H. Sawada et T. Kawase, Synthesis of fluoroalkyl end-capped oligomers with fluoroalkanoyl peroxides-architecture of self-assembled aggregates of these oligomers, KOBUNSH RON, 58(4), 2001, pp. 147-160
Fluoroalkanoyl peroxides were demonstrated to exhibit quite different decom
position behavior from the corresponding nonfluorinated alkanoyl peroxides,
owing to the strong electron-withdrawing properties of the fluoroalkyl gro
ups. In fact, fluoroalkanoyl peroxides decompose easily to afford fluoroalk
yl radicals with a concerted homolytic dissociation with a three-bond fissi
on. This unique behavior was applied to the direct introduction of the fluo
roalkyl group into the end-sites of oligomeric molecules via a radical proc
ess. These fluoroalkyl end-capped oligomers thus obtained possess good solu
bility not only in water but also in common organic solvents. Additionally,
these fluoroalkyl end-capped oligomers were able to reduce the surface ten
sion of watts and organic solvents veri effectively with a clear break poin
t resembling a CMC (critical micelle concentration). This finding and stati
c light scattering measurements showed that these fluoroalkyl end-capped ol
igomer can form the self-assembled molecular aggregates with the aggregatio
ns of end-capped fluoroalkyl segments in these solvents. In particular inte
rest, fluoroalkyl end-capped oligomers containing betaine segments or hydro
xyl segments could cause gelation derived from the synergistical interactio
n of the aggregations of end-capped fluoroalkyl segments and the ionic inte
ractions of betaine segments (or the intermolecular hydrogen-bonding intera
ctions between hydroxyl segments) in water and polar organic solvents.