Effects of Sodium Salt and Sorbitol-Derivative Nucleating Agents on Physical Properties Related to Crystal Structure and Orientation of Polypropylene

Although various types of nucleating agents (NA) have been used in polypropylene (PP) for commercial products, the effects of sodium salt and sorbitol based NAs on polymer structures and the relation to the physical properties have been rarely reported. The present work reveals structure and orientation of PP crystal with direct comparison of two types of NAs, i.e., sodium salt and sorbitol-derivative, via X-ray scattering techniques. The results show how those crystal structures are related to the properties of injected-mold PP, with the emphasis on the compressive strength and shrinkage.