Kinetics and mechanism of cationic oligomerization of styrene using poly(styrenesulphonic acid) resin as catalyst

The cationic oligomerization of styrene in benzene using poly(styrenesulphonic acid) resin as catalyst, was carried out under nitrogen. A kinetic model involving initiation, propagation, chain transfer to monomer and spontaneous termination steps, is proposed to fit the experimental kinetic data. It is found that (1) the propagation constant decreases with increasing chain length and remains constant as $\text{n ≧ 5}$; (2) the constant for chain transfer to monomer is also chain length dependent and reaches a maximum at n = 4.