Preparation Of Modified Polymer By Nano-titanium And Its Application In Coatings

Metal titanium is a kind of material which is known for its good corrosion resistance.However,the metal titanium is expensive.If the polymer coatings which were applied in the anti-corrosion fields of metal structures can replace stainless steels which were prepared by the grafting of nano-titanium and organic polymer,the problem of corrosion would be solved.Furthermore,it can reduce the economic loss greatly and improve enterprise's economic efficiency.In this experiment,modified polymer by nano-titanium was prepared by adopting chemical method,physical-chemical bonding method.The SEM test of modified polymer by nano-titanium showed that the titanium powder prepared by chemical method was easy to agglomerate.The coupling agent,titanium powder with resin had few or no grafting.If applied it to the coating will seriously affect the performance of the coating and fail to achieve expected results.When modified polymer by nano-titanium was prepared by physical-chemical bonding method,titanium powders were high-speed grinding by high-energy ball mill.Then titanium powders were dispersed into irregular sheet structure.Meanwhile,the specific surface area increased and the lattice defects happened.In this case,titanium powders can easily modify and graft by resin.The dispersion of modified polymer by nano-titanium became better.Modified polymer by nano-titanium was prepared by the physical-chemical bonding method.The milling speed,milling time,the amount of KH560 and the ratio of ball were studied by single factor test method.The sedimentation height method and mass method were used to analyze modified polymer by nano-titanium.The best grinding condition was determined and the target product was characterized.Modified polymer by nano-titanium coating which based on tinplate was prepared by orthogonal test method.The prepared coating was tested for its the mechanical properties,the electrochemical test and salt spray resistance test of coating were analyzed for determining the best formula of modified polymer by nano-titanium coatings.Coatings based on all the solid samples after centrifugation and the sample 3(the upper samples of all the solid samples)were prepared respectively.The properties and anti-corrosive mechanism of coatings were discussed.When the modified polymer by nano-titanium was prepared by physical-chemical bonding method,the dispersibility of titanium powder in polymer was getting better with the increase of ball milling speed and milling time.In addition,the stability of modified polymer by nano-titanium became better correspondingly.However,the instrument would damage when the ball mill was applied at a high speed for a long period.So the ball milling speed was set at 700 r/min and the milling time was set as 4 h.With the increase of KH560 usage and the ratio of ball to material,the dispersibility of titanium powder in polymer was getting better and approximately trends to be stable when the amount of KH560 accounts for 1 % of titanium powder and the ratio reaches 4:1.Therefore,the dispersibility of modified polymer by nano-titanium is the best when the ball milling speed is 700 r/min,time is 4 h,the amount of KH560 accounts is 1 % of titanium powder and the ball to material ratio is 4:1.The results of FT-IR test showed that the absorption peak of Si-O-Ti existed in modified polymer by nano-titanium which prepared by physical-chemical bonding method.It indicated that KH560 was grafted onto the surface of titanium powder.The samples which prepared by the physical-chemical bonding method were centrifuged and found to be stratified at the bottom of the centrifuge tube.The TG test and XRD test showed that there were unmodified completely titanium powders in the samples which prepared by the physical-chemical bonding method after centrifugation,most of unmodified titanium powders settling to the bottom of the centrifuge tube.Based on the tinplate,the best experimental formula for the modified polymer by nano-titanium coating was determined by orthogonal test: the modified polymer by nano-titanium accounting is 8%,the defoamer is 0.1%,the leveling agent is 0.2%,the wetting and dispersing agent is 0.5%.The mechanical properties of modified polymer by nano-titanium coatings were tested as follows: impact resistance was not less than 50kg·cm,adhesion grade was 1,extends of flexibility was 1 mm.Coatings based on all the solid samples after centrifugation and the sample 3(the upper samples of all the solid samples)were prepared respectively.Electrochemical impedance test showed that the resistance value of the coating which prepared by all the solid samples tends to stabilize at the value of 1.03 × 108 ?·cm2 after soaking in 3.5% NaCl solution for 25 days.But the resistance value of the coating which prepared by sample 3 tends to stabilize at the value of 2.5×108 ?·cm2 after soaking in 3.5% NaCl solution for 28 days.The anti-corrosive effect of coating which prepared by sample 3 was better.Tafel polarization curve test showed that the corrosion current of the coating which prepared by the sample 3 was 1.905×10-9 A and the corrosion potential was-0.147 V.But the corrosion current of the coating which prepared by all the solid samples after centrifugation was 1.778 × 10-8 A and the corrosion potential was-0.172 V.The anti-corrosive effect of coating which prepared by sample 3 is better than the coating which prepared by all the solid samples prepared after centrifugal.This is mainly because unmodified titanium powder affects the coating's corrosion resistance.The salt spray test showed that the coating's corrosion resistance of prepared by sample 3 which based on the best experimental formula was the best.