The synthesis of functionalized fluorocooligomers based on chlorotrifluoroethylene (CTFE) and allyl glycidyl ether (AGE) under radical copolymerization is presented. The compositions of comonomers in the cooligomers were determined by three different analyses viz: from H-1 and F-19 NMR spectroscopy by using 1,3-bis(trifluoromethyl) benzene as the external standard, epoxy equivalent weight value, and elemental analyses. The compositions determined by three methods were matching reasonably well and showed that the resulting poly(CTFE-co-AGE) cooligomers exhibit a tendency for alternation. The distribution of the monomers in the cooligomers was proposed based on the assessment of the reactivity ratios, r(1), of both comonomers. These values were determined from the kinetics of radical copolymerization of CTFE with AGE from Fineman-Ross, Kelen-Tudos, and extended Kelen-Tudos methods which led to the assessment of the average reactivity ratios as: r(CTFE) = 0.20 +/- 0.03 and r(AGE) = 0.15 +/-0.08 at 74 degrees C. The lower M-n values substantiated the formation of cooligomers rather than copolymers. The formation of cooligomers was attributed to the chain transfer to AGE (by hydrogen abstraction from AGE) from the allylic transfer. The poly(CTFE-co-AGE) cooligomers were soluble in most of the common organic polar solvents. An optimization of cooligomer yields was investigated by using ethyl vinyl ether as a third comonomer and from different initiators. The thermal stabilities of the cooligomers, obtained by thermal gravimetric analysis, showed a 5% weight loss at temperatures over 225 degrees C under air. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3587-3595, 2010