title: Crystallization of a polypropylene terpolymer made by a Ziegler-Natta catalyst: formation of gamma-phase.
abstract: The appearance of the gamma phase of a polypropylene-containing terpolymer prepared with a Ziegler-Natta catalyst was analyzed, and a novel strategy to make a polypropylene terpolymer which contains a high content of the gamma phase was experimentally sought. Wide-angle X-ray scattering and differential scanning calorimetry measurements have been conducted to investigate gamma-phase formation. Using a mixed flow of both elongational and shear components (a foaming process), we could introduce a lot of nuclei in the melt by flow-induced crystallization (FIC). The large number of nuclei accounting for the structural disorder during crystallite formation was ascribed to be the reason for gamma-phase formation in the terpolymer crystallization. A uniform distribution of defects in the melt crystallization was the key to obtaining a high content of the gamma phase.
authors: Polymer Hybrid Research Center, Korea Institute of Science and Technology, P.O. Box 131, Cheongryang, Seoul, Korea.
authors: Soon Man
authors: SM
authors: Hong
authors: Yongsok
authors: Y
authors: Seo
mesh_terms: D002073:Butanes / Q000138:chemical synthesis / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D002384:Catalysis; D003460:Crystallization; D008970:Molecular Weight; D011126:Polypropylenes / Q000138:chemical synthesis / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D002073:Butanes; D011126:Polypropylenes; C520883:poly(propylene-co-ethylene-co-1-butene)