Study on polymerization of nonsoap polysiloxane-acrylate emulsion by redox initiation

Study has been made on polymerization of nonsoap acrylate emulsion and organosiloxane modified nonsoap acrylate emulsion using sodium undecylenate(NaUA) as surface active monomer and K2S2O8 /NaHSO3 as redox initiation system adopting seed emulsion method. The effect of polymerization conditions including reaction temperature,the amount of NaUA and the effect of presence of organosiloxane on polymerization and property of the emulsion was studied systematically. The study result indicates that acrylate emulsion is very stable during the emulsion polymerization and storage when the addition of sodium undecylenate is 3% and reaction temperature is 70 ℃. The organosiloxane modified nonsoap acrylate emulsion is relatively difficult to synthesis. Yet a stable nonsoap polysiloxane-acrylate emulsion can be obtained under redox condition. TEM showed that the emulsion particle is in uniform core-shell sphere structure when the organosiloxane was added in the beginning and the emulsion particle shape is irregular when the organosiloxane was added in the end. Water resistance of nonsoap emulsion is much better than that of relevant emulsion containing emulsifier.