Emulsion stability and sizing performance of alkyl oleate-succinic anhydrides

摘要

Methyl, ethyl, n-propyl and /-butyl oleate esters were reacted with maleic anhydride at high temperature to prepare alkyl oleate-succinic anhydrides (AO-SA). Chemical structures of these compounds were confirmed by NMR. Sizing performance and stability of these AO-SA compounds in aqueous emulsions were compared with those of the conventional alkenly succnic anhydrides (ASA). In the four AO-SA compounds, ethyl oleate-succinic anhydride (EO-SA) showed remarkably higher sizing performance than the others for handsheets prepared by the internal addition of their aqueous emulsions. Sizing efficiency of EO-SA was a little lower than that of ASA for the handsheets prepared without PCC filler, whereas it became similar to or somewhat higher than that of ASA for the handsheets prepared by the internal addition to pulp slurries containing 10% PCC filler. EO-SA had higher stability in the aqueous emulsion than ASA, and sizing degree was mostly unchanged for the handsheets prepared by the addition of the EO-SA emulsion to pulp slurries even after one day from the emulsion preparation, while nearly no sizing features were observed for the handsheets prepared with ASA under the same conditions. Hydrolysis behavior of EO-SA and ASA was monitored at either pH 7 and 9, and EO-SA had clearly higher resistance to hydrolysis in both pH values. These results indicate that EO-SA has some potential to be used for internal and/or surface sizing partly in place of the conventional ASA or AKD.