title: Degradation behavior of polymer blend of isotactic polypropylenes with and without unsaturated chain end group.
abstract: In this work, the relationship between the unsaturated chain end group content and the thermal oxidative degradation rate was systematically studied with binary polymer blends of isotactic polypropylene (iPP) with and without the unsaturated chain end group. The iPPs with and without the unsaturated chain end group were synthesized by a metallocene catalyst in the absence of hydrogen and by a Ziegler catalyst in the presence of one, respectively. The thermal oxidative degradation rate of the binary iPP blends was estimated from the molecular weight and the apparent activation energy (ΔE), which were obtained through size exclusion chromatography (SEC) and thermogravimetric analysis (TGA) measurements, respectively. These values exhibited a negative correlation against the mole content of the unsaturated chain end group. The thermal oxidative degradation rate apparently depends on the content of the unsaturated chain end group. This tendency suggests that the unsaturated chain end acts as a radical initiator of the iPP degradation reaction.
authors.affiliation: Department of Applied and Environmental Chemistry, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido, 090-8507, Japan.
authors.forename: Hisayuki
authors.initials: H
authors.lastname: Nakatani
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors.forename: Dodik
authors.initials: D
authors.lastname: Kurniawan
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Taniike
authors.affiliation: School of Materials Science, Japan Advanced Institute of Science and Technology, 1-1 Asahidai, Nomi, Ishikawa, 923-1292, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Terano
keywords: activation energy; polypropylene; radical initiator; unsaturated chain end groups