Nucleation effects of -cyclodextrin inclusion complexes on the crystallization behavior of biodegradable poly(1,4-butylene adipate)Electronic supplementary information (ESI) available. See DOI: 10.1039/c3ce26844f

This study examined the polymorphic crystallization behavior of poly(1,4-butylene adipate) (PBA) with the addition of nucleation agents such as the -cyclodextrin (-CD) inclusion complex (IC) of PBA (PBAIC) and the IC of poly(-caprolactone) (PCLIC). The formation of PBAIC and PCLIC was characterized by 1 H NMR, Fourier-transform infrared (FT-IR) spectroscopy and wide-angle X-ray diffraction (WAXD). The differential scanning calorimetry (DSC) and WAXD results suggest that some of the PBA segments remained outside the -CD cavities even after the formation of ICs with -CD. WAXD investigation also confirmed that the ICs had a channel structure. The DSC and polarized optical microscopy (POM) results showed the ICs to exhibit nucleation effects on the crystallization and polymorphic behavior of the PBA. The cooling rate played a significant role in the polymorphic crystallization behavior of the pure PBA. Thus, when the cooling rate was decreased, the crystal structures changed from to -form and vice versa . The blending of a nucleating agent with the PBA led to higher crystallization temperatures, thus favoring the nucleation of the -form crystal of PBA rather than pure PBA. The nucleating activity of the PCLIC during the crystallization of the PBA was higher than that of PBAIC. This study examined the polymorphic crystallization behavior of PBA with the addition of IC based nucleation agents such as PBAIC and PCLIC. PBAIC has been demonstrated to be lower nucleating activity than PCLC, possibly due to the uncovered PBA segments.