Modifications of preceramic polymers suitable for corrosion resistant and high temperature coatings

Low-cost preceramic polymers have been developed and used for various coating and composite applications. These siloxane-based polymers can be tailored to be precursors to ceramics or remain as polymeric materials. Polyhydridomethylsiloxane (PHMS) serves as the base polymer, and it can be cured or modified by dehydrocoupling or a combination of hydrosilylation-dehydrocoupling reactions, both catalyzed by transition metal catalysts (Pt and Ru). The base polymer filled with various powders is used primarily for thick ceramic coatings. Modified polymers are used for low-temperature paint-like applications, especially where ambient curing is desirable. Both organic and inorganic modifications of PHMS for coating applications are discussed in this article. Paints containing such polymers and fillers are being evaluated for corrosion resistance and high-temperature applications.