Abstract: The kinetics of the cyclization of styrene-isoprene rubber has been investigated by IRspectrum. Some kinetic parameters of this cyclization are determined.Reaction order n=1,apparent activation energy E_a=53.2 k_J·mol^-1,preexponential factor A=2.24×10⁶min^-1.The structure of cyclized styrene-isoprene rubber was analysed by ¹H NMR experiments.The possible mechanisms of this cyclization have been suggested and discussed.

Key words: styrene-isoprene, cyclization, kinetics mechanism IR, ¹H NMR To whom correspondence should be addressed.