<p>Maize starch is hydrolysed using H₂SO₄ and the effects of varying acid concentrations (1M, 2M, 3M and 3.16M) on the morphological, thermal and structural properties of hydrolysed starch are studied. With the increasing acid concentration used for hydrolysis, crystallinity, anisotropy in the shape and non-uniformity in the size of hydrolysed starch particles increases. However, thermal stability, amylose content, and average molecular weight decreases. Acid hydrolysis leads to the formation of hydroxyl group in the starch molecule. Hydrolysis increases the size range of starch particles, by creating small particles due to disintegration and larger particles due to agglomeration. Starch hydrolysed using 2M acid concentration shows quite different behaviour, where thermal stability remains same as native starch, crystallinity decreases, and highest number of hydroxyl groups are formed as compared to other acid concentrations. From this study it becomes evident that 2M acid concentration is best for hydrolysis of starch, as it leads to maximum functionalization. This study focuses on preparing functionalized starch having maximum functionality which is suitable as filler in making bio-composites.</p>