Reptation moves, polymeric systems

Medium-to-high conversion The diffusion mechanism of the propagating radicals becomes complex after the onset of the gel effect. Large chains become immobile however, the chain ends may move by reptation or reaction diffusion. Monomer and short species may still be highly mobile in the polymerizing system. Translational center-of-mass diffusion may become the rate-determining step for radical-radical termination. 

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