关键词: 硅油乳液, Pickering, COD, 稳定性, 协同稳定, 纰裂

Abstract: Silicone oil is widely used in textile, leather, paint and other industries. In the textile industry, silicone oil is mainly used in the finishing of textiles, giving fabrics soft, smooth, fluffy and other feel. In printing and dyeing processing, it is often necessary to use silicone oil in the form of emulsion. Taking the common amino silicone oil as an example, on the one hand, soft finishing will bring smooth and soft feel to the fabric, but also make the fabric appear serious slipping, affecting the service life of the fabric; On the other hand, due to its high relative molecular weight and high viscosity characteristics, the dispersion stability of the emulsion is poor. In this paper, the copolymer emulsion particles of isooctyl acrylate (EHA) and methyl methacrylate (MMA) were prepared by semi-continuous seed emulsion polymerization and used as Pickering particles. Pickering silicone oil emulsion stabilized with nanoparticles and emulsifier was prepared to improve the stability of the emulsion and reduce the amount of emulsifier. The resulting emulsion was used in fabric finishing. The effects of Pickering silicone oil emulsion and emulsifier stabilized silicone oil emulsion on the chemical oxygen demand (COD) and the properties (feel, stitch, etc.) of finished fabrics were investigated.
Firstly, the hydrophilicity of Pickering granule latex was evaluated by testing the water contact Angle of the film. The results are shown in the bar chart. The contact Angle test shows that the water contact angles of PEHA, P(EHA-MMA) and PMMA are 88.1°, 88.5° and 89.6° respectively, which are all close to 90°. According to the free energy formula of all three kinds of spherical particles on the "oil/water" interface, they can be adsorbed on the "silicone oil/water" interface to form a stable adsorption layer. Gives Pickering silicone oil emulsion high dispersion stability. In order to obtain a stable emulsion, when the emulsifier is stabilized alone, the amount of emulsifier is as high as 24% of the mass of silicone oil (Table 2). It can be seen from Table 2 that the silicone oil emulsion can be stabilized when only 8% emulsifier and 6% nanoparticles are used in the cooperative stabilization system, indicating that the Pickering emulsion system has a high stabilization efficiency
The emulsification system also has significant influence on the COD value of the working liquid before and after finishing and the feel and stitch property of the finished fabric. When emulsifier is used alone to stabilize the emulsion, the COD value in the finished residue increases sharply with the increase of the emulsifier dosage. Studies have shown that the method of increasing the amount of emulsifier to improve the dispersion stability of the emulsion will lead to a large amount of silicone oil remaining in the residual liquid, which will not only cause the waste of additives and the burden of sewage treatment, but also lead to the deterioration of the feel of the finished fabric (Table 3). By replacing the emulsifier stabilization system with the Pickering emulsion system, the surface friction coefficient of the fabric is lower, the feel rating is 4-5, and the COD value in the finished residue is lower. P (EHA-MMA) nanoparticles not only guarantee the feel of the finished fabric (Table 3), but also make the fabric have good skid resistance.

Key words: silicone oil emulsion, Pickering, COD, stability, synergistic stability, slippage