Frontal Polymerization as an Analog of Gasless Combustion

Thursday, September 30, 1999 - 2:00pm - 2:30pm
Keller 3-180
Vladimir Volpert (Northwestern University)
Frontal polymerization (FP) is a process in which a spatially localized reaction zone propagates into a monomer, converting it into a polymer. In many cases polymerization processes are exothermic, and the mechanism of propagation of such polymerization waves resembles that in combustion waves. Moreover, the methods developed in combustion theory have proven to be useful in studying FP problems. The FP process is currently under investigation as a novel method to produce polymers.

We develop and study mathematical models of free radical FP. The basic adiabatic model accounts for decomposition of the initiator, and initiation, growth and termination of polymer radicals as well as for heat conduction in the medium. We determine the structure of the polymerization wave and its propagation velocity as well as their dependence on the parameters of the problem. The nonadiabatic model determines the limits of propagation of the FP waves. We determined new mechanisms that affect extinction that have not been observed in simple combustion problems. Other models are also considered.

Our analytic results are in good quantitative agreement with both numerical simulations of the model and experimental data.