2.9. Solubility test
0.1 g of CS-g-PBT was dispersed in 1 mL of distilled water or 1% (w/v) acetic acid aqueous solution and stirred at 60◦C for 6 h.High temperature has also been endowed to do the water solubility tests by other researchers to improve the dissolution rate and save time [20–22]. The samples were then centrifuged at 10,000 rpm for 10 min. The transparent solution was carefully pipetted out without disturbing the precipitated sample concentrated at the