| Abstract: | Heating N,N′-diphenyltetramethylcyclodisilazane with phenylenediamines in the melt at temperatures over 200°C was found to yield oligomers composed of linear and cyclic disilazane units interlinked by phenylene groups. Increasing the temperature of the reaction of meta- and particularly para-phenylenediamine over 300°C promotes formation of crosslinked, infusible, and insoluble polymeric material. The succeeding steps of growth of the polymer molecules, which include cyclodisilazane ring cleavage, transaminations, and recyclizations, have been studied by elemental and spectroscopic analyses of the intermediate low molecular and oligomeric species in the distillable and nonvolatile products of the reactions. |
