Preparation of functionally gradient materials via frontal polymerization
Ascending frontal polymerization in a body with a moving boundary was accomplished experimentally. This process was shown to be a steady-state process within a certain range of the parameters. Temperature profiles of the front were recorded. This new method gives an excellent opportunity to prepare functionally gradient materials because composition of a monomer feedstream can be varied in a programmable manner. Polymer samples with hyperbolic gradients of optical dye concentration were manufactured at ambient pressure and temperature. (C) 2000 John Wiley & Sons, Inc.