Polysiloxanes with Quaternary Ammonium Groups for SPPO Aqueous Emulsions

Abstract

AbstractIn this paper, polysiloxanes with pendant quaternary ammonium groups (QAPS, cationic silicone surfactants) were synthesized through hydrosilylation of poly(dimethylhydro)siloxane with allyl glycidyl ether, then ring‐opening reaction of epoxide groups with diethyl amine and quaternization with benzyl chloride. The chemical structures of QAPS and intermediate products were characterized by 1H NMR and FT‐IR. The surface and thermal properties of QAPS were researched through surface tension measurement and differential scanning calorimetry analysis. The results showed that the QAPS had reduced critical micelle concentration values and lowered glass‐transition temperatures (Tg). Waterborne silyl‐terminated polypropylene oxide emulsions were prepared via phase‐inversion emulsification using QAPS and polyoxyethylene octylphenyl ether (OP‐10) as composite emulsifiers and poly(ethylene glycol) ( = 400, PEG 400) as cosolvent. The electrical properties of the system indicated that the phase inversion was completely accomplished. The emulsions with smaller particle size (6.2 μm) had better storage stability (47 days at 50 °C) and freeze–thaw stability.