A comparative study of nanofibrillated cellulose and microcrystalline cellulose as reinforcements in all-cellulose composites

The reinforcing abilities of nanofibrillated cellulose (NFC) and microcrystalline cellulose (MCC) in composites were investigated and compared. All-cellulose composites were prepared using the dissolved MCC as the matrix, and NFC and MCC were introduced as the reinforcing phase. With the addition of MCC, tensile strength of the composites decreased; on the other hand, the higher tensile strength of the composites with NFC was found with increasing a NFC content. Strong interfacial interaction between the matrix and reinforcing phase could be obtained at a low content of the reinforcement was observed. At a higher content of the reinforcement the fiber pull-out was found from the fracture surface of the composites after tensile deformation. The reinforcing abilities of NFC and MCC were also confirmed by the comparison between values of the Young's moduli of the composites obtained from the experiments and calculations using the rule of mixtures equation. From these results it could be summarized that NFC had the higher reinforcing ability than MCC.