Préparation de copolymères greffés par voie cationique-1: Etude du greffage cationique de l'indene sur le caoutchouc butyl chlore

Cationic grafting of indene onto chlorinated butyl rubber (CBC), initiated with diethylaluminium monochloride in a mixture of methylene dichloride and methylcyclohexane, has been carried out at ?50°. Grafting efficiencies near 100% and complete conversion of indene were obtained. The polymerization rate is proportional to indene concentration and to $\text{(}\text{initiator concentration}\text{)}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$, as in reactions carried out in the presence alkyl halide cocatalysts. No simple dependence on cocatalytic chlorine could be found. Influence of the concentration of reagents on the nature of the reaction products, especially of the ratios

$\text{(CBC)}\text{(indene)}\text{(AlEt}{}_2\text{Cl)}\text{and}\text{(AlEt}{}_2\text{Cl)}$

has been measured. Since transfer reactions occur during polymerization, the high grafting efficiencies are attributed to grafting of transfered polyindene chains.