Preparation Of Nano-iron Oxide Pigment And Nano-composite Coatings

The preparation of Nanoparticle a -iron oxide and it' applying in epoxy powder coating are studied in this dissertation. XRD, TGA-DTA, FT-IR, TEM are used to identity the products and there are three methods in preparing nanoparticle a -iron oxide: colloidal chemical, solid phase reaction and supersonic homogenous precipitation method. Through exploring respectively the reaction conditions by monofactor experiments the optimal condition is established. The optimal reaction condition of the colloidal chemical method is like the following: the system of 0.3mol/L FeCl3 and NH3 H2O undergoes reaction with 4.0g surfactant SDBS(40%) at pH 4-8 and Temp 60~70℃ for 40min. In the reaction straight branch pipe three-outlet Bunsen flask and the double mixer with propeller are best and 30mL organic solvent chloroform is used as extractant. The results show that the homogenous spindle type particles are a -FeOOH with the average major axial diameter of 25nm and the minor of 10nm. The a -FeOOH is changed into a -Fe2O3 by calcining at 400℃ . The solid phase reaction method is as follows: the system of FeCl3 6H2O and NaOH(l:3) undergoes reaction with surfactant Tween-80 and the precipitate is washed by supersonic water. The results show that the homogenous spindle type particles are a -Fe2O3 with the average major axial diameter of 30nm and the minor of 6nm. The supersonic homogenous precipitation method is like: with 10 minutes supersonic vibration the system of 1.0mol/L Fe(NO3)3 and CO(NH2) 2 (1:3-1:4) undergoes reaction for 2h at 80!. The results show that the homogenous spindle type particles are a -Fe2O3 with the average major axial diameter of 10nm and the minor of 5nm. The epoxy powder coating is prepared from a -Fe2O3, epoxy resin, novolac resin, promator and so on which are mixed in the mixing roll and are smashed by multi-purpose smashing equipment. The reunification phenomenon in epoxy powder coating is overcome by supersonic beforehand dispersion and the synthetic property of the epoxy powder coating is also determined. The aging test of epoxy powder coat is done by the artificial exposure to ultraviolet.