-phase polymer blend system and the ability of TMAFM to provide nanoscale lateral information about the different phases in the polymer system. Films made of 70:30 polyethyl acrylate/polystyrene (PEA/PS) blend were exposed to a hydrolytic acidic environment and analyzed using TMAFM. Pits were observed to form in the PEA/PS blend films and this degradation behavior was similar to that of the PEA material. Using these results, the domains in 70:30 blend were identified as the PS-rich regions and the matrix as the PEA-rich region. This conclusion is confirmed by FTIR-ATR analyses which revealed the hydrolysis of the PEA material. TMAFM phase imaging was also used to follow pit growth of the blend as a function of exposure time. The usefulness of the chemical modification/AFM imaging approach in understanding the degradation process of a coating film is discussed.
, Gu, X.
, Nguyen, T.
and VanLandingham, M.
Characterization of Chemical Heterogeneity in Polymer Systems Using Hydrolysis and Tapping Mode Atomic Force Microscopy, Journal of Polymer Science Part B-Polymer Physics, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=860312
(Accessed February 21, 2024)