In this work, we studied the infl uence on the mechanical and physical properties of paper made of pulp from recycled cardboard and paper (printing/writing and newsprint) by adding different percentages of nanofi brillated cellulose. For each type of recycled pulp, we formed paper with incorporation of 0, 5 and 10 wt% nanofi brillated cellulose. The results showed that addition of nanofi brillated cellulose reduced the paper thickness and increased the density values. Papers with nanofi brillated cellulose presented resistance properties with values statistically superior to the treatments without addition. Addition of 10 % provided the best results, with improvement of tensile, burst and tear resistance of 97, 133 and 104 %, respectively, in comparison to normal papers. The paper produced with the recycled newspaper pulp had lower increase in mechanical properties from the nanofi brillated cellulose in relation to the papers with recycled pulp from cardboard and printing and writing paper. The considerable improvement in the mechanical properties is related to the increase of hydrogen bonds between the fi bers and nanofi bers, forming a dense network, resulting in greater surface area of nanofi brillated cellulose.
