Polymerization of Vinyl Ether by Use of Yttrium Silicate Gel as Solid Acid

Abstract

The gel of yttrium silicate was utilized as a solid catalyst for the polymerization of vinyl ethers. Several silicate gels showing the different element ratios of silicon and yttrium were prepared by the co-gelation of sodium metasilicate and yttrium(III) chloride from an acidic aqueous solution through neutralization by an aqueous ammonia. The polymerizations of ethyl vinyl ether and n-butyl vinyl ether proceeded readily in the presence of a catalytic amount of the silicate gel to give the corresponding polymers. When ethyl vinyl ether was used in benzene solution for the polymerization, the concentration of the monomer was not an essential factor which affected on the yield of the corresponding polymer. This demonstrated that the silicate gel provided an effective reaction environment for the polymerization with the catalytic sites.