Design of sustainable bioplastics can be achieved by preparing composites from renewable materials like
microcrystalline cellulose (MCC) fibre and biopolymer such as polylactic acid (PLA). The key driving
factor that affects their performance is the quality of dispersion of MCC in the PLA matrix. In this study,
surface modification, one way to facilitate improved dispersion, is carried out by acetyl chloride. PLA
composites were prepared with the acetylated MCC applying solvent casting technique. Confirmation of
acetylated group is accompanied by FTIR and NMR study. Change in crystalline property and thermal
behaviour is observed by XRD study. Improvement in storage modulus (G′) is reflected in shear
rheological tests, reaching an optimal value at 2.5 wt%. This improvement is primarily attributed to a
more homogeneous dispersion of MCC in the matrix. Rheological percolation threshold is calculated to
quantify the level of dispersion. This study is aimed to quantify the level of dispersion of acetylated MCC,
as compared to pure MCC by shear rheology