Starch Derivatives that Contribute Significantly to the Bonding and Antibacterial Character of Recycled Fibers

The objective of the current research was to fabricate and explore the ability of a renewable resource-based paper strength agent to enhance fiber-fiber bonding and introduce antibacterial properties to recycled fiber paper sheets. The agent corn starch, was modified with diethylenetriamine pentaacetic acid (DTPA), complexed with chitosan, and added to recycled furnishes to provide a plethora of hydrogen bonding sites predicated by acid groups, hydroxyls, and amines. The goal was two-fold: (1) to not only increase interfiber bonding, but (2) afford antibacterial character. The modified corn starch was characterized in previous work by thermal gravimetric analysis, differential scanning calorimeter, and Fourier transform infrared spectroscopy. The recycled pulp slurry was mixed with a ∼1.5% modified starch/chitosan agent before manufacturing a two-dimensional paper substrate that was subjected to mechanical testing. The burst, STFI compressive strength, tensile, and interfiber bonding strength increased 48.8, 49.5, 49.9, and 176%, respectively, while significantly increased gloss was obtained despite slightly diminished tear and roughness. The antibacterial character of these substrates was confirmed by the substrates displaying a 97% bacteria kill rate.