Study Of Environmental Friendly Nano-composite Coating Containing Fluorine

In this paper,a kind of environmental friendly nano-composite coating which can be used for high performance exterior wall coating is studied.The paper mainly includes the contents as follows.The first is the preparation of nanoscale pigment.Nanoscale titanium dioxide powder is prepared in terms of sol-gel process with TI(OC4H9) as raw material.The experiment results show that the productivity of nanoscale titanium dioxide is the highest when PH value of the hydrolysis system is about 2.5.TEM photoes show that the products'sizes are between 50-100nm.XRD tests indicate the crystal style of the products is rutile type.In order to apply nanoscale titanium dioxide to coating as pigment,it must be modified.The nanoscale particles are modified in terms of esterifying reaction.silane coupling agent and organic titanate coupling agent.The activation index and contact angle test results of the products prove the sequence of hydrophobic modification effect: organic titanate coupling agent modification) silane coupling agent modification esterifying reaction modification.The second is the synthesis of emulsion containing fluorine.A kind of acrylate copolymer emulsion containing fluorine is prepared.with hexafluorobutyl mathacrylate, hexafluorobutyl acrylic acid,butyl acrylate.methyl methylacrylate as ingredients.The experiments indicate that the best coplymerization reaction conditions are 88℃ and 2 hours.Among several kinds of emulsifiers.the experiment results prove that the composite emulsifier of MS-l,SDS,FC-10 is the best and it's best amount is 5%.The orthogonality experiment results show that the amount of functional monomer has a remarkable influence on gel amount and the amount of monomer containing fluorine has deep influence on products'surface tension and water adsorption.The DSC test results indicate that emulsion products'Tg is about 26 ℃,this temperature is close to its'MFT test results.The third is the development of environmental friendly nano-composite coating containing fluorine.The coating is developed with modified nanoscale titanium dioxide, emulsion containing fluorine and additives as materials.Thecoating's formulation is determined in terms of experiments. The performance test results of the coating indicate that it's performances are up to the national standard of synthetic resin emulsion coatings for exterior wall.The coating's performances are superior to aery late emulsion coating for exterior wall.The hiding power of the coating is the best when the amount of nanoscale pigment is 25%.A formula is deduced to calculate pigment's CPVC,according to the formula,we calculate that the CPVC of nanoscale titanium dioxide powder is 0.42.