OXIDATION OF 1,3-BUTADIENE

The liquid-phase oxidation of butadiene to explosive butadiene polyperoxide, (C4H6O2)]x, has been investigated to determine the effect of temperature, solvent, oxygen pressure, and catalysts on the rate of formation and structure of the product. The polyperoxide formed at 50° C. in the presence of more than 37 torr of oxygen is composed of equal amounts of 1,4- and 1,2-butadiene units separated by peroxide units. However, as the oxygen pressure is decreased below 37 torr at 50° C. the rate of reaction of butadiene, the structure, and the stability of the polyperoxide approach those of polybutadiene; at 2 torr of oxygen the ratio of butadiene units to peroxide units is about 2. The polymeric peroxide is the major product, only a few per cent of acrolein and butadiene-1,2-oxide being formed at lower oxygen pressures. The reaction is accelerated by increasing the temperature or adding free radical initiators. The 1-to-1 polyperoxide is only slightly soluble in butadiene and accumulates as a second phase during the oxidation of neat butadiene. © 1968, American Chemical Society. All rights reserved.