1. University of Dayton Research Institute, Dayton, Ohio 45469-0168, Department of Polymer Science, University of Akron, Akron, Ohio 44325, Department of Industrial Chemistry, Chungbuk National University, Chungbuk, 361-763, South Korea, and Polymer Branch, AFRL/MLBP, Materials & Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433-7750