Synthesis And Application Of Auto Leaf Spring Self-phosphating Antirust Acrylic Emulsion

This dissertation focused on the preparation of self-crosslinkingstructure， one component， environmental friendly waterborne antirustcoating based on auto leaf spring self-phosphating antirust acrylic emulsion.The main achievements were as follows:Propose a method of preparation of functional phosphate ester withphosphorus pentoxide and acrylate hydroxyl-ester. When n (ROH): n (P2O5)=2.2:1，esterification temperature of75℃，the esterification time of3.0h，added water5%，hydrolysis temperature of90℃，the hydrolysis time of2.0h，the synthetic transparent viscous products of single ester rate close to71%，single ester yield close to65%. The structure of functional phosphateester was determined through the test of FT-IR.Propose a method of preparation of functional epoxy-acrylic ester withacrylic acid and E-51.When tetrabutyl ammonium bromide2%，the reactiontemperature of105℃，the polymerization retarder for methoxy phenol of0.1%，when the reaction time of3h，acid conversion rate was99.5%.Introduce the phosphate ester monomer and epoxy acrylate monomerinto the copolymerization reaction. The best prescription was determinedthrough testing the performance of adhesion，water resistance，cohesionrate，stability and so on. When the amount of emulsifier，monomers，epoxyacrylate ester for2.6%，4.0%，4.5%of the total respectively，the emulsioncoating adhesion1grade，resistant to salt water for700h. Several testingmethods such as FT-IR，DSC and TEM were adopted to characterize theemulsion. Emulsion particle size and molecular weight distribution weredetermined by particle size analyzer. The transition temperatures at23.5℃could be clearly observed in DSC curve of the resultant emulsion sample.Obvious core-shell structure was shown in TEM images. Waterborne acrylic coatings which had excellent antirust performancewere prepared based on the core-shell acrylic latex. The maximum lastingtime for salt-water resistance test of the coating exceeded60days. Solveauto leaf spring coating’s problems of low utilization rate，not environmentalprotection and poor rust resistance. Reduced the phosphating process thatsubstrate needs.