Type
Text
Type
Dissertation
Advisor
Clayton, Clive R | Halada, Gary | Fortmann, Charles | Wynne, James.
Date
2015-08-01
Keywords
Materials Science | Coatings, Composites, Degradation, Paint Stripping, Spectroscopy, Weathering
Department
Department of Materials Science and Engineering.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/76367
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Polymeric composites and coatings are commonly employed in outdoor applications where they are subject to degradation under environmental and service conditions. Numerous mechanical studies have related both UV exposure and thermal damage to a reduction in mechanical performance. Chemical studies have predominantly focused on degradation of matrix resins and coatings by UV and by thermal exposure, while ignoring the vulnerability of the fiber/matrix interphase in composites. Low-grade thermal exposure has provided early indications of further damage, but the mechanism has not been extensively studied. Coatings have been developed to resist chemical exposure but their chemical interactions with solvents used in their removal are not well understood. Research was undertaken by employing complementary vibrational and x-ray spectroscopic techniques to investigate the surface and bulk chemistries of selected polymeric systems in order to develop models for the effects of exposure. Carbon fiber / vinyl ester (CFVE) resin composites were studied to determine the chemical causes of the degradation in mechanical properties. The resin and composite systems were exposed to low-grade thermal damage and examined for chemical changes while also studying the mechanism of laser fluorescence as a means for early damage detection. Carbon fiber surface sizing was removed and analyzed in order to evaluate its stability against UV radiation, a known significant cause of mechanical degradation. The mechanism by which polyurethane coatings are degraded and removed from substrates by commonly used military paint stripper was determined in order to facilitate future development of a more environmentally-friendly formulation. Particular focus was given to the interactions of methylene chloride and phenol with vulnerable moieties of the polymer chain. Other components in the reference paint stripper were found to enhance the performance of these active solvents. A new model to describe solvent-coating interactions was developed. | 227 pages
Recommended Citation
Young, Christopher Norman, "Surface and Interfacial Study of Chemical Degradation in Polymer Composites and Coatings" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 2291.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/2291