Mini-Encyclopedia of Papermaking Wet-End
Part Two: Definitions and Concepts
The word "polyelectrolytes" is a general term for water-soluble molecules comprised of many repeating units. As the name implies, most such materials of interest to papermakers have a significant level of electical charge. In other words, small ions dissociate from the macromolecule, leaving a net charge associated with the chain. Many polyelectrolytes of interest to papermakers are linear, as in the case of cationic amylose starch. This compound makes up 28% of dent corn starch and 21% of potato starch. These starches are used to make cationic starch for wet-end addition. Many other polyelectrolytes are branched, as in the case of polyethyleneimine (PEI). Also, most starch products contain a majority of branched molecules called amypolypecin. Cationic starch produced from waxy maize is about 100% branched molecules. Soluble aluminum products such as alum and PAC are often considered to be polymeric because of the formation of oxygen bridges between the aluminum ions (olation) during use.
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This page is maintained by Martin hubbe, Associate Professor of Wood and Paper Science, NC State University, firstname.lastname@example.org .