Synthesis and properties of fluoro-alkylated end-capped acrylamide oligomers

New fluoro-alkylated end-capped acryloylmorpholine (ACMO), N,N-dimethylacry lamide (DMAA) and N-isopropylacryamide (NIPAM) homo-oligomers were prepared by the reactions of the corresponding monomers with fluoro-alkanoyl peroxi des tinder very mild conditions. Furthermore, fluoro-alkylated end-capped a cryloylmorpholine co-oligomers were prepared by the co-oligomerizations wit h comonomers such as DMAA and NIPAM under similar conditions. It was found that these fluorinated oligomers, thus, obtained are soluble not only in wa ter but also in common organic solvents such as methanol, ethanol, tetrahyd rofuran, ethyl acetate, benzene, toluene, xylene, chloroform, tetrachlorome thane, dichloromethane and acetone, although fluoro-alkylated NIPAM homo-ol igomers are insoluble in water. Interestingly, these fluorinated acrylamide oligomers were able to reduce the surface tension of water and m-xylene qu ite effectively with a clear breakpoint resembling a critical micelle (or r everse micelle) concentration around 15 and 10 mN/m levels, respectively, w hich are almost the same levels as that achieved by the usual low molecular weight fluorinated surfactants. This suggests that these fluoro-alkylated end-capped acrylamide oligomers could form the intra- or inter-molecular ag gregates with the aggregations of end-capped fluoro-alkyl segments in aqueo us and m-xylene solutions. More interestingly, fluoro-alkylated end-capped acryloylmorpholine homo- and co-oligomers were found to have an extremely h igh calcium ion binding power, compared to traditional organic chelating ag ents and the corresponding non-fluorinated oligomers. These fluorinated oli gomers were also able to transfer alkali metal and heavy metal ions from aq ueous solutions into organic media. Therefore, these acrylamide oligomers a re suggested to have high potential for new fluorinated materials through t heir surfactant and metal ion binding properties. (C) 1999 Elsevier Science Ltd. All rights reserved.