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Copolymerization of propylene with 1‐octene catalyzed by MgCl 2 /TiCl 4 /diether catalyst
Author(s) -
Bi Fuyong,
He Aihua,
Li Huayi,
Hu Youliang,
He Zhiyuan,
Han Charles C
Publication year - 2011
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.3100
Subject(s) - polymerization , catalysis , copolymer , polypropylene , natta , crystallinity , polymer chemistry , ziegler–natta catalyst , tacticity , materials science , chemical engineering , chemistry , organic chemistry , polymer , composite material , engineering
MgCl 2 /TiCl 4 /diether is a fifth‐generation Ziegler–Natta catalyst for the commercial polymerization of propylene. The outstanding features of this catalyst are the high activity and high isotacticity for propylene polymerization without using an external electron donor. In this study, we explored the copolymerization of propylene and 1‐octene with MgCl 2 /TiCl 4 /diether catalyst. It was found that MgCl 2 /TiCl 4 /diether catalyst showed higher polymerization activity and led to greater 1‐octene content incorporation, compared with a fourth‐generation Ziegler–Natta catalyst (MgCl 2 /TiCl 4 /diester). With an increase in 1‐octene incorporation in polypropylene chains, the melting temperature, glass transition temperature and crystallinity of the copolymers decreased distinctly. The microstructures of the copolymers were characterized using 13 C NMR spectroscopy, and the copolymer compositions and number‐average sequence lengths were calculated from the dyad concentration and distribution. This result is very important for the in‐reactor polyolefin alloying process, especially for the case of a single catalyst and two‐step (or two‐reactor) process. Copyright © 2011 Society of Chemical Industry