Application Of Sulfonic Gemini Surfactant On Silicone Emulsion Polymerization

This thesis gave emphasis to the research progress and the mechanism of ring-opening emulsion polymerization of octamethylcyclotetrasiloxane (D4) and reviewed the property and the synthesis of gemini surfacants. We discussed the technics of the silicone emulsion polymerization, And to achieve the purpose of modification, on the basis of the emulsion polymerization of D4, the functional groups of amine, epoxy and piperazine were successfully introduced to the emulsion, then the modified silicone emulsion was applied on finishing treatment of the polyester fabric.In the study of ring-opening of D4 emulsion polymerization. The novel silicone emulsion was synthesized by ring-opening polymerization of octamethyl-cyclotetrasiloxane (D4) by continuous addition of monomer using sulfonic gemini surfactant (6,6'-(butane-1,4-diylbis(oxy))bis(3-nonylbenzenesulfonic acid)) as an emulsifier (catalyst). The influences of reaction conditions on D4 ring-opening polymerization including reaction temperature, the amount of emulsifier and reaction time respectively to latex particles, conversion rate, viscosity average molecular weight and mechanical stability were studied. When the surfactant was used in 10% of weight percentage to D4, the polymerization was carried out at 85℃for 8 h and then at 25℃for 12 h to give polysiloxane(PDMS) as a transparent and stable emulsion. The viscosity average molecular weight of PDMS reached 2.38x 105 g/mol.In order to give silicone emulsion more application performance, three kinds of modified silicone emulsions were prepared by ring-opening polymerization of D4 and co-polymerized with silane coupling agents (trimethoxy(3-(oxiran-2-ylmethoxy)-propyl)silane (KH-560),N1-(3-(dimethoxy(methyl)silyl)propyl)ethane-1,2-diamine (KH-602) and (dimethoxy(methyl)silyl)propyl)piperazine (KH-029)). We found that as the amounts of the silane coupling agent increased, the average particle size of the latex became big, the conversion of D4 decreased gradually, and reached balance when the amount of the siliane coupling agent was up to 3%.The modified silicone emulsions were applied to finish the polyester fabric, and the properties including whiteness index, hydrophilicity and softness were studied. We found that as the amount of the silane coupling agent KH-560 increased, the fabric's whiteness index was decreased, but the decline was very small; hydrophilicity and soft hand of the polyester fabric were both increased. As the amounts of the silane coupling agent KH-602 increased, the fabric's whiteness index was decreased sharply, it's hydrophilicity dropped dramatically and hydrophobic was increased gradually. As the amounts of the silane coupling agent KH-029 increased, the fabric's whiteness index and hydrophilicity were both decreased obviousely, the soft hand was improved, but was worse than the silane coupling agent KH-602.