On the existence of near-range order in isotactic polypropylenes

Abstract

A form of polypropylene, intermediate between amorphous and crystalline, has been detected and studied by means of X-ray scattering, i.r. absorption, n.m.r. absorption, dynamic mechanical, and volumetric measurements. This form (called non-crystalline) is characterized as being an aggregation of molecules (or segments of molecules) in which portions of the individual chains maintain the helical structure found in the crystal but in which there is little, or no, lateral order sufficient to be called crystalline.