1. a Department of Macromolecular Science , Case Western Reserve University , Cleveland, Ohio, 44106
2. c Raychem Corporation , 300 Constitution Drive, Menlo Park, Calif, 94024
3. d Polymer Group , University of Illinois , III., Urbana, 61801
4. b Diamond Shamrock Corporation , P.O. Box 348, Painesville, Ohio, 44077