抄録
Chlorinated polyethylene (CPE) is usually produced in either solution or suspension phase. In order to study the behavior of photochlorination reaction and structural configuration of the obtained products, the radical chlorination reaction of polyethylene has been carried out in perchloroethylene as solvent, at atmospheric pressure and a temperature around 100°C. The photochlorination reaction was carried out via sparging of chlorine gas into the PE solution and exposing to the UV light. This PE solution consists of HDPE or LDPE dissolved in perchloroethylene solvent. Instrumental analyzing has been accomplished on the samples which have been taken in equal periods of time during the reaction. The recorded FTIR spectra of CPE's samples in comparison with the initial PE spectra indicate the gradual changes, which have been occurred at the polymer chains. The multiplications of methylene (CH2) groups of peaks and chloromethylene (CHCL) groups of peaks that appeared in the H-NMR spectra were characterized. The sequences of methylene units between two subsequent chloromethylene units in the polymeric chain have been determined from the H-NMR spectra and their results have bee verified with the data of some model compounds. The relative fractions of these methylene sequences have been plotted versus the concentration of chlorine. The procedure of variations of methylene sequences resulted from this curve also have been discussed. The chlorine percentage of each sample has been calculated from their H-NMR spectra base on the relative integrated value of methylene and chloromethylene group of peaks. The results of this quantitative analyzing have been confirmed with an elemental analyzing technique such as flask combustion method in a plot versus the reaction time. Finally the procedure of variations observed at reaction rate has been described.
