Summary – Complexes with nanofibrillated cellulose (NFC) and cationic polyelectrolyte (Poly-DADMAC), at seven levels of charge density ratio (q+/q-), were evaluated to improve packaging paper properties. Technical aspects and operational variables, such as retention and drainage of fiber suspension, were analyzed. A reference test without NFC and polyelectrolyte complexes served as a benchmark. Unbleached pine cellulose pulp with an average kappa number of 95, mechanically pretreated to achieve a low refining level (19 °SR), was used. For complex preparation, cationic polyelectrolyte (Poly-DADMAC) and nanofibrillated cellulose derived from bleached fiber were combined. The study considered the charge densities of unbleached long fiber pulp, NFC, and the polyelectrolyte to optimize retention and paper quality through electrostatic interactions.
The combination of NFC and cationic polyelectrolyte complexes, at varying charge ratios (q+/q-), resulted in suspensions with distinct equilibrium charge densities compared to isolated components. This interaction facilitated structures with tailored charge densities, providing a positive residual for fiber surface adsorption. Optimal tensile strength, air resistance, and water vapor permeability were achieved with near-neutral charge density ratios, q+/q- = 100/75 and 100/100. For retention and drainage, the complexes improved retention but reduced drainage at a 3% NFC level.
Keywords: Nanotechnology; Nanofibrillated cellulose and cationic polyelectrolyte complexes; Packaging papers; Retention and drainage; Physical-mechanical strength.
REFERENCES: O PAPEL vol. 86, N.o 1, pp. 60 – 65 – JAN 2025
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Authors: Isabela Cabral Ferreira1
, Millena Braga de Souza1
, Renê Chagas da Silva2
, Taila Veloso de Oliveira3
, Ana Márcia Macedo Ladeira
Carvalho4
, José Mauro de Almeida4
, Deusanilde de Jesus Silva1
1 Industrial Processes and Materials Laboratory, Chemistry Department, Federal University of Viçosa, Viçosa (MG), Brazil.
2 Scanning Electron Microscopy Laboratory, Physics Department, Federal University of Viçosa, Viçosa (MG), Brazil.
3 Packaging Laboratory, Food Engineering Department, Federal University of Viçosa, Viçosa (MG), Brazil.
4 Pulp and Paper Laboratory, Forest Engineering Department, Federal University of Viçosa, Viçosa (MG), Brazil
Corresponding author: Isabela Cabral Ferreira. Viçosa, MG, Brazil – 36572-160.
Phone: (+55-31) 98259-0845. E-mail: [email protected].
