Compatibilization of i PP/HDPE Blends with PE- g- i PP Graft Copolymers

Kristine Klimovica; Sanshui Pan; Ting-Wei Lin; Xiayu Peng; Christopher J Ellison; Anne M LaPointe; Frank S Bates; Geoffrey W Coates

doi:10.1021/acsmacrolett.0c00339

Compatibilization of i PP/HDPE Blends with PE- g- i PP Graft Copolymers

ACS Macro Lett. 2020 Aug 18;9(8):1161-1166. doi: 10.1021/acsmacrolett.0c00339. Epub 2020 Jul 29.

Authors

Kristine Klimovica¹, Sanshui Pan², Ting-Wei Lin¹, Xiayu Peng², Christopher J Ellison², Anne M LaPointe¹, Frank S Bates², Geoffrey W Coates¹

Affiliations

¹ Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, United States.
² Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455, United States.

PMID: 35653207
DOI: 10.1021/acsmacrolett.0c00339

Abstract

The compatibilization of polyethylene (PE) and isotactic polypropylene (iPP) blends is of particular interest due to the challenges associated with recycling these plastics from mixed waste streams. Polyethylene-graft-iPP copolymers (PE-g-iPP) were prepared using a grafting-through strategy by copolymerization of ethylene with allyl-terminated iPP macromonomers in the presence of a hafnium pyridylamido catalyst. Graft copolymers with a variety of graft lengths (M_n = 6-28 kg/mol), graft numbers, and graft spacings were prepared. These graft copolymers were melt-blended with high-density polyethylene (HDPE) and iPP (iPP/HDPE = 30/70 w/w), and the blend properties were evaluated by tensile testing. The blends showed enhanced tensile strength at 5 and 1 wt % loading, with higher tensile strength observed for larger block numbers and graft lengths. These results indicate that graft copolymers are efficient compatibilizers for blends of HDPE and iPP.