Sa. Fischer, STRUCTURE AND WET STRENGTH ACTIVITY OF POLYAMINOAMIDE EPICHLOROHYDRINRESINS HAVING AZETIDINIUM FUNCTIONALLY, Tappi journal, 79(11), 1996, pp. 179-186
The wet tensile strength of paper made with polyaminoamide-epichlorohy
drin (PAE) was found to depend on the resin's relative equivalent weig
ht based on azetidinium, the most reactive cross linking group in the
resin. The wet tensile strength of PAE treated paper increased as a fu
nction of increasing relative azetidinium equivalent weight for a seri
es of PAE resins having different molecular weights and quaternary cha
rge densities. This relationship may be used to predict the relative o
rder of performance between PAE resins on paper machines. The structur
e-activity relationship was observed with wet tensile data from papers
made on a pilot fourdrinier paper machine and the same trend was obse
rved in commercial papermaking operations. A laboratory handsheet meth
od did not distinguish any differences between the PAE resins. The rel
ative molecular weights of the resins were determined by size exclusio
n chromatography (SEC) and the relative azetidinium content was measur
ed by nuclear magnetic resonance (NMR) spectroscopy.