A review of modeling of diffusion controlled polymerization reactions

A plethora of models have been developed quantifying the effect of diffusion-controlled phenomena on polymerization reactions. The most prominent approaches are reviewed here, including innovative ones that have emerged over the last decade. Free-radical and step-growth polymerizations are considered in a way to show that similar models have been used in both mechanisms. In free-radical polymerization the models proposed are subdivided according to their theoretical background into four categories: (i) based on a Fickian description of reactant diffusion; (ii) free-volume theory based; (iii) chain-length dependent; and, (iv) empirical. The reversible addition-fragmentation technique is discussed, together with two industrially important case-studies, solid state polycondensation and epoxy-amine curing.