Kinetics of free radical decay reactions in irradiated isotactic polypropylene. [Gamma rays]

Journal Article · Thu May 28 04:00:00 EDT 1981 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150611a021· OSTI ID:6205425

Gvozdic, N; Basheer, R; Mehta, M; Dole, M

The kinetics of free radical decay reactions above and below the glass transition in isotactic polypropylene have been investigated for the decay reactions occurring both in a vacuum and in the presence of 550 torr of hydrogen gas. As expected the decay rate in vacuo is less below T/sub g/ at -26/sup 0/C than above T/sub g/ at -4/sup 0/C. Hydrogen markedly catalyzes the free radical decay at -4/sup 0/C, but less so at -26/sup 0/C, as expected because of the reduced hydrogen solubility at that temperature. The decay follows neither simple first-order nor second-order kinetics, nor is the decay a composite first-order reaction in contrast to the alkyl radical decay kinetics in bulk polyethylene. Instead, the data can be accurately represented by a new kinetic equation derived on the assumptions of a fraction of the initial free radicals decaying by a second-order mechanism and the remainder being converted by a first-order process into an identical free radical but in a location where it cannot react further.

• Research Organization: Baylor Univ., Waco, TX
• OSTI ID: 6205425
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:11; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMISTRY
DATA
DECAY
ELECTROMAGNETIC RADIATION
ELEMENTS
EXPERIMENTAL DATA
GAMMA RADIATION
HYDROGEN
INFORMATION
IONIZING RADIATIONS
KINETICS
LOW PRESSURE
LOW TEMPERATURE
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC POLYMERS
POLYMERS
POLYOLEFINS
POLYPROPYLENE
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADICALS
REACTION KINETICS