Structural characterization of α- and β-nucleated isotactic polypropylene

Modification of isotactic polypropylene (iPP) with two nucleation agents, namely 1,3:24-bis(3,4-dimethylobenzylideno) sorbitol (DMDBS) (alpha-nucleator) and N, N'-dicyclohexylo-2,6-naphthaleno dicarboxy amide (NJ) (beta-nucleator), leads to significant changes of the structure, morphology and properties. Both nucleating agents cause an increase in the crystallization temperature. The efficiency determined in a self-nucleation test is 73.4% for DMDBS and 55.9% for NJ. The modification with NJ induces the creation of the hexagonal beta-form of iPP. The addition of DMDBS lowers the haze of iPP while the presence of NJ increases the haze. (C) 2004 Society of Chemical Industry.