The Modification Of Nano-ZnO By CDI Activated Cellulose And Its Application In Coating

Nano-ZnO is a new kind of inorganic functional material, which has larger specificsurface area and wider energy tape so it can be extensively used for a variety ofapplications in magnetic, optical, electrical and other fields, compared with thetraditional ZnO. Nano-ZnO has applied preliminary in the field of the functionalcoatings.So far the reaserch of protective effect of nano-ZnO modified coating has beenstill at an exploratory stage inland and abroad. In particularly, the influence ofanti-infiltrate of media of the nano-ZnO modified coating remains at a simplequalitative stage. Addition, the systematic quantitative research is rare. And for thehydropuilicity, it is hard to break up uniform in resins. What it is more, for the strongactivity of nano-ZnO,the conglobation will happen easily.So it is necessary to modifythe surface of nano-particle.In this topic the CDI activativate cellulose, which grafting with the nano-ZnOsurface modified by the silane coupling agent. So that the modified in nano-ZnOorganic solvents has good dispersion and stability. This article firstly solve the problemsof the reunion of nano-ZnO and its poor combined ability with coating, and then studiedthe modified nano-ZnO on polyester film about bibulous rate, adhesion and the otherproperties of the influence.Comparied with the unmodified nano-ZnO, the grafting rate of modified nano-ZnOwhich grafted with the CDI activated cellulose is greatly improved, and the particle sizeis uniform between60~80nm. And through the settlement experimental results, it isknown that the modified nano-ZnO solved in organic solvents can maintain72h above.The sedimentation performance was more stable, better dispersion. Through the resultsand analysis of infrared spectrum, thermo-gravimetric experiments, we can concludethat the cellulose activated with CDI react with the nano-ZnO by the process of silanecoupling agent. The experiment of activation index and absorbency analysis researchabout the modification conditions such as the content of coupling agent, coupling time,reaction temperature, the quality proportion between cellulose and CDI，the dosage ofcellulose-CDI to the influence of modification effect, contrast with the unmodifiednano-ZnO.So that the optimum technological conditions of modifying nano-ZnO were:he coupling agent content of2%, reaction temperature of60℃, the proportion ofcellulose with CDI of1.25, the cellulose-CDI amount of3%. We preparied ZnO/polyester nano coating through the blending method by theunsaturated polyester coating filling with the particles of the modified nano-ZnO andunmodified nano-ZnO. And we test the film properties of ZnO/polyester nano coatingsuch as water resistance, hardness, adhesive force, acid and base resistance. We researchabout the addition quantity to the performance of the film properties. And the test resultsof film properties show that the properties of the unsaturated polyester coating havebeen improved to some extent when the modified particles were added. The additionquantity of nano-ZnO is3%. Furthermore, the mechanism of nano-ZnO modifying theunsaturated polyester film is also discussed.