Journal of Polymer Science Part A: Polymer Chemistry, Vol.51, No.6, 1387-1397, 2013
A non-phosgene process to homopolycarbonate and copolycarbonates of isosorbide using dimethyl carbonate: Synthesis, characterization, and properties
Poly(isosorbide carbonate) (PIC) was synthesized by melt polycondensation of dimethyl carbonate (DMC) and isosorbide using lithium acetylacetonate (LiAcac) as the catalyst. The reaction conditions were optimized to achieve PIC with relatively high number-average molecular weight (Mn) of 28,800 g/mol and isosorbide conversion of 95.2%. A series of poly(aliphatic diol-co-isosorbide carbonate)s (PAICs) were also synthesized by melt polycondensation of DMC with isosorbide and equimolar amounts of aliphatic diols (1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-cyclohexane dimethanol) in the presence of LiAcac and the TiO2/SiO2-based catalyst (TSP-44). PAICs with Mn values ranging from 18,700 to 34,400 g/mol and polydispersities between 1.64 and 1.69 were obtained. The 13C NMR analysis revealed the random microstructure of PAICs. The differential scanning calorimetry results demonstrated that all the PAICs were amorphous with a unique Tg ranging from 46 to 88 degrees C. The dynamic analysis results showed that the incorporation of linear or cyclohexane structure changed the dynamic mechanical properties of PIC drastically. (c) 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013
Keywords:aliphatic diols;copolycarbonate;dimethyl carbonate;isosorbide;polycarbonate;polycondensation;renewable resources