Effects of cellulose nanofibrils and starch compared with polyacrylamide on fundamental properties of pulp and paper.

Bio-based additives received significant attention in pulp and paper properties improvement. For this, the most cited biochemical Cellulose Nano Fibrils (CNFs) and Cationic Starch (CS) were experimentally compared with the most declared synthetic chemical, Cationic Polyacrylamide (CPAM). SEM images showed better paper surface filling by the utilization of the chemicals. The three studied polymers, in solely or combination mechanism, improved mainly bagasse pulp and paper properties compared to the blank sample, except for pulp drainage, which decreased by CNFs to lower volumes presumably due to its intrinsic characteristics. Cationic polymers (CP) compared to CP/CNFs approaches increased pulp retention and drainage but decreased paper density and strengths. The best pulp retention and drainage achieved by CS followed by CPAM, while paper air persistency, density, and strength properties evaluated highest by CP/CNFs followed by CNFs. Generally, CS revealed a more significant improvement in pulp and paper properties than CPAM either with or without CNFs.

Effects of cationic starch in the presence of cellulose nanofibrils on structural, optical and strength properties of paper from soda bagasse pulp.

The effects of widely available bio-based additives, cellulose nanofibrils (CNFs) (0.1, 0.5, 1, and 2 wt%, based on dry weight of pulp) in combination with high degree of substitution cationic starch (CS) (0.2, 0.4, and 0.6 wt%, based on dry weight of pulp) on the structural, optical and strength properties of handsheet paper made from soda bagasse pulp were studied. Obtained results indicated that both the type and loading level of the additives had meaningful effects (99% confidence level) on the evaluated properties. Scanning electron microscope (SEM) images showed the retention and reinforcing effects of the additives on the paper network. Tensile and burst strengths increased continuously with increasing levels of the bio-additives up to 33% and 23% (0.6 CS/2% CNFs), respectively. However, the cellulose nanofibrils improved retention and drainage of the pulp at the lower levels (0.5 CS/0.1 CNFs), presumably due to complex interaction between CNFs and CS. Moreover, for the handsheet papers made of semi-bleached soda bagasse pulp, higher addition of CNFs improved the brightness of paper.