Abstract
Thermal decomposition of maleic anhydride in liquid phase has been studied at 200°C in a closed system under the atomosphere of nitrogen. Carbon dioxide, carbon monoxide, acety- lene, and ethylene were generated in the course of the reaction and the generation rates of these gases were about 5 × 10-2, 5 × 10-3, 8 × 10-5 and 3 × 10-5 mol%/hr, respectively. The kind of these gaseous products was the same as that obtained by the thermal decomposition in gas phase, but the product distribution was very much different. The low polymer was obtained after removing the unreacted maleic anhydride from the reaction mixture and was confirmed to undergo the thermal decomposition to give almost the same amount of CO2 observed in thermal decomposition of maleic anhydride (Fig. 1).
Taking these facts into consideration, the reaction scheme for the thermal decomposition of maleic anhydride in liquid phase and the structure (Fig. 3) of the low polymer obtained were proposed.
