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Molecular weight studies have been made of the bulk polymerization of vinyl chloride initiated by borontriethyl-oxygen and by borontriethyl-cumylhydroperoxide at temperatures between − 40° and + 20°. The molecular weight increases with conversion until a constant value is obtained. This behaviour is ascribed to a decrease in the concentration of the initiating radicals with time and to the existence of transfer reactions. As a further explanation of the increase in the molecular weight, variation of the ratio t/kp2 during the polymerization is suggested.

The esterifications of terephthalic acid and monomethylterephthalate with methanol have been studied in order to compare the reaction rate constants of the first and second carboxyl groups of terephthalic acid. The ratio of the two constants is found to be 1 · 18 ± 0 · 07 at 110°. A value of the Hammett substituent constant for the group COOCH3 at the para position is reported (σCOOCH3 = 0 · 59).