- Author
-
Bain, D. R.
- Title
- Kinetics of Degradation of Some Polystyrenes and Copolymers of Styrene and Acrylonitrile. Summary Report. March 1970-September 1970,
- Coporate
- Air Force Materials Lab., Wright-Patterson AFB, OH
- Report
-
AFML-TR-71-132,
June 1971,
66 p.
- Distribution
- Available from National Technical Information Service
- Contract
- F33615-69-C-1385
- Keywords
-
kinetics
|
degradationpolystyrene
|
copolymers
|
styrenes
|
acrylonitriles
|
reaction kinetics
|
thermal degradation
|
thermogravimetry
|
activation energy
|
chemical chain reactions
|
chain breaking
|
temperature effects
|
chain breaking
|
chain reactions
|
weight loss
- Identifiers
- rate of weight loss and temperature data for the various polystyrene and copolymer samples studies; arrhenius data for the polystyrens and copolymers
- Abstract
- The kinetics of degradation of some polystyrenes and a series of copolymers of styrene and up to 33.4% acrylonitrile were studied by dynamic thermogravimetry in vacuum. An average activation energy of 42.5 k. cal was found for the entire series independent of composition. The primary effect of the acrylonitrile units is to increase the rate of chain scission and this effect is masked by the overall rapid initial rate of chain scission as the sample temperature is increased. Minor experimental abnormalities were responsible for sone variation in the Ea values but this was never more than ±2.5 k. cal. Some effects which could be attributed to differences in melt flow and subsequently on the contact between sample and thermocouple was visible in the Arrhenius plot but had no effect on the final Ea value.