Radiation-induced solid-phase polymerization. I. Polymerization of acrylonitrile

Journal Article · Tue Jan 01 04:00:00 EST 1963 · Journal of Polymer Science, Part C. Polymer Symposia

DOI:https://doi.org/10.1002/polc.5070040210· OSTI ID:4118380

Barkalov, I. M.; Goldanskiǐ, V. I.; Enikolopyan, N. S.; Terekhova, S. F.; Trofimova, G. M.

Radioinduced polymerization of solid and liquid acrylonitrile (AN) at - 196 to 0 deg C was studied. A diathermic calorimeter was used to determine whether polymerization takes place in the solid state during irradiation or during the subsequent heating. The presence of active centers during irradiation of AN at different temperatures and their disappearance after irradiation was detected by the ESR (electron spin resonance) method. Post-polymerization kinetics was studied as well. In AN at <-140 deg C (phase-transition point), solid-state polymerization took place only during irradiation. There was a certain limiting polymer yield, and no post-effects were observed in spite of persistence of the shape and intensity of the ESR signal after the end of irradiation. The activation energy of solidstate polymerization of AN was zero up to the melting point (-82 deg C). At temperatures greater than --140 deg C, the AN polymer yield in the solid state was no longer limited, and postpolymerization took place. Its activation energy ( approximates 3 kcal/ mole) was the same as for the polymerization in the liquid phase. Thus, the solid-state post-polymerization mechanism was similar to that of the liquid-state process, and differed from that of the solid-state polymerization during irradiation. These facts were considered evidence for specificity of radiation- induced solid-state polymerization during irradiation. The high efficiency of such polymerization was probably caused by the formation of short-lived excited molecular states. Such states decay soon after the end of the solid-state irradiation (although the ESR signal persists) and for the liquid phase their steady-state concentrations during the irradiation are much less due to increase in the quenching rate. Such active centers can be much more effective than ions or radicals in the energychain propagation of solid-state polymerization as suggested by Semenov. (auth)

• Research Organization: Inst. of Chemical Physics, Moscow
• Sponsoring Organization: USDOE
• NSA Number: NSA-18-012214
• OSTI ID: 4118380
• Journal Information: Journal of Polymer Science, Part C. Polymer Symposia, Journal Name: Journal of Polymer Science, Part C. Polymer Symposia Journal Issue: 2 Vol. 4; ISSN 0449-2994
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

ACRYLIC ACID
CALORIMETERS
CHEMICAL REACTIONS
CHEMISTRY
CONFIGURATION
CYANIDES
DIAGRAMS
EFFICIENCY
ELECTRON SPIN RESONANCE
ELECTRONS
ENERGY LEVELS
EXCITATION
FREE RADICALS
HEATING
IONS
IRRADIATION
LIFETIME
LIQUIDS
LOW TEMPERATURE
MAGNETIC RESONANCE
MEASURED VALUES
MELTING POINTS
MOLECULES
NITRILES
PERFORMANCE
PHASE DIAGRAMS
POLYESTERS
POLYMERIZATION
RADIATION CHEMISTRY
REACTION KINETICS
RESONANCE
SOLIDS
SPECTROSCOPY
SPIN
TEMPERATURE
THERMODYNAMICS
USES
VARIATIONS