TRACER TECHNIQUES FOR THE DETERMINATION OF MONOMER REACTIVITY RATIOS. IV. MONOMER REACTIVITY RATIOS FOR STYRENE-ISOPRENE COPOLYMERIZATION
The ionization chamber-vibrating reed electrometer assay technique was improved in precision ( plus or minus 0.25% average deviation) and used to determine monomer reactivity ratios for the styrene-- isoprene copolymerization. Values of r/sub 1/ (styrene) = 0.50 (100 deg ) and 0.54 (80 deg ) and r/sub 2/ = 1.92 (100 and 80 deg ) were obtained for the radical initiated copolymerization. For gamma -irradiation initiation at 22 deg , r/sub 1/ = 0.66 and r/sub 2/ == 1.88. For butyllithium initiation, r/sub 1/ = 0.03 and r/sub 2/ = 5.9. The difference in the radical and gamma -radiation initiation values is considered in terms of possible partial ionic character of the radiation initiation process and possible temperature dependence of the reactivity ratios (r/sub 1/) over the 22 to 100 deg C range. The latter indicates a difference in activation energy of 0.8 kcal/mole for the radical to styrene and radical to isoprene propagation steps. (auth)
- Research Organization:
- Univ. of Louisville, Ky.
- NSA Number:
- NSA-17-034015
- OSTI ID:
- 4657302
- Journal Information:
- J. Polymer Sci., Pt. A, Journal Name: J. Polymer Sci., Pt. A Vol. Vol: 1
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
Simple and Accurate Determination of Reactivity Ratios Using a Nonterminal Model of Chain Copolymerization
Copolymerization of styrene with isobutyl vinyl ether by radiation
Related Subjects
BUTYL RADICALS
CATALYSIS
CHEMICAL REACTIONS
CHEMISTRY
ELECTROMETERS
ENERGY LEVELS
ERRORS
EXCITATION
FREE RADICALS
GAMMA RADIATION
INSTRUMENTS
IONIZATION
IONIZATION CHAMBERS
IONS
ISOPRENE
LITHIUM COMPOUNDS
MEASURED VALUES
METHYL RADICALS
MOLECULES
ORGANOMETALLICS
PERFORMANCE
POLYMERIZATION
POLYMERS
POLYSTYRENE
REACTION KINETICS
STYRENE
TEMPERATURE
TRACER TECHNIQUES
USES