Studies on the reaction between ethylenic molecules and free radicals

Thomson, Ross A. M (1960) Studies on the reaction between ethylenic molecules and free radicals. PhD thesis, University of Glasgow.

Abstract

The photochemical reaction between vinyl acetate and bromotrichloromethane has been investigated dilatometrically. The propagation steps in the reaction are as follows:- The value obtained by previous workers for the velocity coefficient of reaction 3 indicated that under suitable concentration conditions, a measurable quantity of high polymer should be produced. On examination, however, no polymer was detected. It has been found that the ratio of the velocity coefficient for reaction 3 to the velocity coefficient for the addition of the radical produced by reaction 2 to a vinyl acetate molecule is sufficiently high to preclude the formation of polymer. A marked decrease in value has been found in the ratio of the velocity coefficient for chain transfer to the velocity coefficient for propagation with increase in radical DP for the chain transfer of bromotrichloromethane with vinyl acetate. The only apparent explanation of this is that bromotrichloromethane has a negative e-value in the Alfrey-Price Q-e Scheme. Velocity coefficients for the photochemical reaction between vinyl chloride and bromotrichloromethane have also been evaluated where possible. Results show that vinyl chloride and vinyl acetate are similarly reactive towards the trichloroethyl radical, which would be expected from co-polymerisation studies. The homogeneous and heterogeneous photo-sensitised polymerisations of vinyl chloride have been compared and close similarities lave been found to exist.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Adviser: W I Bengough
• Keywords: Physical chemistry, Molecular chemistry, Organic chemistry
• Date of Award: 1960
• Depositing User: Enlighten Team
• Unique ID: glathesis:1960-73516
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 14 Jun 2019 08:56
• Last Modified: 14 Jun 2019 08:56
• URI: https://theses.gla.ac.uk/id/eprint/73516