Study On The Relationship Of Structure And Adsorption Performance Of Silicones

Silicone is a type of textile finishing agents which applicated in the dyeing and finishing industry. It can make fabric with features such as soft, smooth, breathable, wear comfortable, etc.and be used for water-proof, softening, anti-fouling, anti-static and antibacterial anti-mildew finishing in order to improve the performance of fabric and enhance the value of the fabric. However, due to the molecular structure of silicones, the adsorption on the fiber does not have an absolute advantage, therefore, silicone may adsorp and deposite on the finishing machinery in addition to the fiber surface adsorption in the process of processing and washing, as a result,it will not only reduce agent utilization, but also may lead to equipment problems. In addition, the effects stability of silicone finishing agent is also related with the adsorption performance of fibers and fabrics. Therefore, it has a very important practical significance to research the adsorption performance of different structures of organic silicon on the substrate.The issue is to study deposition and adsorption performance at different substrate in the fabric/clothes washing process after washing through simulation experiments according to Procter & Gamble Company's project proposals. Using improved silicon-molybdenum blue spectrophotometric method to obtain trace silicon amounts in the fabric,wall and in the liquid. And then explore the relationship between silicone structure and its adsorption and deposition performance through analysis and comparison.Firstly, the silicon-molybdenum blue spectrophotometric method is improved based on the choice of wavelength, stability of color liquid, pH and other factors of the methodology. As a result, a linear correlation coefficient of 0.997159 of the standard curve is obtained, relative standard deviation is less than 2% and the recovery is 98%~102%. It improved the stability and accuracy of the method which could meet the need for silixone trace analysis.Secondly, deposition and adsorption performance of silicone in the fabric, wall and in the liquid is study. It is showed that there is low utilization problems because the adsorption percentage of the fabric is 43% to 66%, 0.5% to 4% on the device wall, 32% to 54% left in the solution. As the silicone molecules reactive with cotton fiber, amino-modified silicone can be absorpted more on cotton fabrics generally, in which polyether—amino modified silicone microemulsion (SLM21-200 Modified) has maximum adsorption in the fabric distribution ratio and adsorption capacity. The Coulomb force, not only van der Waals force between silicone and fibers, the polar groups hydrogen bonding, but also the molecular polarity of silicone and silicon particle size and size distribution influence the silicone adsorption properties. The results showed that stronger the silicone polarity, polar groups as the end-group, the worse the water soluble character, the much more silicone adsorption on the walls.Finally, the washing fastness of different structures of organic silicon on different fabrics is studied. It is found that the polydimethylsiloxane emulsion washing fastness is poor bacause it has no active groups, only rely on interactions between molecules attached to the cotton fiber surface; while the washing fastness of amino-modified silicone in the cotton fabric is generally good, especially amino-modified X-22-8699-5S is best. The study on the washing fastness of same types of organic silicon on polyester fabric showed that the washing fastness of polyether-modified silicone and poly dimethyl siloxane is poor; polyether-amino modified silicone micro-emulsion the best; amino-modified silicone is generally good, the washing fastness enhanced with the increase of amino functional groups.There is a practical significance to study the silicones adsorption on fabric and deposition in walls, which provides a theoretical guidance to technology application.