Thermal Oxidation of Formaldehyde

Abstract

CARRUTHERS and Norrish¹ have observed that the polymerisation of formaldehyde is induced by formic acid, produced in the photochemical oxidation. An induced polymerisation apparently accompanied by an induced decomposition occurs in the thermal oxidation, at temperatures as high as 317°. This reaction possesses many features of interest from the point of view of the theory of chain reactions. Direct analysis has shown that the rate changes with time as predicted by the theory for chains with degenerate branching². Furthermore, in a series of mixtures, the initial rate depends on the third power of the formaldehyde concentration and is independent of oxygen concentration down to pressures of a few millimetres. In a single experiment, however, these conditions do not hold good, and with a sufficiently high initial velocity, good unimolecular constants can be obtained over a large range.