Polymers are formed by the condensation of bis(hydroxycarbyl)-aminophenolic compounds with aldehydes. The condensation polymers include one or more repeat units having bis(hydroxycarbyl)amino functionality. The polymers are useful as antifoulants, antipolymerants, rheology modifiers, dehazers, polymerization retardants, surfactants, or a combination of these in one or more industrial process streams.