Butadiene, absolute rate constants

Atkinson, R., Pitts, J.N., Jr. (1977b) Absolute rate constants for the reaction of oxygen (3P) atoms with allene, 1,3-butadiene and vinyl methyl ether over temperature range 297 -39 K. J. Phys. Chem. 67, 2492-2495. 

TABLE 4. Absolute rate constants for reaction of l,3,5-(l-sila)hexatriene 21a51, 2-trimethylsilyl-methyl-l,l-dimethylsilene (23)53, l,3-(2-sila)butadiene 2453 and 1-silaallene 26a55 in hexane or acetonitrile solution at 23-25°C... 

TABLE 19. Absolute rate constants (in units of 108 M s 1) for reaction of 103, 104 and 35 with 2,3-dimethyl-l,3-butadiene, oxygen and aliphatic ketones in hexane solution at 22- 25 °C... 

The absolute rate constants of radical addition to butadiene are 1.25x10 sec l for methyl (26) and 4.0x10 sec for trifluoromethyl (19) both in aqueous solution. These values are of the same order of magnitude as estimated for additions to nitrones in benzene. 

ABSOLUTE RATE CONSTANTS FOR BUTADIENE, ISOPRENE AHD DMBD... 

Equation (5) or (5b) is the highly important deduction of Harkins-Smith-Ewart theory. Its validity has been fully confirmed for many cases of polymerization (19). Furthermore, although it is difficult to determine the nvimber of particles, Np, accurately (19) this simple relationship has been used to determine the absolute value of the rate constant, kp, satisfactorily for the polymerization of butadiene and isoprene by Smith (20) and by Morton et al.(21). Conditions where the rate of polymerization is not proportional to the number of particles are where Trommsdorff s effect (22-24) or Gordon s unsteady state (25) principles apply. However, the existence of linear portions of the conversion-time plots proves the absence of these principles in this system. 

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