A facile sodium alginate-based approach to improve the mechanical properties of recycled fibers

The application of recycled fibers is steadily increasing in various paper products recently. It is necessary to improve the mechanical properties of paper products made from these fibers. An eco-friendly polymeric additive, sodium alginate (SA), was prepared from waste seaweeds and developed as functional additives. The properties of SA were characterized by proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermal gravity analysis, gel permeation chromatography, and compared with the commercial SA. Coupled with polyamideamine-epichlorohydrin (PAE), the extracted SA was used to enhance the mechanical properties of paper from recycled fibers. The surface and cross-section morphology of the paper were measured by scanning electron microscopy and discussed. Compared with the single addition of PAE, the SA-PAE binary system significantly improved the mechanical properties of paper sheets.