ON CELLULATION IN POLYETHYLENE SPHERULITES

Cellulation has been observed to develop with increasing radial distan ce within growing spherulites of a series of metallocene-catalyzed, et hyl-branched polyethylenes with branch contents ranging from 14 to 37 per 1000 main chain C atoms. The radius to the onset of cellulation an d the cell width are both sensibly constant for the same polymer and i ndependent of growth rate. For different polymers, both these quantiti es fall with increasing branch content. The implications of these nove l findings for the crystallization of polymers are discussed.