Novel cellulose derivatives. V. Synthesis and thermal properties of esters with trifluoroethoxy acetic acid

✍ Scribed by James E. Sealey; Charles E. Frazier; Gamini Samaranayake; Wolfgang G. Glasser

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 197 KB
• Volume: 38
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(20000201)38:3<486::aid-polb14>3.0.co;2-s

✦ Synopsis

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 °C per DS-unit (from 160 to 41 °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°to 40 °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 (DS F ).