Cellulose acetate CA was produced from paper wastes by acetylation reactions with glacial acetic acid, concentrated H2SO4, and acetic anhydride. The degree of substitution (DS) values can be controlled by the acetylation time leading to biodegradable cellulose derivatives, which a necessary characteristic is considering environmental and economic aspects. Different acetylation times were analyzed in this work, to study the variation in the quality and degree of substitution (DS) of the cellulose acetate produced. Characterization by using H-NMR, 13C-NMR spectroscopy, X-Ray and SEM revealed a high degree of substitution (DS). The purity of CA is shown by solubility test.