Charge decay properties of poly(propylene) samples (PP) with various stereochemical compositions

Charge decay properties at 90 degrees C have been studied for four poly(pro pylene) (PP) samples of different content of isotactic (mm), syndiotactic ( rr) and heterotactic (mr, rm) triads. Comparing the charge decay properties with the previously measured space charge distribution and taking into acc ount the specific stereochemical sequences which characterize each of the s amples, it is apparent that mmrm and rrrm sequences furnish better storage properties. In contrast, mmrr and short heterotactic sequences would both e xhibit worse retention power of negative and positive charge.