rbon ether radical, and a radical of a structure corresponding to that derivable from the reaction of a hydrocarbon isocyanate or alkoxy substituted or normally gaseous halogen substituted hydrocarbon isocyanate with a hydrocarbyl alcohol, hydrocarbyl mercaptan, hydrocarbyl phenol, hydrocarbyl thiophenol, hydrocarbyl carboxylic acid or hydrocarbyl amine, R is a phenylene or an alkylene radical, or