苯胺與TMOS 或TEOS 對SAE 1018 的抗腐蝕研究

Abstract

In this research, aniline, TMOS (or TEOS) and PMMA were used to prepare an organic-inorganic composite anticorrosive film on the SAE 1018 steel plate. Aniline acts as an inhibitor to lower the corrosion rate of the iron. PMMA plays a film forming role. Film thickness is linearly dependent on the amount of PMMA. TMOS (or TEOS) fills into the pores of PMMA that increases the film hardness and adhesion to the iron surface. Determining the amount of Si(OH)4 producing after mixing aniline and TMOS (or TEOS) for 4 d, the amount of the former being hydrolyzed is 4.83% and the latter is only 0.20%. Mixing 82.5 w%, 12.5 % and 5.0 % of aniline, TMOS and PMMA, respectively, using dip coating method to form a film on the iron plate and then drying it under 135°C for 30 min. The film formed has an adhesion test of 0% area off with a hardness of 9 H. Corrosion potential of the film is 0.185 V higher than that of the bare iron. Corrosion current density, corrosion resistance and annual corrosion rate is 2.1 (2) μA/cm2, 3.11 k$·cm2 and 0.021 mm/y, respectively. Salt spray test is 2540 (48) h while 15% area is corroded. Mixing 82.5%, 12.5% and 5.0% of aniline, TEOS and PMMA,respectively, reaction for 12 d, adhesion test result is < 5% area off and salt spray test is 1156 (36) h. Obviously, the film prepared by TMOS has a better protective effect to the iron plate. TMOS has a shorter carbon chain than TEOS. Volume of TMOS molecule is smaller than that of TEOS. It is more favorable for the former to fill into the pores in PMMA. Increasing the degree of hydrolysis in TMOS might increase the adhesion between Si(OH)4 and Fe atom. As a result, increasing the adhesion between the film and the iron plate increases the protection of the steel surface.