| Conductive coatings have many important applications in various fields of nationaleconomy. Traditional conductive coatings were prepared by mixing inorganic conductivefiller and organic resin. Because of poor compatibility of the inorganic phase and the organicphase, the filler can not disperse well in the resin. Therefore, more fillers have been added toresin to achieve good conductivity. However, it will make the mechanical properties worseand increase the cost of the coatings. In consideration of the disadvantages of inorganic filler,in this thesis, the conductive polymer materials were selected as conductive filler. Due to thefast curing and environmental friendly of the UV-curable technology and good film-formingproperties of polyurethane materials, UV-curable polyurethane were selected as film-formingresin, which mixed with conductive polymer filler to synthesize the UV-curable conductivecoatings.In the first part, the UV-curable waterborne sulfonates polyurethane acrylates(SWPU)was synthesized by using PCDL which molecular weight is2000, isophorone diisocyanate(IPDI),2,4-diamino benzene sulfonate(DASS) and hydroxyethyl methacrylate(HEMA) as themain materials. The structures of SWPU were characterized by FT-IR. The SWPU/PEDOTaqueous dispersion was prepared by emulsified SWPU and3,4-ethylenedioxythiophene(EDOT). The conversion of EDOT and the particle sizes of different molar ratios were tested.The test results showed that when the molar ratio of SWPU and EDOT was1:1, the time wasshortest as EDOT reacted completely, and the shortest time was6h. The higher the molar ratio,the lower the conversion rate; the particle sizes of SWPU/PEDOT aqueous dispersionincreased when the molar ratio of SWPU and EDOT decreased, and the minimum particlesizes were260nm when the molar ratio of SWPU and EDOT was4:1, the maximum particlesizes were380nm when the molar ratio of SWPU and EDOT was1:1. After dried the aqueousdispersion, then UV-cured it to form the films, the relevant properties of the coating filmswere analyzed. The results showed that, the coating films have good conductivity when themolar ratio of SWPU and EDOT was2:1and the film thickness was100μm, the surfaceresistivity of the coating film was2×104Ω/cm2, the thermal stability and water resistance weregood in this ratio, the adhesion was1, the pencil hardness was H.In the second part, the UV-curable polyurethane acrylates(PU) was synthesized by PCDL,IPDI,1,4-butylene glycol(BDO) and HEMA. The structures of SWPU were characterized byFT-IR. The PPy-DBSA conductive particle was synthesized by pyrrole(Py), dodecylbenzenesulfonic acid(DBSA) and ammonium persulphate(APS). The results showed that, thePPy-DBSA particle sizes increase when the molar ratio of Py and DBSA increase. The bestconductivity of PPy-DBSA was1.27S cm-1when the molar ratio of Py and DBSA was2:1,and the PPy-DBSA particle sizes were51nm. The PPy-DBSA mixed with PU, then addedreactive diluent and photoinitiator to synthesize the UV-curable conductive coatings. Thebasic properties of the coating films were analyzed after UV-cured. The results showed that,the coating films owned better conductive performance when the PPy-DBSA content was20wt%and the films thickness was80μm, the surface resistivity of the films was360Ω/cm2; To got the best UV-curable effect, the ratios of photoinitiator819and KIP160were3wt%and2wt%, the curing time was40s; The coating films had the best basic performances whencontaining40wt%PU,15wt%SM6621,10wt%TMPTA and10wt%TPGDA. The tensilestress was7.6MPa, the tensile strain was23.6%, the adhesion was0, and the pencil hardnesswas3H.In the third part, The GN-PPy conductive particle was synthesized by graphene(GN), Py,DBSA and APS. The morphologies and diameter of GN-PPy nanoparticle were characterized byTEM and SEM. Conductivity results showed that the conductivity of GN-PPy was best whenGN content was30%, the best conductivity was4.35S cm-1. The GN-PPy mixed with PUwhich was made in the second part, then added reactive diluent and photoinitiator to synthesisthe UV-curable conductive coatings. The basic properties of the coating films were analyzedafter UV-cured. The results showed that, the coating films owned better conductiveperformance when the GN-PPy content was15wt%and the films thickness was80μm, thesurface resistivity of the films was75Ω/cm2; To got the best UV-curable effect, the ratios ofphotoinitiator819and KIP160were3wt%and2wt%, the curing time was40s; The coatingfilms show the best basic performances when containing45wt%PU,15wt%SM6621,10wt%TMPTAand10wt%TPGDA. The tensile stress was9.2MPa, the tensile strain was29.8%, theadhesion was0, and the pencil hardness was3H. |
