The results on radical self-polyaddition reactivity of two trialkylsilyl perfluoroisopropenyl ethers, triethysilyl perfluoroisopropenyl ether [CF2=C(CF3)OSi(C2H5)(3)] (FTEE) and dimethylphenylsilyl perfluoroisopropenyl ether [CF2=C(CF3)OSi(CH3)(2)C6H5] (DMPE), and two perfluoroisopropenyl carboxylates, 2-butyroxypentafluoropropene [CF2=C(CF3)OCOC3H7] (BuFPP) and 2-(methoxyacetoxy)pentafluoropropene [CF2= C(CF3)OCOCH2OCH3] (MFPP), are described. Radical self-polyaddition of FTEE afforded a polymer as high as 1.87 x 10(4) in molecular weight in the presence of radical generators such as benzoyl peroxide and di-tert-butyl peroxide. DMPE gave only addition products with initiating radicals. BuFPP and MFPP scarcely yielded even addition products with radical. The mechanism that the self-polyaddition of FTEE was initiated by the addition of radical onto the perfluoroisopropenyl group followed by a 1,5-shift to afford a methyl radical that attacked the perfluoroisopropenyl group of another FTEE molecule is proposed. (C) 2003 Wiley Periodicals, Inc.