The hydrolytic stability of polyorganosiloxanes containing cyclodisilazane in the backbone and their monomer were studded. The phenyl substitution on silicon was observed to increase the hydrolytic stability of silicon-nitrogen bond in the cyclodisilazane. However

it was found that siloxane segment bonded cyclodisilazane could increae the hydrolytic stabilyty of silicon-nitrogen bond

while the macromolecular structure could give substantial increase in the hydrolytic stability. Hence

the polymers obtained are very stable to water.