Cyclic and non cyclic aliphatic-aromatic polyesters derived from biomass: Study of structures by MALDI-ToF and NMR

New polyesters were prepared by polycondensation in solution of 1,4:3,6 dianhydrohexitols with various aliphatic aromatic acid dichlorides which differ by their chain length (m = 6,8,10). They are obtained with yields in the range of between 89% and 95%. In order to obtain these polymers within optimum conditions, a systematic study was conducted on the effect of the parameters involved in the reaction, such as the alkyl chain length of acid dichlorides and the endo or exo positions of hydroxyl function of diols. The resulting polyesters were characterized by different analytical techniques such as NMR ((1)H and (13)C), FT-IR spectrometry, SEC measurements and MALDI-ToF mass spectrometry. Under optimized conditions a high molar fraction of cyclic polyesters was formed. The differential scanning calorimetry (DSC) measurements revealed an amorphous character with glass transition temperatures in the range of 27-45 degrees C. The polymers are obtained with inherent viscosities in the range of 0.11-0.25 dL/g with a polydispersity index between 1.75 and 1.99. (C) 2011 Elsevier Ltd. All rights reserved.