Simultaneously Chemically Reacting and Physically Relaxing Polymers

The work done in this research effort were:( a) An unambiguous experimental demonstration of the trajectory between creep curves exhibited by a sample subjected to an increment of crosslinking; (b) A clear demonstration that the time crosslink density reduction principal is generally applicable to crosslinked polymer systems but that the specific quantitative aspects of the shifting procedures depend very sensitively on the network topology involved in changing the crosslink density of the material; (c) The development of a kinetic theory of glass transition phenomenon and its extension to encompass physical aging of polymers; (d) A critical test of the damped Debye lattice model for relaxation in the primary transition region in which the model survived the test. Keywords: Accelerated aging tests; Stress relaxation. Also available as Rept. nos. ARO-16662.9-CH and ARO-19093.7-CH. Sponsored in part by contracts DAAG29-79-C-0167, DAAG29-82-K-0121 and Grant DAAG29-76-G-0194.