Strategies for the synthesis of fluorinated polyesters

In this work we synthetized three fluorinated polyesters from dimethyl tetrafluorosuccinate (DMTFS), dimethyl hexafluoroglutarate (DMHFG), and dimethyl octafluoroadipate (DMOFA) and ethylene glycol. The influence of parameters like monomer's size, temperature, vacuum, ultrasound and catalyst, on the polyesters synthesis was evaluated. The conversion rates were assessed considering 1H NMR data and the results disclose the role of ultrasound (US) as crucial to attain high reaction conversion rates (z20% of increase relatively to the reactions performed in absence of US). The effect of US was more relevant for the higher molecular weight monomers (DMHFG and DMOFA). The use of Candida antarctica lipase (immobilized CALB) marginally favors the synthesis reactions when fixing the other conditions. The size of the starting monomers influenced greatly the reaction conversion rates, as shorter monomers gave rise to high amount of product recovering. All the produced polyesters were isolated and fully characterized by NMR (1H and 19F), FTIR, TGA and MALDI-TOF.This study was supported by the Chinese government scholarship under the State Scholarship Fund (No. 201706790049), Training Fund for Excellent Doctoral Student in Jiangnan University, Key Projects of Governmental Cooperation in International Scientific and Technological Innovation (No. 2016 YFE0115700), Fundamental Research Funds for the Central Universities (No. JUSRP51622A). The study was also supported by the National Natural Science Foundation of China [No. 31470509], the 111 Project [No. B17021], Jiangsu Planned ProjectsforPostdoctoralResearchFunds[No.2018K018A]. This study was also supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 – Programa Operacional Regional do Norte. Jennifer Noro and Carla Silva also thanks to FCT for funding (SFRH/BD/121673/2016 and SFRH/IF/00186/2015).