Macromolecular synthesis using mesoporous zeolites

Mesoporous zeolites such as MCM-41 were found to serve as nano-flasks for f ree radical polymerization of methyl methacrylate (MMA), where the formatio n of long-lived propagating radicals was observed. Al-MCM-41 with a Lewis-a cidic aluminosilicate framework catalyzed living ring-opening polymerizatio n of cyclic esters such as delta-valerolactone and epsilon-caprolactone, to give narrow molecular-weight-distribution polyesters. With Ti-MCM-41, a ti tanate-containing mesoporous silica, ring-opening polymerization of delta-v alerolactone also took place to give a high molecular-weight polyester. On the other hand, with Ti-MCM-41 I in the presence of methylaluminoxane (MAO) , ethylene was polymerized to give a high molecular-weight, linear polyethy lene.