High-yield grafting of carboxylated polymers to wood pulp fibers

Poly(ethylene-alt-maleic acid), PEMAc, is a linear polymer that, along with its isomer polyacrylic acid, has the highest carboxylic acid content of any polymer. The goal this work was to elucidate mechanisms that control amount PEMAc permanently fixed on pulp fibers after impregnation dry dilute solution followed by drying/heating (curing). Two which cellulose were discovered, chemical, and physical fixation. With room temperature drying only fixation operative. Evidence supports explanation consequence slow swelling dissolution thick dried deposits fiber surfaces. Chemical includes grafting plus enhanced cohesion within layers, possibly due interchain crosslinking. pH determines mechanism for curing temperatures above 100 °C. Physical dominates when > 8 whereas chemical values ≤ 7, suggesting reactions require partial or complete protonation succinic moieties. yield impregnated washing depends upon mechanism. When dominates, yields low high molecular weight doses less than 0.1 meq/g (6.3 kg PEMA/tonne pulp) close equaled 100%. By contrast, primary fixation, are ~50% 0–20% MW PEMAc. These results show can be achieved under conditions could implemented in machines producing market pulp.