Cationic xylan modified precipitated calcium carbonate filler: preparation, its use in papermaking and evaluation of influence on paper properties

The use of mineral-based fillers in papermaking is a widely studied area due to their ability to enhance paper properties and reduce steam consumption during the drying stage of paper production. However, a significant challenge with high filler addition rates is the poor retention of these fillers within cellulose fibers. To address this issue, various studies have explored filler surface modifications. In this study, xylan (XS), which is readily available from pulp refining and is also environmentally friendly, renewable, sustainable, biodegradable, and biocompatible and is applied as a chemomechanical pulp-strengthening agent for papermaking was cationized through quaternization, and the surface of precipitated calcium carbonate (PCC) was modified accordingly for use in papermaking. The physical and chemical properties of paper samples containing modified PCC were compared to those with unmodified PCC. Results showed that the filler retention capability of the modified PCC was superior to that of unmodified PCC in cellulose fibers. The mechanical and optical properties of hand-sheet papers were also enhanced when filled with modified PCC, which is attributed to the improved compatibility between the cationic XS on the PCC surface and the cellulosic fibers. Enhanced mechanical and optical properties in the paper samples confirmed these improvements. Additionally, Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetry (TG), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Field-Emission Scanning Electron Microscopy (FESEM) were employed to characterize the samples, verifying the successful attachment of XS to the PCC surface. This study proposes a novel approach to filler modification that mitigates the negative interactions between cellulosic fibers and fillers, offering a promising alternative for papermaking applications.