Abstract: Relationships between structures of a series of silazane compounds and their hydrolytic stability were investigated by contacting silazane compounds directly with water vapor. It was indicated that steric hindrance of substituents strongly influenced hydrolytic stability of silazane compounds. Compounds with bigger substituents had better hydrolytic stability. As for cyclosilazanes, hydrolytic stability was also dependent on ring strength. However, steric hindrance played more dominant roles. Cyclosilazanes with phenyl substituents, hexaphenylcyclotrisilazane and polymeric compounds containing Si-N bond were of excellent hydrolytic stability due to high steric hindrance.

Key words: Silazane compound, Hydrolytic stability, Steric hindrance, Ring strength