Synthesis And Application Investigation Of Polyacrylate Soap-free Emulsion

When the traditional polyacrylate emulsion containing a large number of small molecule emulsifiers which cause water resistance, cohesion and strength of the films decline, are used as pigment printing and dyeing adhesives, the wet rubbing fastness of finished fabric are not good enough. Although the above shortcomings can be improved by emulsifier-free emulsion, the stability and solid content of the emulsion prepared by traditional soap-free emulsion polymerization technology are low. In order to solve the problems effectively, emulsifier-free polymerization was studyed by pre-emulsified and semi-continuous adding method with small quantities of the self-made polymerizable emulsifier in this paper. However, the polyacrlate soap-free emulsion also have some disadvantages, for example, it is brittle under freezing and viscous under warming, which causes a conflict between fastness and hand feeling of the fabric. Polyacrylate soap-free emulsion was modified by organic silicon with excellent softness, low viscosity and surface tension so as to resolve this contradiction, and the final emulsifier-free emulsion shows excellent application performance.In the paper, the soap-free emulsion was synthesized by methyl methacrylate, iso-octyl acrylic, butyl acrylate, 2-hydroxyethyl acrylate and acrylic acid. According to the single factor experiment, the best conditons for the polymerization reaction were determined: reaction tempreture was 80℃, mass ratio of the polymerizable emulsifier B/A was 10︰ 0, dosage of the anionic and nonionic composite polymerizable emulsifier B was 0.4% (on weight of total monomers, the same as below) , dropping time of pre-emulsion was 1h, holding time was 1h and dosage of initiator KPS was 0.4%.In the application experiment of soap-free emulsion, the optimum conditions for printing and dyeing were confirmed by analyzing the factors with baking temperature, baking time and dosage of the adhesive, which affecting performance of pigment printing and dyeing (such as fabric feel, softness, wet and dry rubbing fastness and the K/S values). The softness, whiteness and pilling resistance were studied by changing dosage of vinyl silicone oil, dosage of the silicone-acrylate soap-free emulsion and different Tg of polyacrylate soap-free emulsion.The physical and chemical properties of self-made soap-free emulsion were evaluated by testing appearance and all kinds of stabilities of the emulsion, and the structure, Tg, thermal properties, particle morphology and size distribution of the self-made soap-free emulision were determined according to FT-IR, DSC, TG, TEM and laser particle size analyzer.The results shows that the self-made soap-free emulsion has high solid content and good stability, and the sele-made soap-free emulsion has basically reached the industrial application effect, especially the fabric softness and feel were improved obviously with silicone-acrylate soap-free emulsion compared with polyacrylate soap-free emulsion. Therefore, the self-made soap-free emulsion is expected to become a set of multifunctional dyeing and printing auxiliary with pigment printing, dyeing, softness (for pigment dyeing fabric) and pilling resistance.