The Effect of Poisson Broadening

The first simulations with chain-length dependent termination rate coefficients were performed assuming no transfer to monomer and again only radical formation as a result of the laser pulse. The only physical process that can now undermine the assumption of a monodisperse radical distribution is the well known Poisson broadening of propagation reaction (initiator decomposition was assumed to be instantaneous). As already mentioned above, this effect can be tested very simply as by using a set of differential equations to describe the kinetics of this system, a Poisson distribution of these processes is automatically introduced [34, 38], This broadening process was thus actually already present in the previous set of simulations, but was not reflected in the kinetics because of the constant value of kt that was used in those calculations. 

Symbols represent the results of the computer simulations, while the lines are the corresponding input values. 

In conclusion it can be said that the Poisson distribution of the polymerization events does not significantly interfere with the monodispersity assumption needed for the accurate determination of kf. Even in the worst-case scenario (strong chain-length dependence) a truly negligible effect is introduced. In a recent simulation study of PLP by Olaj et al. [59] a similar conclusion was reached for the determination of kp. 

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