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Publication Citation: Characterization of Chemical Heterogeneity in Polymer Systems Using Hydrolysis and Tapping Mode Atomic Force Microscopy

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Author(s): D Ragahavan; X. Gu; Tinh T. Nguyen; Mark R. VanLandingham;
Title: Characterization of Chemical Heterogeneity in Polymer Systems Using Hydrolysis and Tapping Mode Atomic Force Microscopy
Published: July 01, 2001
Abstract: 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.
Citation: Journal of Polymer Science Part B-Polymer Physics
Volume: 39
Issue: No. 13
Pages: pp. 1460 - 1470
Keywords: AFM;building technology;chemical modification;coating;heterogeneity;hydrolysis;phase imaging;polymer
Research Areas: Building and Fire Research
PDF version: PDF Document Click here to retrieve PDF version of paper (373KB)