Nodular Structure of Polypropylene

The size distribution of nodules on the surface of polypropylene films crystallized from the glass and subsequently annealed was studied. The origin of the nodule was the crystallite produced by the growth of many nuclei which were generated on crystallization from the glass and survived on annealing. The surviving nuclei grow until they collide with the neighbors. In this case, the size distribution of nodules is represented by that of Voronoi polygons. The agreement between observed and calculated ones is good.