Cationic PolyAcrylamide/Cellulose Nanofibril Polyelectrolytes Effect on Suspension and Network Properties of Packaging Recycled fibers

Plant fibrous suspensions require electrostatically cationic polymers to provide proper and strong structures during papermaking. The charge bearing naturally and synthetically polymers (Polyelectrolytes), are considered as the most chemicals used in cellulosic products mills, due to improvement in the fibrous suspension and network properties. For this, cationic acrylamide polymer (CPAM) and anionic nano cellulose (ANC) were added individually and in combination forms into the fibrous suspension recycled from brown packaging papers. Compared to the blank sample without any the polymeric additive, the polymeric contained suspensions and networks revealed improvements in fibrous suspension properties; i.e., retention, freeness and the solid materials loss during the network formation; and in the fibrous dried network, include density, tensile and burst strengths. Individually application of each CPAM and ANC increased the suspension retention (productivity) as 8% and 2%, resp. Fibrous suspension freeness and loss materials content continuously increased and decreased up to 47%, respectively that could provide significant technologically and economically benefits. Paper density (+5%), tensile (+17%) and burst (+27%) properties improved drastically compared to the blank. But, tear strength of fibrous network decreased (-4%) which could be attributed to the network higher fines contents and retention, originated from the acrylamide polyelectrolyte flocculation effect. Individually application of ANC also enhanced suspension retention, network density, tensile and burst strengths and declined network tear strength with lesser suspension freeness and loss. Anionic nature, high specific surface area and huge hydrogen bonding potential of ANC are the main reasons of the obtained results. ANC post addition to CPAM contained suspension resulted in tear reduction, but higher suspension retention and freeness, together with higher density, tensile and burst strength of cellulosic network.