*2.5. Characterization*

The TEM images of PBSA composites were performed using JEM-2010 (JEOL, Tokyo, Japan). The scanning electron microscopy (SEM) images of PBSA composites were performed using JSM-6700F (JEOL, Tokyo, Japan). The contact angle was carried out on FTA200 (First Ten Angstroms, Portsmouth, VA, USA). FTIR experiments of Zn-Ti LDH, SA, and m-LDH were carried out on a spectrometer (Spectrum One, Perkin-Elmer, Waltham, MA, USA) in the range from 450 to 4000 cm−<sup>1</sup> . The PBSA and its composites were performed in attenuated total reflection (ATR) mode. The UV absorption spectrum was acquired by a U-3900 UV–vis spectrophotometer (Hitachi, Tokyo, Japan) in the range of wavelength from 250 to 400 nm. X-ray diffractometer (Bruker D8, Karlsruhe, Germany) equipped with a Ni-filtered Cu Kα radiation was used for the experiments of wide-angle X-ray diffraction (WAXD). The measurements of WAXD were carried out in the range of 2θ = 1–40◦ at scanning rate of 1◦/min. The thermal degradation of specimens was operated using thermal gravimetric analyzer (TGA 2950, TA Instruments, New Castle, DE, USA). The experiment was carried out from room temperature to 600 ◦C under atmospheric environment at a heating rate of 10 ◦C/min. The crystallization behavior was carried out by a Pyris Diamond DSC (Perkin-Elmer, Waltham, MA, USA) and all experiments were performed under nitrogen environment. All specimens were heated to the designed temperatures (Tds), which were about 40 ◦C higher than the melting temperatures of neat PBSA, at a rate of 10 ◦C/min and held for 5 min. Then, they were cooled to −30 ◦C at a rate of 10 ◦C/min, which was called 1st cooling. Finally the samples were heated to Tds at a rate of 10 ◦C/min, which was called 2nd heating. The crystallinity degree (Xc) of neat PBSA and the composites was obtained according to enthalpy of the melting peak (∆H<sup>f</sup> ) of 2nd heating. The storage modulus (E0 ) was evaluated by DMA8000 (Perkin-Elmer, MA, USA) from −80 to 40 ◦C at 2 ◦C/min heating rate and 1 Hz constant frequency. Sample size is 20 mm × 10 mm × 0.5 mm (L × W × T). The experiment was performed in atmospheric environment. Molecular weights of the samples were determined by GPC (LC-4000, JASCO, Tokyo, Japan) with a refractive index detector (RI-4030, JASCO, Tokyo, Japan) calibrated with standard polystyrene. Dichloromethane was used as the mobile phase with a 1 mL/min flow rate.
