Esters of cellulose with trifluoroethoxy acetic acid (TFAA) were prepared in homogeneous phase using a mixed anhydride with p-toluenesulfonic acid. Esters with low degree of substitution (DS), and with DS rising from 0 to 3, had hydrophobic character that prevented the usual association with moisture, which is otherwise typical of cellulose esters with low DS. Cellulose trifluoroethoxy acetate (CT) had T-g's declining by about 40 degrees C per DS-unit (from 160 to 41 degrees C) as DS rose from 1 to 3. Mixed esters, cellulose derivatives with acetate and trifluoroethoxy acetate substituents (CAT), exhibited glass-to-rubber and melting transitions by DSC. A linear relationship between both T(g)and T-m with respect to DS was recorded with the T-g and T-m separated by 30 degrees to 40 degrees C. This is consistent with cellulose esters described elsewhere. surprisingly, the T-g's of CT and CAT were found to be identical when the DS was equivalent to the DS of the fluoro substituents (DSF ).