水分散型SiO2@PANI防腐材料的制备及性能

Synthesis of Water Dispersive SiO2@PANI Anticorrosion Materials and its Properties

摘要:

用γ-(2, 3-环氧丙氧)丙基三甲氧基硅烷(GPTMS)对SiO2表面进行修饰，再引入苯胺合成聚苯胺(PANI)接枝的SiO2溶胶(SiO2@PANI)，经乙烯基三甲氧基硅烷(VTMS)原位包埋后得到SiO2@PANI/VTMS复合溶胶。讨论了反应温度和引发剂用量对SiO2@PANI的分散稳定性、粒径、复合涂层接触角以及防腐蚀性能的影响，通过红外光谱(FT-IR)、扫描电子显微镜(SEM)等方法表征了SiO2@PANI粒子的结构与形貌。结果表明用GPTMS改性的SiO2有利于苯胺通过氨基与环氧基的反应均匀的在其表面聚合，得到以SiO2为核和PANI为壳的核壳型SiO2@PANI溶胶。SiO2@PANI具有良好的水分散稳定性和导电性，以其制备的SiO2@PANI/VTMS复合溶胶可以直接涂在镁锂合金(Mg-Li)表面形成疏水涂层，涂层水接触角高达135.7°；涂层对Mg-Li合金具有优异的防腐蚀性能，其电化学阻抗值达到2.5×104 Ω•cm2，腐蚀电流密度仅为7.51×10-7 A/cm2。

Abstract:

Polyaniline(PANI) grafting SiO2(SiO2@PANI) sol was synthesized with aniline and SiO2 which modified by (3-glycidoxypropyl)-trimethoxylsilane(GPTMS), and prepared SiO2@PANI/VTMS composite sol after in situ embedding with vinyl trimethoxysilane(VTMS). The effects of reaction temperature and initiator dosage on the dispersion stability, particle size, contact angle and corrosion resistance of SiO2@PANI and coatings were discussed. The structure and morphology of SiO2@PANI were characterize by Fourier transform infrared spectrum(FT-IR), scanning electron microscopy(SEM), and so on. The results showed that it is favorable for aniline to polymerize homogeneously on the surface of SiO2 by the reaction between the amino group and epoxy group, and obtained core-shell type SiO2@PANI sol with SiO2 as core and PANI as shell. The SiO2@PANI sol has good dispersion stability in water and conductivity. The SiO2@PANI/VTMS composite sol prepared by SiO2@PANI could form hydrophobic coatings by coat it on the surface of magnesium-lithium (Mg-Li) alloy directly. The coatings have a high hydrophobic contact angle which reached 135.7°, and have excellent corrosion resistance performance to Mg-Li alloy which the electrochemical impedance value is 2.5×104 Ω•cm2 and the corrosion current density is merely 7.51×10-7 A/cm2.