Understanding Interactions between Cellulose and Phosphate Esters in Papermaking

Linting is a major problem affecting printing processes. It is characterised by the detachment of fibres from paper surface and their accumulation on press blankets. Recently, the addition of blends of phosphate esters to the pulp suspension prior to sheet formation has been identified as an effective way of reducing the linting propensity of paper. The objective of this study was to understand how phosphate esters are retained on cellulosic substrates and how they can contribute to the potential reduction of the linting of paper. Techniques like XPS, MS and conductometric titration were used to give an explanation of this phenomenon. The results tend to confirm the presence of phosphorus on cellulosic substrates and provide evidence of phosphate ester-cellulose linkages. This study allows us to elucidate part of the retention mechanism of phosphate esters in paper and explain their lint reduction ability.