Abstract: There are described vinyl ether terminated ester oligomers which cure or polymerize particularly rapidly, especially by cationic polymerization which is radiation induced in the presence of an onium salt. The oligomeric units arise from the reaction of a polycarboxylic acid having at least three carboxylic acid groups with a diol, although esters with triols and higher polyhydric diols also are useful, especially where an extensively cross-linked product is desired. The carboxyl-terminated oligomeric esters are esterfied with vinyl ether terminated alcohols which can be thought of as the adducts of alkynes and diols.