Post-grafting of polymer with controlled molecular weight onto silica surface by termination of living polymer cation with terminal amino groups of dendrimer-grafted ultrafine silica

摘要

To modify the surface of ultrafine silica, the grafting reaction of living polymer cation with dendrimer-grafted silica having terminal amino groups was investigated. The polyamidoamine dendrimer-grafted silica having terminal amino groups was readily reacted with living poly(isobutyl vinyl ether) (polyIBVE), which was synthesized by cationic living polymerization with a HCl/ZnCl_2 initiating system, and polyIBVE with controlled molecular weight and narrow molecular weight distribution was post-grafted to the dendrimer-grafted silica surface. By the termination of living poly(2-methyl-2-oxazoline) (polyMeOZO), which was synthesized by cationic ring-opening polymerization with methyl p-toluenesulfonate initiator, with terminal amino groups of polyamidoamine dendrimer-grafted silica, polyMeOZO was also post-grafted to the surface of polyamidoamine dendrimer-grafted silica; the percentage of overall grafting of polyMeOZO was determined to be 361.6% based on silica.