Effects of alkyl and phenyl-substituted 1,3-propanediols on the synthesis and properties of polyesters with 2,5-furandicarboxylic acid

Polyesters with furan groups have generated interest due to the renewability of furan containing monomers. Eleven diols were evaluated in polymerizations with the dimethyl ester of 2,5-furandicarboxylic acid, of which 8 diols were novel. The diols included 1,3-propanediol, 2-alkyl-1,3-propanediols and 2,2-dialkyl-1,3-propanediols, with alkyl groups ranging from methyl up to butyl, as well as their phenyl analogues. Molecular weight properties of the polyesters were determined by size exclusion chromatography. NMR spectra of all polyesters and peak assignments are discussed. Glass transition temperatures and where applicable, melting temperatures, were determined by DSC and DMA. Thermal degradation was determined by TGA. By selecting a specifically substituted diol it is possible to obtain the glass transition temperatures of these polyesters over a wide range (40–93 °C, based on tan δ). The effect of the number of carbons in the alkyl groups and the underlying effects on the glass transition temperature are discussed. [Display omitted] •1,3-Propanediols with 2-alkyl or 2,2-dialkyl groups (0–4 carbons in alkyl group) were polymerized to polyfuranoates.•Altogether 8 novel diols were applied, including 2-phenyl and 2,2-diphenyl-substituted 1,3-propanediol.•The mostly renewable polyesters were fully characterized by 1H and 13C NMR spectroscopy, GPC, DSC, TGA and DMA.•With the monoalkyl-substituted diols, Tg decreased monotonously with increasing number of carbons in the alkyl group.•With the dialkyl-substituted diols, Tg values with alkyl groups bearing an odd number of carbons are significantly larger.