The effects of silica, mullite, alpha-alumina, and gamma-alumina on the nonoxidative thermal degradation of poly(butyl methacrylate) are described. Under conditions similar to those employed for nonoxidative ceramic sintering, more volatile alkyl aromatic species were detected when polymer/oxide samples were heated than when the neat polymer was heated. Relative to the neat polymer, all of the inorganic oxides inhibited monomer evolution and promoted an ester decomposition reaction that yielded butene. Infrared analysis indicated that poly(methacrylic acid) segments resulting from ester decomposition reacted to form anhydride. The presence of water vapor during the thermal degradation of the neat polymer and polymer/oxide samples lowered the temperatures at which monomer evolution maximized but had little effect on butene evolution. When the polymer was coated on gamma-alumina, significant amounts of carboxylate were formed above 400 degrees C as a result of deprotonating poly(methacrylic acid) functionalities on the gamma-alumina surface.