Synthesis, Characterization, and Evaluation of Chitosan-Complexed Starch Nanoparticles on the Physical Properties of Recycled Paper Furnish

The objectives of the current research were to synthesize and characterize chitosan-complexed starch nanoparticles and examine their effect on the physical performance of recycled pulp, specifically old corrugated containerboard (OCC). This new approach provides a uniquely renewable and useful approach to enhance mechanical properties of pulp while maintaining environmental compatibility, industrial compatibility, and paper qualities. The starch nanoparticles used for the research were prepared from cooked cornstarch gel with ethanol and reacted with diethylenetriamine pentaacetic acid (DTPA) in the presence of sodium hypophosphite. Thereupon, the DTPA-modified starch nanoparticles (SNs) were complexed with chitosan as part of a general chemical strategy to improve their incorporation into an OCC matrix and increase interfiber bonding. Spectral characterization of the SNs was done using TGA, DSC, FT-IR, and SEM to analyze their composition and structure. Approximately 2% chitosan-complexed starch nanoparticle derivatives by mass (SNX/C) of OCC-based slurry were thoroughly mixed before manufacturing a two-dimensional sheet for physical testing. The tensile and burst strength of the modified OCC pulp sheet increased 50 and 49%, respectively, albeit having a decreased tear strength compared to the control sample. However, when the OCC pulp sheet was coated with a 1% SNX/C by mass solution, the tensile and burst strength increased 120 and 70%, respectively, while also providing significantly increased gloss, decreased roughness, and tear strength. Because the mechanical properties are the most critical property facing the recyclability of OCCs, the tremendous gains afforded by the starch nanoparticle DTPA chitosan proposed give the system enormous potential applicability as a viable dry strength agent for paper substrates.