Abstract
The rates of liquid-phase oxidation of n-dodecene with oxygen using benzoyl peroxide as initiator and the compositions of oxidation products have been studied.
At 120140°C the oxidation of n-dodecene was easier than that of n-dodecane, and the concentrations of hydroxyl, peroxide and carbonyl groups were large even at the beginning of the oxidations, but concentration of carboxyl group was gradually increased up to about 25 mole% of n-dodecene used. The concentration of ester group became lager with time, and only about 60% of C=C double bond was consumed. Accordingly, oxygen would attack not only C=C double bond and its α-methylene group but also to the other methylene groups. At above 160°C, random attack of oxygen occurred. However, the compositions of products, in which the concentration of carboxyl group became to 25 mole% of dodecene used, were constant between 120 and 160°C.
In the oxidation of dodecene-1, large amount of CO2, volatile acids and others were produced even at the beginning of oxidation. The liquid oxidaton products contained about 25 wt % of carboxylic acid and about 75 wt % of unsaponificable products containing α, β-unsaturated and saturated alcohols, ketones and aldehydes. Most of the carboxylic acids were keto-aids, hydroxyacids and polymeric acids. The unsubstituted fatty acid part contained large amount of lower fatty acids having less than six carbon atoms, and the compositions of higher acids were in the order of C8 ≈ C11 > C9 > C10.
When heavy metal salt was used together with benzoyl peroxide, the rate of formation of various groups was different from the case of benzoyl peroxide as the sole initiator.
