A kinetic study of the addition of the ethyl radical to acrylonitrile and its mono-methyl derivatives

• Main Author: Ogawa, Takeshi
• Language: English
• Published: University of British Columbia 2011
• Subjects: Chemical kinetics
• Online Access: http://hdl.handle.net/2429/38362

The kinetic study of the reactions, of the ethyl radical with the conjugated olefinic compounds has revealed the effect of various structual factors upon molecular reactivity. Acrylohitriie and its mono-methyl derivatives; cis- and trans-crotononitrile and methacrylonitrile were the substrates in this investigation. It was found that the addition of the ethyl radical to the C=C double bond was the most important reaction and that methathesis and addition to the CN triple bond could be neglected. Values for the energy of activation (E₇-½E₂) for cis- and trans-crotononitrile and methacrylonitrile were not distinguishable; 4.85 ±0.68, 4.69 ±0.96 and 4.61 ±0.67 respectively. The energy of activation for acrylonitrile for acrylonitrile was found to be 3.45 ±0.52. It appeared that the methyl group In cis- and trans-orotononitrile and in methacrylonitrile raised the energy of activation for addition from the value for acrylonitrile by about the same amount for each of the methyl derivatives. Simple correlations of the rate constants for the addition of the ethyl radical with the methyl affinities with various substrates, and with the monomer reactivity ratios for the copolymerization of various monomers with styrene were obtained. Copolymerizatlon reactions of cis- and trans-crotononitrile with styrene are also investigated and the polimerizability of these compounds is discussed. Some studies on the isomerization of cis- and trans- crotononitrile are also discussed. In this work, cis-croto-nonitrile was found to be thermally more stable than the trans isomer. === Science, Faculty of === Chemistry, Department of === Graduate