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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).

Tracer methods have been used to analyse terpolymers formed in radical processes. The results have been used in an attempt to compare the reactivities of styrene, methyl methacrylate and methyl acrylate towards a polymer radical having a terminal maleic anhydride unit. Anomalous results are obtained in an application of the conventional treatment.

The stability of helical conformations in simple polymer chains should depend upon intramolecular interactions, which can be described in a first approximation in terms of repulsive forces between nonbonded atoms along the chain plus a small contribution from dispersion forces. Using the same consistent set of interaction parameters as in a previous work on small molecules, the conformational potential energy of isolated polymer chains satisfying the postulate of the conformational equivalence of each monomeric unit has been investigated as a continuous function of skeletal bond angles. The most stable conformations corresponding to the deepest minima of the potential energy plot for polyethylene, polytetrafluoroethylene, polyoxymethylene and polyethylene oxide are in good agreement with the conformations experimentally observed from X-ray diffraction patterns.