ZIRCONOCENE-MODIFIED POLYSILOXANE-2-PYRIDINE COATINGS

Pyridine-pendent siloxane polymers containing a backbone modified with a zirconocene moiety were synthesized through the hydrolysis-condensa tion reaction of the mixed precursor solutions of the beta-trimethoxys ilylethyl-2-pyridine sol in liquor medium and the zirconocene dichlori de (Cp(2)ZrCl(2)) dissolved in tetrahydrofurane. This polymer, in term s of the polyzirconocenesiloxane-2-pyridine (PZSP), was then evaluated for use as thin coating films (thickness, 0.5-1.0 mu m), which provid es excellent protection of aluminum (A1) alloys against NaCl-caused co rrosion. The PZSP films deposited by simple dip-withdrawing coating me thods to A1 displayed the impedance of > 10(6) Omega cm(2) after expos ure for 40 days in 0.5 N NaCl solution at 15 degrees C and 3000 h salt -spray resistance.