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

Polymeric Wet-Strength Agents in the Paper Industry: An Overview of Mechanisms and Current Challenges

Polymeric wet-strength agents are important additives used in the paper industry to improve the mechanical properties of paper products, especially when they come into contact with water. These agents play a crucial role in enhancing the durability, strength, and dimensional stability of paper products. The aim of this review is to provide an overview of the different types of wet-strength agents available and their mechanisms of action. We will also discuss the challenges associated with the use of wet-strength agents and the recent advances in the development of more sustainable and environmentally friendly agents. As the demand for more sustainable and durable paper products continues to grow, the use of wet-strength agents is expected to increase in the coming years.

Binary additives of polyamide epichlorohydrin-nanocellulose for effective valorization of used paper

This paper presents a binary reinforcement system of polyamide polyamine epichlorohydrin with nanocellulose (PAE-NC) for effectively modification of the reclaimed fibres for paper production, and based on the improvement of physical and mechanical properties of cellulosic fibres together with PAE-NC self-crosslinking networks, the strengthening mechanisms of recycled papers are examined. The PAE-NC binary system was applied directly to old corrugated container (OCC) and softwood bleached kraft pulp (SWBKP), and handsheets are prepared with varying amounts of PAE/NC/PAE-NC, namely 0.05, 0.1, 0.3, 0.5, 0.75, 1.0, 1.5, 2.0 wt% (dry pulp). The results showed that the studied additives improved the performance of recycled fibres, whether SWBKP or OCC pulp, and handsheets in solely or combined mechanisms except for the air permeability of the handsheets. The treatment of PAE-NC combination was significantly more effective than those of PAE or NC alone for both OCC and SWBKP, although the combined PAE-NC treatment results in better performance enhancement for OCC than SWBKP handsheets, and the NC alone is more effective than PAE for SWBKP recycled paper and conversely for OCC recycled paper. SEM observations further confirmed that the combined PAE-NC addition treatment imparted a relatively uniform surface structure to the handsheet.

Cellulose Nanofibers/Pectin/Pomegranate Extract Nanocomposite as Antibacterial and Antioxidant Films and Coating for Paper

Bio-based polymer composites find increasing research and industrial interest in different areas of our life. In this study, cellulose nanofibers (CNFs) isolated from sugar beet pulp and nanoemulsion prepared from sugar beet pectin and pomegranate extract (PGE) were used for making films and used as coating with antioxidant and antimicrobial activities for paper. For Pectin/PGE nanoemulsion preparation, different ratios of PGE were mixed with pectin using ultrasonic treatment; the antibacterial properties were evaluated to choose the formula with the adequate antibacterial activity. The antioxidant activity of the nanoemulsion with the highest antimicrobial activity was also evaluated. The nanoemulsion with the optimum antibacterial activity was mixed with different ratios of CNFs. Mechanical, greaseproof, antioxidant activity, and antibacterial properties of the CNFs/Pectin/PGE films were evaluated. Finally, the CNFs/Pectin/PGE formulation with the highest antibacterial activity was tested as a coating material for paper. Mechanical, greaseproof, and air porosity properties, as well as water vapor permeability and migration of the coated layer from paper sheets in different media were evaluated. The results showed promising applicability of the CNFs/Pectin/PGE as films and coating material with antibacterial and antioxidant activities, as well as good stability for packaging aqueous, fatty, and acidic food products.

Valorization and Development of Acorn Starch as Sustainable and High-Performance Papermaking Additive for Improving Bagasse Pulp and Paper Properties

Improving bagasse pulp and paper properties using forest-byproduct biomass, native Acorn starch (NAS), was compared with conventional wet-end additive cationic corn starch (CCS). The extracted acorn starch was characterized by SEM, XRD, and GPC. The results clearly showed irregular granular shape (6-12 μm) with rough surfaces, C_A-type XRD pattern, and 436.2 kDa molecular weights for NAS. The bagasse pulp retention and drainage as keys of operation performance and runnability were superior by NAS in comparison with CCS, while the lowest dosage of NAS (0.5%) showed superior results than the highest dosages of CCS (1% & 1.5%). The higher NAS adsorption onto the fiber surfaces compared to CCS could be concluded by higher water retention value (WRV) of the pulp together with higher density (up to 20%) and mechanical properties of the produced paper, e.g., tensile (up to 63%), burst (up to 37%) and tear (up to 11%) indices. NAS exploiting naturally as a papermaking additive would provide performance higher than commercial chemically-modified starch.