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Previously syntheses of poly(isosorbide 1,4-cyclohexanedicarboxylate) (PICD) have overcome synthetic problems associated with the low-reactivity of isosorbide, using acetic anhydride to achieve in situ acetylation. However, this amorphous polymer exhibits unusual behavior when submerged in water at 100 °C. Severe deformation occurs, with cylindrical pellets changing into a disc-like morphology, similar to solvent-induced crystallization. The influence of water on the thermal behavior of PICD was analyzed, resulting in a mechanism analogous to solvent-induced crystallization, where the solvent functions as a plasticizer. Furthermore, the effects of acetic anhydride and open-ring isosorbide on structural deformation were investigated, revealing the occurrence of ester hydrolysis. Finally, solid state CP-MAS 13C-NMR was used to elicit the rearrangement or packing of carbons within the PICD structure.

This research fabricated novel nanofibers with a terpolyester of isosorbide, ethylene glycol, 1,4-cyclohexane dimethanol, and terephthalic acid (PEICT) using electrospinning and characterized their properties. The nanofibers have higher glass transition temperature (Tg) than other polyester-type polymers, and a smaller diameter nanofiber has higher Tg than a larger diameter nanofiber. This is due to the orientation of polymer chains inside nanofibers, which was verified by DSC and polarized ATR-FTIR. The morphology and diameter of the nanofibers affected by concentration of PEICT solution were studied by SEM. It demonstrated smooth and well-formed nanofibers, and showed an increase of the diameter with increasing concentration. In addition, the tensile property, which was confirmed by UTM, was enhanced with increasing diameter because molecular orientation existed in finer nanofibers. They show a better tensile property than general biobased nanofibers such as silk, chitosan, and gelatin. Finally, fabrication of PEICT nanofibers was optimized and characterized. They can be utilized in various industrial applications such as tissue engineering, wound dressings, and health care devices.

A series of poly(1,4-cyclohexanedimethyl-trimethylene glycol terephthalate), (PCTG), co-polyesters were synthesized using 1,3-propanediol (PDO) and 1,4-cyclohexanedimethanol (CHDM) via melt polymerization. The characteristic of having a high thermal shrinkage ratio at low processing temperature conditions and a suitable molecular weight for film manufacture, with Mn ranging from 20 000 to 25 000 g mol−1 and a polydispersity of 1.8–2.0, suggests the use of the biobased monomer, PDO, in the film industry. The composition of the PCTG samples was confirmed using 1H-NMR spectroscopy. 2D NMR analyses (correlation spectroscopy (COSY) and heteronuclear single quantum correlation spectroscopy (HSQC)) were performed to analyze detailed structural information for PCTG. Sequence distribution was used to reveal the effect of PDO dyads in the polyester chain and identify the structural effect. In the case of the transesterification time, under fixed esterification conditions, it decreased as the CHDM content increased due to the high reactivity of CHDM which has a higher boiling point. A thermal shrinkage ratio test was done with the temperature ranging from 70 °C to 100 °C. As the PDO content increased, the low temperature conditions showed a relatively higher thermal shrinkage ratio owing to the structural characteristics of CHDM and PDO. This result could induce advantageous energy savings in heat shrink processes at low temperatures.