Polymeric plasticizers are used in PVC applications to provide flexibility, softness and lower modulus values and to maintain these characteristics after exposure of the PVC compound to severe use conditions or harsh environments. Polymerics are more permanent (stable) under extended, high heat conditions and less likely to volatilize out of the PVC compound than are monomeric plasticizers. Polymeric plasticizers are resistant to extraction (leeching) by solvents, oils and fluids, and they resist migration to other polymer compounds in contact with the PVC material. In short, polymeric plasticizers provide greater permanence than monomerics in PVC applications.