Effect of paper-making additives on biodegradation of lignocellulosic fibers

The biodegradation kinetics of paper materials with various chemical additives was studied, focusing on their potential tunability. Paper materials with additives, including retention aid, hydrophobic agent, and wet and dry strength agents, were explored in two forms: disintegrated fiber and paper form. Using the Gompertz equation, biodegradation kinetics were modeled to calculate the lag phase, initial biodegradation rate, and ultimate biodegradation extent. All paper materials showed higher biodegradation extents than microcrystalline cellulose (MCC) due to the highly biodegradable nature of hardwood bleached pulp. Disintegrated paper materials exhibited similar lag phase values and ultimate biodegradation to MCC regardless of treatment, while punched paper materials showed noticeable differences, suggesting that fiber disintegration plays a critical role in initiating biodegradation. Hydrophobic and wet strength treatments, such as alkyl ketone dimer (AKD) and wet-strength agents (PAE), respectively, significantly increased the lag phase, but their ultimate biodegradation extent remained intact. These findings highlight that the biodegradability of paper materials can be preserved even after chemical treatments, underscoring their environmentally friendly potential.