This paper deals with the mathematical modelling of the random scissio
n of branched chains. The objective is to predict the reaction product
s as well as the molecular weigth distribution for processes such as t
he chemical modification of polyolefins by free radical mechanism. In
comparison with linear chains, where the number of scission possibilit
ies is clear and scission products are linear, for branched chains the
problem is much more complex. Two modelling approaches for branched c
hains were used. The first one, a kinetic, deterministic approach assu
mes a simple, regular morphology for all chains in order to compute it
s effect on the process. The second, more realistic approach uses Mont
e Carlo methods, and is able to keep track of the structure of each ch
ain during the scission process. Stars and combs were used as idealize
d structures in the simulations with both approaches. The two approach
es are applied, compared and discussed. The simulated results show tha
t the chain morphology plays an important role in the scission of bran
ched chains.