Prediction of Sol Fraction and Average Molecular Weights after Gelation for Non‐Linear Free Radical Polymerizations Using a Kinetic Approach

Mass balance equations in terms of the moment generating function of the distribution of mole concentrations of polymer species for free radical copolymerizations of mono/divinyl monomers could be numerically solved after gel point using open source code ACDC, needed for extremely stiff two‐point boundary value problems. For the first time, it became possible to compare the error of earlier well‐known approximated estimation methods for the weight fraction of sol and average molecular weights to this accurate mathematical solution. It turns out that predictions by the pseudo‐kinetic method are reasonable only when equal reactivity of double bonds prevails, causing early gelation in the batch reactor. Otherwise the discrepancies between the exact and approximate solutions are quite important.

Comparison between predicted number‐average and weight‐average degrees of polymerization of sol in batch non‐linear free radical polymerizations of model system III.