Phthalates pose adverse health effects due to their propensity to leach and the most common, di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DOP), are petroleum-based. Conversely, di-esters, succinates are biobased (produced from fermentation of biomass), biodegradable, and therefore potential sustainable replacements for phthalates. A series of succinates, di-octyl succinate (DOS), di-hexyl succinate (DHS), di-butyl succinate (DBS), and di-ethyl succinate (DES), were mixed with poly(vinyl chloride) (PVC). The interaction of the plasticizer ester carbonyl with PVC shows an average -5 cm-1 shift of the carbonyl absorbance peak energy. The glass transition temperatures (Tg), were monitored by differential scanning calorimetry and dynamic mechanical analyses. The Tgs of DOS and DHS plasticized PVC were significantly lower than DOP plasticized PVC at a lower percent mass. On the other hand, PVC plasticized with either DBS or DES exhibited a similar trend in lowering the Tg as that of DOP plasticized PVC.