Cellulose is an excellent raw material for a wide range of products, including cellulose derivatives and regenerated cellulose. Key factors when producing these products are high accessibility to solvents and reagents, and high reactivity. Cellulose with enhanced reactivity could drastically reduce chemical consumption during derivatization, which would be sustainable, and economically beneficial for several industries. However, it is well known that cellulose has a limited accessibility due to its compact structure of highly ordered regions caused by strong hydrogen bonding. This can, for example, lead to uneven substitution of hydroxyl groups and thus poor quality of the final product. Enhancing cellulose accessibility and reactivity is crucial for obtaining homogeneous products and improving process efficiency. Another challenge in cellulose processing is the presence of hemicelluloses in the pulp. For example, in viscose manufacturing, hemicelluloses can negatively impact viscose filterability, the xanthation process, and the mechanical properties of the final product. In previous studies, we have shown that the reactivity and accessibility of microcrystalline cellulose can be enhanced by swelling. This swelling is caused by dissolution in cold alkali, followed by precipitation with acetic acid. In this project, we want to evaluate if the swelling procedure has the same effect on softwood and hardwood kraft pulps. However, the high degree of polymerization of the commercial pulps makes dissolution and swelling difficult. Controlled acidic hydrolysis has therefore been used to lower the degree of polymerization of the pulps. The aim is to investigate how reduced viscosity affects swelling, as indicated by water retention value, and chemical reactivity. We will also monitor the hemicellulose content during the process to evaluate whether the swelling process decreases the hemicellulose content in the pulps.