NEW INSIGHTS INTO THE TOPOCHEMISTRY OF RECYCLED PULPS
The topochemistry of recycled de-inked pulps made from old newspaper (ONP) and mixed office waste (MOW) was investigated by X-ray photoelectron spectroscopy (XPS) and Time-of-flight secondary ion mass spectrometry (ToF-SIMS). The short and the long fibre fractions of the pulps were separated and their differences in surface chemistry were assessed. The amount of surface anionic groups (SAG) and the surface coverage by carbohydrates, lignin, and extractives were calculated from the XPS measurements. Metal traces were observed on feed pulps and the fines fractions of both ONP and MOW, some of them exposed after extraction. Only fines of ONP showed a quantifiable amount of surface extractives. The amount of surface lignin did not differ significantly between the ONP fractions. The method presented high values of surface lignin on MOW, especially fines fraction, which was considered in fact a measure of other surface contamination. There were no remarkable differences between the SAG’s in the different fractions. Residual chemicals from paper converting, printing and de-inking were detected on the fibre surfaces by ToF-SIMS spectrometry. The distributions of trace metals (e.g. Fe, Al, and Mg), pulp components and some common contaminants were assessed using ToF-SIMS imaging. It was discovered that the fibre surfaces were covered by patchy ink residuals at raster sizes of 200 μm x 200 μm. A uniform layer of siloxanes and phthalates was also detected on every sample. The residual paper and printing chemicals can affect interactions in papermaking and reduce the fibre-to-fibre bonds in the recycled paper.
recycled fibre de-inked pulp surface chemistry XPS ESCA ToF-SIMS
Pedro Fardim Elina Orblin
Lab. of Fibre and Cellulose Technology, (A)bo Akademi University, Porthansgatan 3, FI-20500, Turku/(A)bo,Finland
国际会议
广州
英文
717-720
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）