- Author
- Kashiwagi, T. | Omori, A. | Nanbu, H.
- Title
- Effects of Melt Viscosity and Thermal Stability on Polymer Gasification.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Journal
- Combustion and Flame, Vol. 81, No. 2, 188-201, 1990
- Keywords
- gasification | viscosity | thermal stability | melting | surface temperature | polymethyl methacrylate | exposure time
- Abstract
- The effects of melt viscosity and thermal stability of a polymeric material on gasification rate under external radiant fluxes from 1.7 to 3.9 W/cm2 are studied. The effects of melt viscosity are determined by using two different initial molecular weight polystyrene (PS) samples (about a factor of 2 difference in molecular weight); the combined effects of thermal stability with melt viscosity are determined by using two different initial molecular weight poly(methylmethacrylate) (PMMA) samples (about a factor of 4 difference in molecular weight). The results show that thermal stability affects gasification rate but that the transport process of the in-depth degradation products through the molten polymer to the sample surface does not significantly affect gasification rate except at low external radiant flux. The global heat of gasification is sensitive enough to differentiate the effects of thermal stability of the sample, but its value also depends on external radiant flux; in addition, it decreases with an increase in exposure time. This indicates that the global heat of gasification is not a unique quantity for a polymeric material.