Characterization of the prepolymer and gel of biocompatible poly(xylitol sebacate) in comparison with poly(glycerol sebacate) using a combination of mass spectrometry and nuclear magnetic resonance

Atmospheric pressure chemical ionization (negative ion) and electrospray ionization (positive and negative ion) mass spectrometry and nuclear magnetic resonance (H-1 NMR and C-13 NMR) were used to characterize the prepolymer (i.e. uncrosslinked) poly(xylitol sebacate) (PXS), prepared by condensation of xylitol [X] and sebacic acid [S], and this was compared with poly(glycerol sebacate) (PGS), prepared by condensation of glycerol [G] and [S]. The PXS prepolymer, prepared at 118 degrees C/24 h, gave predominantly 1-acyl-[XS] and 1,5-diacyl-[SXS] species and smaller amounts of 2-acyl substitutions. At 130 degrees C/24 h an increase of the amount of the 1-acyl and 1,5-diacyl substitutions in the [(SX)(n)], [S(XS)(n)] and [(XS)(n)X] series was identified, as was found for the analogous PGS prepolymer ([(SG)(n)], [S(GS)(n)] and [(GS)(n)G] series). Novel tetrahydrofuranyl species were found in the PXS prepolymer. Further polymerization of the PXS prepolymer gave a gel which when analysed using C-13 NMR was shown to mainly contain 1-acyl and 1,5-diacyl substitutions. (c) 2014 Society of Chemical Industry