2024, Tomkowiak, Karolina, Mazela, Bartłomiej, Szubert, Zuzanna, Perdoch, Waldemar

The need for sustainable, biodegradable materials to address environmental challenges, such as oil-water separation, is growing. Cellulose-based absorbents offer an eco-friendly alternative to synthetic materials. However, their hydrophobicity must be enhanced for efficient application. In this study, cellulose-based sorbents derived from Kraft and half-bleached chemo-thermomechanical pulp (BCTMP) were hydrophobized using silanization and alkyl ketene dimer (AKD) techniques. Hydrophobic properties were successfully imparted using methyltrimethoxysilane (MTMOS), n-octyltriethoxysilane (NTES), and N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane (AATMS), with water contact angles ranging from 120° to 140°. The water sorption capacity was significantly reduced to below 1 g/g, whereas the oil sorption capacity remained high (19–28 g/g). The most substantial reduction in water vapor absorption (3–6%) was observed for the MTMOS- and AATMS-silanized samples. These results demonstrate the potential of hydrophobized cellulose-based sorbents as sustainable alternatives for oil-water separation, contributing to environmentally friendly water treatment solutions.

2024, Szubert, Zuzanna, Mazela, Bartłomiej, Tomkowiak, Karolina, Grześkowiak, Wojciech

This article presents the results of flame-retardancy tests conducted on cellulose sheets produced using a Rapid Köthen apparatus treated with retardants. The agents used were potassium carbonate (PC) K2CO3 (concentrations of 20; 33.3; and 50% wt/wt), monoammonium phosphate (MAP) NH4H2PO4 (concentrations of 35% wt/wt), diammonium phosphate (DAP) (NH4)2HPO4 (concentrations of 42.9% wt/wt), and bisguanidal phosphate (FOS) C2H10N6 (concentrations of 22.5% wt/wt). The agents were used to improve Kraft cellulose-based sheets’ flame-retardant properties and compare their performances. As part of the study, the flammability of the materials was determined by the following methods: an oxygen index (OI) test, a mass loss calorimeter (MLC) test, and a mini fire tube (MFT) test. All formulations showed an increase in flame retardancy compared to the control test. All protected samples were non-flammable for OI determinations, and DAP-protected samples showed the highest OI index. For the MLC test, DAP-protected and MAP-protected samples showed the best heat-release rate (HRR), total heat release (THR), and average heat-release rate (ARHE) (samples did not ignite for 600 s). In the MFT test, all treated samples had comparably reduced weight loss. The best parameter was achieved for MAP and DAP (15% weight loss).