Preparation of Epoxide Group Containing Silicone Resin Coating Cured with Phosphated Polyaniline and Its Properties

To improve the curing condition of the silicone resin and the corrosion resistance of the coatings, silicone resin containing epoxide group (ESiR) was synthesized by sol-gel method with gamma-glycidoxypropyl trime thoxy silane (GPTMS), tetraethoxy silicate (TEOS), and dimethyl diethoxy silane (DMDMS) as silane monomer. The silicone resin anticorrosion coatings were then prepared by using phosphated polyaniline (PANI) as curing agent. The curing reaction of PANI cured silicone resin containing epoxide group was analyzed. The effect of PANI amount on curing degree of the coatings was investigated by the curing time, flexibility, hardness and thermo gravimetric curve. The effects of PANI amount on the coatings properties were investigated by adhesion, contact angle, water absorption, electrochemical impedance spectroscopy (EIS) and potential polarization curve. Results show that the coating has better curing degree, hydrophobicity property, adhesion, and excellent anticorrosion properties when the amount of PANI is 3%. The coating has both good flexibility and high hardness. The water contact angle of the coating is 103.5 degrees and the water absorption rate is 8.91%. The dry adhesion and wet adhesion are grade 0, respectively. The corrosion current density is 7.58 x 10(-8) A/cm(2), and the electrochemical impedance value reaches 3.4x10(6) Omega.cm(2).