Radical chlorination of polyethylene and molecular structure characterization of reaction products

Abstract

In this research the radical chlorination reaction of polyethylene has been carried out in perchloroethylene solvent under atmospheric pressure, using chlorine gas and UV light. In order to characterize the structural configuration of chlorinated polymer and study the reaction rate, different samples have been taken in equal periods of time during the reaction time. The FT-IR and H NMR spectra of these samples have been recorded and interpreted. The sequences of methylene groups between two subsequent chloromethylene groups in the polymeric chains have been determined through H NMR spectra and the obtained results have been confirmed with the data of some model compounds. The relative percentage of these methylene groups, which have been calculated from their integrated values in their H NMR spectra have been plotted vs. percentage of chlorination and discussed. Also H NMR spectra have been used for calculating the chlorine percentage of each sample and the results have been compared with data obtained from an elemental analyzing technique namely flask combustion method. Using the results of these two techniques, the reaction rate has been plotted versus reaction time and compared.