Features of the hedritic morphology of β-isotactic polypropylene studied by atomic force microscopy

The lamellar organization of melt-crystallized beta-isotactic polypropylene was studied by atomic force microscopy (AFM) after permanganic etching. Hedritic objects grown at a high crystallization temperature (140-143 degrees C) were investigated. Essential features of the hedritic development were revealed by the characteristic projections exposed at the sample surface. A three-dimensional view of the morphology was obtained by AFM. Hedritic growth proceeded mainly by branching around screw dislocations resulting in new lamellae that further developed. Successive lamellar layers often diverged. Deviation from the planar lamellar habit was observed, varying with the position within the hedrite. Twisting of the lamellae also was observed occasionally in the vicinity of the screw dislocations. (C) 2000 John Wiley & Sons, Inc.