Stereoselective nucleophilic substitution of poly(vinyl chloride) with sodium thiophenate in cyclohexanone solution: Influence of the reaction temperature on the mechanism

The reaction was studied at 5,25,40,60 and 70°C. The initial rate obeys an Arrhenius law from 25 to 60°C, with an activation energy of 70 kJ/mol. Conversion limits are observed which strongly depend on the temperature. The stereoselectivity of the reaction with respect to the configurational triads does not depend on the temperature: the distribution of configurations is only dependent on the conversion. Assuming an S N 2 substitution mechanism governed by steric factors, the Monte Carlo simulation procedure described in a prior study is shown to give a good account for all temperatures above 40°C.