Macromonomers with general formula C-n [EO](m)-CO-CH=CH2 were synthesized by endcapping corresponding Brij compounds with acryloyl chloride, Their aggregation behavior evaluated against the parent Brij compounds, the saturated and triblock analogs advocate that the terminal double bond is protected by the partially looped PEG chain. The homo- and copolymerization behavior in aqueous media is consistent with this possibility.