THE RADIATION-INDUCED POLYMERIZATION OF $alpha$-METHYLSTYRENE

Journal Article · Mon Jan 01 04:00:00 EST 1962 · Transactions of the Faraday Society (England) Superseded by J. Chem. Soc., Faraday Trans., I and II

DOI:https://doi.org/10.1039/tf9625800192· OSTI ID:4808198

Best, J V.F.; Bates, T H; Williams, T F

A kinetic study of the polymerization of alpha -methylstyrene initiated by cobalt-60 gamma rays is described. Using dry monomer at 30 deg C, the mean initial yield corresponds to the conversion of 8000 molecules per l00 ev; the rate accelerates with increasing polymer formation and ihe polymerization proceeds almost to completion. A decrease in dose rate brings about a higher rate of polymerization per unit dose. At 0 to 30- deg C, there is a slight increase of rate as the temperature is lowered; at 55 deg C the rate is considerably reduced. The addition of water in concentrations above 0.002 M to the systera results in a very strong retardation of the rate by coraparison with the dry reaction. While the molecular weight of the polyraer depends on the extent of monomer conversion, with M/sub n/, between l900 and 5100, it is only slightly affected by the presence of water in the polymerizing medium. The occurrence of facile chain transfer to monomer and the marked effect of water on the reaction rate are interpreted as evidence in favor of an ionic mechanism. It is proposed that water interferes mainly in the primary act leading to a suppression of the ionic initiator before propagation can ensue. (auth)

• Research Organization: Atomic Energy Research Establishment, Harwell, Berks, Eng.
• NSA Number: NSA-16-011739
• OSTI ID: 4808198
• Journal Information: Transactions of the Faraday Society (England) Superseded by J. Chem. Soc., Faraday Trans., I and II, Journal Name: Transactions of the Faraday Society (England) Superseded by J. Chem. Soc., Faraday Trans., I and II Vol. Vol: 58; ISSN TFSOA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
COBALT
GAMMA SOURCES
ISOMERS
METHYL RADICALS
POLYMERIZATION
QUANTITY RATIO
RADIATION CHEMISTRY
REACTION KINETICS
TEMPERATURE
WATER
WEIGHT