USING ESCA AND SIMS IN COMPOSITES MANUFACTURING

摘要

The surface analysis techniques of electron spectroscopy for chemical analysis (ESCA) and secondary ion mass spectroscopy (SIMS) are shown to be indispensable analytical tools for identifying the chemical composition of bonding surfaces used in fiber-reinforced composites manufacturing. Composite plys are typically handled in clean rooms. Contaminated tabletop surfaces in a clean room can transfer the contaminant to the plys and result in poor composite adhesion. Extruded polyurethane has been used to cover these tabletops. An example of surface analysis is given by examining the surface contamination of an old, used tabletop by different methods and comparing that with the analysis of a new, clean tabletop. ESCA measurements on used tabletop surfaces found these surfaces to be contaminated with polydimethylsiloxane (PDMS) contamination. The presence of PDMS contamination was verified by SIMS analyses. The ESCA and SIMS analysis confirmed polyurethane was the base material and SIMS also detected a phthalate component. Energy dispersive x-ray microanalysis (EDX) and x-ray fluorescence analysis (XRF) were used to determine bulk elemental chemical composition of the polyurethane used in the tabletop. Fourier transform infrared spectroscopy (FTIR) of the polyurethane and of the collected volatile condensable material (CVCM) extracted from the total mass loss (TML) experiment conducted on the polyurethane agreed with the EDX data and showed that the bulk material used in the tabletops did not contain PDMS. The FTIR of the condensate showed that a phthalate plasticizer was also present in the bulk. EDX detected trace Si at extremely low concentrations, relative to the bulk. However, the EDX analysis was not able to establish the functionality of the Si. Thus, XRF, FTIR and TML-CVCM were not sensitive to the surface contaminant that ESCA and SIMS were able to detect. Finally, ESCA experiments conducted on new tabletop material did not detect any PDMS contamination.