Study Of Polymer-based Composites Coating On NiTi Alloy Orthodontic Wire

With TiO2as the paint preparation polytetrafluoroethylene (PTFE)/polyperfluoro propylene (FEP) composite coatings on NiTi alloy teeth corrective wiressurface by dipping technique in this paper. The surface morphology, phase, elements,hardness, wear resistance and adhesion respectively of the coating were investigatedby scanning electron microscopy (SEM), X-ray diffraction (XRD), infraredspectrometer,hardness swinging rod, adhesion tester, wear tester,in addition,variousprocess parameters effect on the he surface characteristics and the mechanicsproperties of the coating were discussed.At the same time acute toxicity tests wereconducted to the coating and investigated its biocompatibility.The results showed that adding the dispersant,using the pigment of suitableparticle size and improving the coating environment could effectly prevent theoccurrence of the drawbacks such as crack, needle hole, coarse face and ununiformityin thickness.The results indicated that the coupling agents for improving the mechanicalproperties of the coating is effect,and the effect on the adhesion enhance silanecoupling agents is better than titanate coupling agents in aspects of enhance coatingadhesion. In this test,silane coupling agent by using the whole mixing method,it’soperation is relatively simple than the surface treatment method and and the syllepses,in addition to this,the properties of the coating can be attached to achieve the best.When the coupling agent to be the volume of resin of2％the bond effect will get thebest. Hardness,wear resistance and adhesion respectively of the coating wereenhanced with TiO2content increases; the optimal content of TiO2was in the rage of12.5％-15％,too much will result in a reduce of the above mechanical properties.Inthe colored paint FEP as the PTFE adhesive to enhance the coating adhesion, at thesame time,the coating friction and wear behavior can be improved when the mixtureof the two compounds in the varnish. The results showed that the PTFE/FEP coatings not only were nontoxic andbiocompatible,but also provided with the aesthetic property for the metal color ofteeth corrective wires has been covered completely with them.