Synthesis, Characterization and Applications of Late-Transition Metal Branched Polyethylene

Abstract:

The branched polyethylene (br-PE) was synthesized by [ArN=C(An)-C(An)=NAr]NiBr₂ (An = acenaphthyl, Ar = 2,6-C₆H₃(iPr)₂) in the presence of modified methylaluminoxane (MMAO) and methylaluminoxane (MAO). The effects of experimental conditions in which ethylene pressure, temperature and time were varied on ethylene polymerization were investigated. The structures of the obtained polyethylene were characterized by high-temperature NMR, high-temperature GPC and DSC. It was found that the activities from MMAO were higher than that from MAO about 10 times, which reaches 10⁷(g/mol Ni·h). The branches of polyethylene prepared from MMAO were about 60/1000C, while that from MAO were about 80/1000C. The branched polyethylene with 84 branches / 1000C was used to toughen isotactic polypropylene (i-PP). The results show that the impact strength of blends improves as the content of branched PE increases. When the content of br-PE is 40%, the impact strength of the blend reaches to 50.24 KJ/m², which is about twenty times that of PP (2.24 KJ/m²).

• Periodical: Advanced Materials Research (Volumes 1120-1121)
• Pages: 564-567
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1120-1121.564
• Online since: July 2015
• Authors: Wen Yu, Dan Feng Zhang*
• Keywords: Branched Polyethylene, Ethylene Polymerization, Late-Transition Metal Catalyst, Pp/Pe Blend

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