Degradation of polymer/substrate interfaces – an attenuated total reflection Fourier transform infrared spectroscopy approach
- Suggests why eponol is used as an additive to paint.
- In this thesis, attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy has been used to detect changes at the interfaces between poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (PVB) and ZnSe upon exposure to ozone, humidity and UV-B light.
- Also, the response of PVB-aluminum interfaces to liquid water has been studied and compared with the same for eponol (epoxy resin, diglycidyl ether of bisphenol A)-aluminum interfaces.
- In the presence of ozone, humidity and UV-B radiation, an increase in carbonyl group intensity was observed at the PVB-ZnSe interface indicating structural degradation of the polymer near the interface. However, such changes were not observed when PVB coated ZnSe samples were exposed to moisture and UV-B light in the absence of ozone showing that ozone is responsible for the observed structural deterioration. Liquid water uptake kinetics for the degraded PVB monitored using ATR-FTIR indicated a degradation of the physical structural organization of the polymer film.
- Exposure of PVB coated aluminum thin film to de-ionized water showed water incorporation at the interface. There were evidences for polymer swelling, delamination and corrosion of the aluminum film under the polymer layer.
- On the contrary, delamination/swelling of the polymer was not observed at the eponol-aluminum interface, although water was still found to be incorporated at the interface. Al-O species were also observed to form beneath the polymer layer.
- A decrease of the C-H intensities was detected at the PVB-aluminum interface during the water uptake of the polymer, whereas an increase of the C-H intensities was observed for the eponol polymer under these conditions.
- This is assigned to rearrangement of the macromolecular polymer chains upon interaction with water.
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