Study of Silica‐Supported Chromocene Catalysts for Ethylene Polymerization. Issue 17 (7th August 2020)

• Record Type: Journal Article
• Authors: Wang, Kai; Gao, Yuli; Yi, Jianjun; Zhao, Ning; Jin, Yulong; He, Xuelian; Liu, Boping
• Is Part Of: Macromolecular chemistry and physics. Volume 221:Issue 17(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-07
• Subjects: chromocene -- hydrogen response -- ultrahigh molecular‐weight polyethylene; Polymers -- Periodicals; Polymerization -- Periodicals; Synthetic products -- Periodicals; Macromolecules -- Periodicals; 547.7
• DOI: 10.1002/macp.202000181
• Languages: English
• ISSNs: 1022-1352

Abstract

Abstract: Ultrahigh molecular weight polyethylene (UHMWPE) has drawn great interest from researchers because it possesses many excellent properties such as superb strength and impact resistance, which other polyolefin cannot achieve. A silica‐supported chromocene catalyst, for the production of UHMWPE, is successfully developed. The polyethylene (PE) produced by the chromocene catalyst can achieve a molecular weight (MW) of over 3 × 10 6 g mol −1 with narrow molecular weight distribution (MWD) a value of approximately three. The activity calculated by Cr per unit reaches the maximum when the loading of Cr is 1.7 wt%. With the increasing loading of chromocene, the MW shows a small increase and the MWD becomes narrower. The chromocene catalyst for ethylene polymerization also shows a significant hydrogen response. With 0.01 MPa hydrogen added into the ethylene polymerization, the MW of the PE decreases immensely to only 0.7 × 10 6 g mol −1 and the MWD is broadened from <3 to ≈12. If the amount of hydrogen increases, the MW continues to decrease and the MWD becomes wider. The MW of the PE produced by the chromocene catalyst can be regulated easily by adjusting the amount of hydrogen. Abstract : A SiO2 ‐supported chromocene catalyst for producing Ultra‐high molecular weight polyethylene (UHMWPE) is studied. The polyethylene (PE) produced by the chromocene catalyst can achieve a molecular weight (MW) over 3 × 10 6 g mol −1 with narrow molecular weight distribution (MWD). Through changing the polymerization temperature and the loading of chromocene, the activity, the MW and the MWD are influenced.