Tunable Micro-structure Of Polyacrylate/ZnO Nanorod Composite Emulsion And Its Properties Study

The use of polyacrylate is up to 70% in leather finishing agent due to its excellent properties.However,existing polyacrylate coating products expose many defects,for example,densification of coating seriously hinders the hygienic performance of leather products and polar groups of coating reduce its water resistance.One-dimensional nano-ZnO,which has good mechanical properties,hygienic properties and antibacterial properties,has potential value for overcoming the defects of polyacrylate coating materials.In this research,the performance of polyacrylate films was improved as a measurable indicator,and ZnO nanorods were introduced into polyacrylate emulsion by physical blending and in situ method,respectively.In the process of polyacrylate emulsion preparation and film formation,the change of the morphology of ZnO nanorods and the structure of composite latex was investigated systematically.The relationship between the distribution of ZnO nanorods and the properties of films was established.ZnO nanorods were prepared by one-step calcination method,whose length and diameter were 3 to 5 μm and 30 to 50 nm,respectively.The polyacrylate/ZnO nanorod composite emulsion was synthesized by physical blending method.The results showed that the microstructure of the composite emulsion was the surface of latex coated by ZnO nanorods.The change of structure of composite latex and the distribution of ZnO nanorods was affected by the following factors: solid content > stirring rate > reaction time > reaction temperature > pH value.When the aggregation behavior of ZnO nanorods was serious in the films,water vapor permeability of the composite films was improved obviously,but mechanical properties and water resistance were poor.When ZnO nanorods were well dispersed in the composite films,water resistance and mechanical properties of the composite film were improved,but the water vapor permeability was poor.The polyacrylate/ZnO nanorod composite emulsion was synthesized using in situ method.The results showed that Zn O nanorods were introduced at the seed stage,the decrease of the ratio of SDS to Span80,or the use of DNS-86 reactive emulsifier,the above conditions can make the nano-ZnO into the latex.When the ZnO nanorods were located outside the latex,tensile strength and water vapor permeability of the composite films was excellent,but elongation at break of the composite films was poor.When the ZnO nanorods were located in the latex,elongation at break and water resistance of the composite films was improved,but tensile strength of the composite films was poor.