Process for preparing shelf-stable curable polysilazanes, and polysilazanes prepared thereby

A process for preparing curable oligomeric and/or polymeric polysilazanes comprising sequentially

• (a) forming a dichlorosilane-pyridine adduct by reacting dichlorosilane with pyridine, with the proviso that said pyridine is used in an amount that is less than or equal to twice the stoichiometric amount of silicon-halogen bonds in said dichlorosilane;
• (b) combining said dichlorosilane-pyridine adduct and at least one organodichlorosilane;
• and
• (c) carrying out ammonolysis of the resulting combination of said dichlorosilane-pyridine adduct and at least one said organodichlorosilane.

A process for preparing curable oligomeric and/or polymeric polysilazanes comprising sequentially

• (a) forming at least one dihalosilane-base adduct by reacting at least one dihalosilane with at least one base;
• (b) combining at least one said dihalosilane-base adduct and at least one organodihalosilane;
• and
• (c) carrying out ammonolysis of the resulting combination of at least one said dihalosilane-base adduct and at least one said organodihalosilane;
• with the proviso that said base (1) is used for said dihalosilane-base adduct formation in a limited amount that is less than or equal to twice the stoichiometric amount of silicon-halogen bonds in said dihalosilane or (2) is used for said dihalosilane-base adduct formation in excess of said limited amount and, prior to said ammonolysis, the total amount of the resulting reacted and unreacted base is reduced to no more than said limited amount.