Synthesis Of N,N-Dimethyl Dodecyl Quaternized/Polyether Modified Silicones And Their Application As Antibacterial Fabric Finishing Agent

Recent years, as human health is threatened by infectious diseases such as SARS andH IN 1 influenza, people show large interests in textile products with antibacterial function.And there is also an urgent need. Silicone oil is a good finishing agent for fabrics. It has low surface energy and goodfilm-forming ability and is thus able to make textile softand smooth. It has been found that polyether and polysiloxanecopolymer can give fabrics good properties. It is also easier to be controlled than other types of silicone oils. Therefore, in this paper, quaternized/polyether comodified silicones were synthesized and analyzed. The aim is that the synthesized silicones can give cotton fabrics both softness and antibacterial properties.When quaternized/polyether comodified silicones have random block structure with many polyether and polysiloxane chains, the viscosity of the silicones may become very high, which is not convenientfor storage and emulsification.In order to avoid above problems, we modified the end of polysiloxane chains and produced two types of quaternary silicones.The antibacterial capability and application in cotton fabrics as softeners of the silicones were discussed.In the first part, N, N-dimethyl dodecyl quaternized/polyether modified silicones (silicone oil A) and N, N-dimethyl dodecyl quaternized silicones (silicone oil B) were synthesized. The structure of silicone Aand B was confirmed by 1HNMR, FTIR and TG.After silicones were emulsified and applied to cotton fabrics, their properties including softness, whiteness, wettability, and hydrophilicity were characterized. The commercial antibacterial agent product (names as C) was also compared with the synthesized A and B. It was found that both silicone A and B can give cotton fabrics good softness and hydrophilicity, while commercial product C gave fabrics very hydrophobic surface and was unable to improve the softness. Therefore, the commercial antibacterial agent C can not be used as fabric softeners but the synthesized can be used as fabric softeners.In the second part, antibacterial properties of silicones, their emulsions and treated cotton fabrics weretested and discussed. Agar diffusion method and bactericidal testwereadopted. The antibacterial mechanismwas also discussed. The results showed that both silicone A and B,their emulsions and treated cotton fabrics hadeffectiveantibacterial properties to staphylococcus aureus and E coli.Some of the synthesized silicones even showed equal antibacterial property with commercial antibacterial product C. In addition, it was found thatthe finishing cotton fabrics still showed good antibacterial effects after being washed once.