Surface Chemical Composition - Depth Profile of Polyether Polyurethaneureas as Studied by FT-IR and ESCA.
Abstract
Chemical composition-depth profile in the range covering 100 A to 2 micron was obtained with well-characterized polyether poly(urethaneurea) elastomers by combining FT-IR internal reflection technique with ESCA. In FT-IR technique, either the incident angle of the internal reflection attachment was changed or a thin film, which is transparent to most of IR radiation, was cast directly on the reflection plate to reduce the depth of the IR beam penetration in order to obtain surface chemical composition at various depths. Our results show that the flexible, soft segment is more abundant on the surfaces, especially at the air facing surface, as compared with the bulk composition. This trend is observed not only in the first 100 A, but also into a much deeper depth, such as 1 micron. Our results suggest that the migration of oligomers (approximately 5000 MW) such as trimers or pentamers, which have soft segments at both ends is responsible for the observed high content of soft segment on the surface. The presence of the oligomers are indicated by GPC and the extraction studies support that they have higher content of soft segment when compared with the bulk composition. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1979
- Accession Number
- ADA078240
Entities
People
- C. B. Hu
- C. S. Paik Sung
Organizations
- Massachusetts Institute of Technology