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Highly Efficient Synthesis of Low Polydispersity Core Cross‐Linked Star Polymers by Ru‐Catalyzed Living Radical Polymerization
Author(s) -
Goh Tor Kit,
Yamashita Satoshi,
Satoh Kotaro,
Blencowe Anton,
Kamigaito Masami,
Qiao Greg G.
Publication year - 2011
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201000641
Subject(s) - dispersity , polymer chemistry , polymer , catalysis , polymerization , ethylene glycol , methyl methacrylate , ethylene glycol dimethacrylate , radical polymerization , materials science , context (archaeology) , chemistry , organic chemistry , methacrylic acid , paleontology , biology
The efficient formation of low polydispersity core cross‐linked star (CCS) polymers via controlled/living radical polymerization (LRP) and the arm‐first approach was found to be dependant on the mediating catalyst system. The Ru catalyst, Ru(Ind)Cl(PPh 3 ) 2 Cat. 1 , and tertiary amine co‐catalyst were used to synthesize highly living poly(methyl methacrylate) (PMMA) macroinitiators, which were then linked together with ethylene glycol dimethacrylate (EGDMA) to form PMMA arm PEGDMA core CCS polymers. The quantitative and near‐quantitative synthesis of CCS polymers were observed for low to moderate molecular weight macroinitiators ( $\overline {M} _{{\rm n}} $ = 8 and 20 kDa), respectively. Lower conversions were observed for high‐molecular weight macroinitiators ( $\overline {M} _{{\rm n}} $ ≥ 60 kDa). Overall, an improvement of between 10 and 20% was observed when comparing the Cat. 1 system to a conventional Cu‐catalyzed system. This significant improvement in macroinitiator‐to‐star conversion is explained in the context of catalyst system selection and CCS polymer formation.