As a response to fossil fuels scarceness and a growing awareness of environmental threats, the quest for sustainable alternatives to oil and oil-based products is a must. Alternative resources to current raw materials are sought by the industry. Cellulosic biomass meets the challenge as potential raw material, forming the feedstock for second-generation biorefineries. For this to be attainable, a better understanding on the cellulose fundamental structural aspects, which is very limited at present, should be pursued. In this study, natural cellulose will be studied using the sugar cane bagasse after the removal of the hemicellulose and lignin by hydrolysis reactions in a dilute-acid medium and at several reaction rimes in the range 0-60 min. Special attention will be devoted to the analysis of low frequency modes that should probe differences in the structural packing of cellulose.