A Kinetic Investigation on the Formation of Amorphous and Crystalline Polyethylidene from the Decomposition of Diazoethane in Ethyl Ether Using Gold as Catalyst

摘要

The kinetics of both amorphous and crystalline polyethylidene formation from the gold catalyzed decomposition of diazoethane in ethyl ether solutions was investigated. The results show that the rate of both amorphous and crystalline polyethylidene formation is proportional to the first power of the catalyst concentration and does not depend upon diazoethane concentration in the range of diazoethane concentrations between 0.04 and 0.3 moles/litre. Apparent energies of activation of 12 and 8 Kcal/mole were calculated for the processes leading to amorphous polyethylidene and to crystalline polyethylidene respectively. The degree of polymerization of the amorphous polyethylidene obtained from the gold catalyzed decomposition of ethyl ether solutions of diazoethane decreases with increasing the temperature of reaction as with increasing the concentration of the catalyst and of diazoethane. On the basis of the experimental results, some hypotheses upon the mechanism of the reactions leading to amorphous and crystalline polyalkylidenes from the metal catalyzed decompositions of diazoalkanes are drawn. (Author)