to break via the polymer scission mechanism, yet this is disallowed in our way of implementation of reaction schemes. The reason is that in our final analysis we set the limit of $k_f^- \rightarrow 0$, justifying our approximation. Lastly, in the eleventh term, i.e., polymer scission term, the lower limit $i+n_c$ makes sure that two fragments post-scission are stable polymers of size greater than or equal to $n_c$. The condition of the conservation of mass finally results into a time-dependent equation for the monomers \[eq3\] = -( \_[i=n\_c]{}\^ i y\_i(t) ).

Eq. \[eq2\] is different from previously obtained master equations on account of the additional terms that describe the contribution of the body evaporation $\kmb$ and addition $\kpb$. [@cohen; @hong] We also implement the *scission and recombination* pathway to allow for polymer fragmentation resulting only into fragments greater than or equal to the critical size; the recombining polymers also have to be of the size $i \ge n_c$. The reason for this is that we assume that any fragment of size $l \le n_c$ is highly unstable and quickly disintegrates to $l$ monomers. This prohibits the recombination of fragments smaller than the critical nucleus, as they do not exist in 