The present invention provides conductivity control agents derived from the trans esterification of dialkyl phosphonium 5-sulfoisophthalate salts with poly(alkylene glycols). The conductivity control agents can be used with semi-conductive rolls, belts and other biasable members. The inclusion of the conductivity control agent in the polymeric or polyurethane elastomers extends the electrical life of the polymer biasable member in low humidity environments. Additionally, the resistivity of the elastomeric polymers or polyurethane on the biasable member is controlled to a desirable value by adjusting the conductivity control agent level in the polymer elastomers.