title: Analysis of Chain Branch of Polyolefins by a New Proton NMR Approach.
abstract: The crystallinity of polyethylene, which significantly affects the properties of the polymer, is quite sensitive to the concentration of its branches. Thus, it is necessary to estimate branch concentration with reasonable accuracy. Currently, (13)C NMR and gel permeation chromatography-Fourier transform infrared spectroscopy are widely-used analysis methods for the analysis of branch concentration. Despite several advantages, these methods sometimes have limitations. For instance, the preparation of samples for (13)C- NMR is tedious because high-concentration samples are required and the time for analysis is greater than 12 h. To more efficiently estimate the branch concentration of polyethylene, we developed a new high-field (1)H NMR method with an improved peak resolution by employing (1) homonuclear decoupling and (2) 2D heteronuclear correlation. The new method was observed to significantly reduce the experimental time to ∼ 30 min; furthermore, sample preparation was relatively simple because the method did not require high-concentration samples.
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.|Department of Biosystems & Biotechnology, Division of Biotechnology, Korea University , Seoul, 136-713, Republic of Korea.
authors.forename: Minhwan
authors.initials: M
authors.lastname: Jung
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.
authors.forename: Yura
authors.initials: Y
authors.lastname: Lee
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.
authors.forename: Sooyoung
authors.initials: S
authors.lastname: Kwak
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.
authors.forename: Heeyong
authors.initials: H
authors.lastname: Park
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.
authors.forename: Byoungsoo
authors.initials: B
authors.lastname: Kim
authors.affiliation: Department of Biosystems & Biotechnology, Division of Biotechnology, Korea University , Seoul, 136-713, Republic of Korea.
authors.forename: Sulhee
authors.initials: S
authors.lastname: Kim
authors.affiliation: Bruker Korea , 4F. KT Net Building, Pangyoro 338, Bundang-Gu, Seongnam-si, Gyeonggi-do 463-847, Republic of Korea.
authors.forename: Kwang Hwan
authors.initials: KH
authors.lastname: Lee
authors.affiliation: Corporate R&D, LG Chem Research Park , 104-1, Moonji-dong, Yuseung-gu, Daejeon, 305-380, Republic of Korea.
authors.forename: Hye Sung
authors.initials: HS
authors.lastname: Cho
authors.affiliation: Department of Biosystems & Biotechnology, Division of Biotechnology, Korea University , Seoul, 136-713, Republic of Korea.
authors.forename: Kwang Yeon
authors.initials: KY
authors.lastname: Hwang