“…After sieving and drying, the solids were crushed with a ball mill (QM-ISP04, Nanjing University Instruments Co., Nanjing, China) to get MCC powder. To check the effects of different acid concentrations (v/v) and various reaction times on the degree of polymerization and crystallinity of the products, five acid concentrations (16,18,20,22, and 24%) with a reaction time of 3 h and five tested reaction times (2, 2.5, 3, 3.5, and 4 h) with an acid concentration of 20% were tested.…”