Highly Sensitive Sizing Response Induced by 2-Bromination of Fatty Acids and their Pairing with Anchor Sites Formed on Paper Surfaces

摘要

The base handsheets were prepared from a pulp suspension containing either aluminum sulfate (alum) or polydiallyldimethylammonium chloride (PDADMAC), followed by being soaked in the chloroform solution of stearic and palmitic acids (SPA), which were brominated, or non-brominated, at the a-carbon positions adjacent to respective carbonyl groups. No sizing effect was observed in the absence of alum or PDADMAC, and thus these additives that form anchor sites for size components were indispensable for sizing appearance. Besides, extremely different sizing responses were found, strongly depending on the combinations of fatty acids and additives. Alum-treated handsheets showed good sizing effects by dipping them in an SPA/chloroform solution ; however sizing with 2-brominated SPA (Br-SPA) had no contribution to sizing appearance. By contrast, PDADMAC-handsheets sized with Br-SPA exhibited high sizing degrees, although there was no sizing effect in the case of using non-brominated, original SPA. Highly sensitive sizing responses would provide a new insight to elucidate paper sizing mechanisms.