Self‐polyaddition of triethylsilyl perfluoroisopropenyl ether

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)2C6H5] (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 × 104 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.