Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
Chemistry and Pharmacology
Radiation-induced copolymerization of acrylonitrile with styrene was carried out over a wide range of temperatures. It was found that the rate of copolymerization is proportional to the square root of the dose rate. An apparent activation energy of 6.90 kcal./mole was obtained for the copolymerization in an equimolar mixture of monomers. The rate of copolymerization increased with the molar concentration of acrylonitrile in the monomer mixture. Monomer reactivity ratios were determined as rAN = 0.03, rSt = 0.33 for the copolymerization at 15 and 0°C., rAN = 0.28, rSt = 0 at -20°C. in the liquid state of monomers. On the other hand, the monomer reactivity ratios were obtained as rAN ≃ 0 and rSt ≃ 0 for the copolymerization in the solid state at -78°C. It was concluded from these experimental results that there is a great difference between the liquid-state and solid-state copolymerizations, both in the polymerization mechanism and the structure of copolymers.
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