A self-assembly composite synthesis technology was used to put together a Ce(OH)(sub 3)-dispersed poly-acetamide-acetoxyl methyl-propylsiloxane (PAAMPA) organometallic polymer. Three spontaneous reactions were involved; condensation, amidation, and acetoxylation, between the Ce acetate and aminopropylsilane triol (APST) at 150 degrees C. An increase in temperature to 200 degrees C led to the in-situ phase transformation of Ce(OH)(sub 3) into Ce(sub 2)O(sub 3) in the PAAMPA matrix. A further increase to 250 degrees C caused oxidative degradation of the PAAMPA, thereby generating copious fissures in the composite. We assessed the potential of Ce(OH)(sub 3)/ and Ce(sub 2)O(sub 3)/ PAAMPA composite materials as corrosion-preventing coatings for carbon steel and aluminum. The Ce(sub 2)O(sub 3) composite coating displayed better performance in protecting both metals against NaCl-caused corrosion than did the Ce(OH)(sub 3) composite. Using this coating formed at 200 degrees C, we demonstrated that the following four factors played an essential role in further mitigating the corrosion of the metals: First was a minimum susceptibility of coating's surface to moisture; second was an enhanced densification of the coating layer; third was the retardation of the cathodic oxygen reduction reaction at the metal's corrosion sites due to the deposition of Ce(sub 2)O(sub 3) as a passive film over the metal's surface; and, fourth was its good adherence to metals.
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