Synthesis and evaluation of dialkyl furan‐2,5‐dicarboxylates as plasticizers for PVC

Di(2‐ethylhexyl), di(2‐octyl), dihexyl, and dibutyl furan‐2,5‐dicarboxylate were synthesized from furfural and characterized for their plasticizing abilities toward PVC by dynamic mechanical thermal analysis (DMTA) with di(2‐ethylhexyl) phthalate (DOP) as the standard of reference. DMTA gave values for the depression of the glass transition temperature (Tg) per mass fraction of plasticizer, and it also yielded a set of parameters, relative to those for DOP, which describe the compatibility of the furan diesters with PVC. The efficiency in lowering Tg as exhibited by di(2‐ethylhexyl) furan‐2,5‐dicarboxylate is similar to that of its benzenoid analog, DOP, and was determined at 2.41 and 2.45°C per mass % plasticizer, respectively. All four furan diesters were found to be more compatible toward PVC than toward DOP, with dibutyl furan‐2,5‐dicarboxylate the most highly compatible.