18665
PEG - P ( HEMA - co - AC ) copolymers were prepared with controlled Mn of 9 . 1 , 9 . 5 , and 9 . 9 kg / mol and varying numbers of AC units per molecule of 7 , 9 and 11 , respectively ( denoted as copolymer 1 , 2 , and 3 ) by reversible addition - fragmentation chain transfer copolymerization .
 Chemical: PEG - P ( HEMA - co - AC )
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 Chemical: PEG - P ( HEMA - co - AC )