Effects of water vapor on poly(vinyl butyral) ceramic binder burnout

摘要

The effects of water vapor on non-oxidative poly(vinyl butyral) functional group decomposition mechanisms are described. Species-specific evolution profiles obtained by mass spectrometric analysis of gases evolved while heating silica, mullite, and 250L?alumina coated with poly(vinyl butyral) binder show that volatile product yields are affected by the presence of water vapor. When water vapor is incorporated into binder burnout atmospheres, acetic acid yields increase and C_(4)H_(6)O yields decrease. Acetic acid yields increased because water vapor interacted with oxide basic sites that otherwise reacted with acetic acid to form carboxylate species. Water vapor also inhibits C_(4)H_(6)O formation, possibly by stabilizing a polar intermediate produced during side group cleavage reactions.