Innovative system based on natural polyelectrolyte complex and cellulose micro/nanofibers to improve drainability and properties of recycled paper

Abstract In this work, the efficiency of a polyelectrolyte complex (PEC) to retain different cellulose micro/nanofibers (CMNFs) during paper formation and improve physical properties recycled unbleached fiber was analyzed. CMNFs were obtained from commercial bleached eucalyptus pulp (BEP) using PFI refiner followed by chemical treatment with oxalic acid at two concentrations. Finally, fibrillated high-pressure homogenizer three intensities. The PEC formed addition xylan (Xyl) solution on chitosan (CH) Xyl/CH mass ratio 80/20. required dosages neutralize charges nanocellulose fractions determined ζ-potential measurements, CMNF retentions fibers evaluated in Britt Dynamic Drainage Jar. results showed that maximum retention when neutral PEC-CMNF system added pulp. Besides, significant decrease °SR observed systems untreated pulp, limiting negative effects drainability. incorporation handsheets increased tensile index (up 28%), Mullen 40%) internal bonding 255%). compressive strength handsheets, namely SCT CMT, up 30 70%, respectively. These simultaneous improvement drainability mechanical makes proposed promising for production packaging paper.