Polyvinyl- and polyphenylsilsesquioxanes and their films: an investigation by X-ray diffractometry, positron diagnostics, and 29Si NMR spectroscopy

Polyvinyl- and polyphenylsilsesquioxanes (RSiO 1,5 ) n were synthesized by hydrolytic polycondensation. The cross section surface areas of the polymer chain were measured and the sizes of “traps” of the free and ordered volumes and the ratio of the T 2 and T 3 units in (RSiO 1,5 ) n were determined by time positron diagnostics, 29 Si NMR spectroscopy, and X-ray diffractometry. The density of polyvinyl- and polyphenylsilsesquioxanes was determined picnometrically and from the X-ray phase analysis data, and the content of hydroxyl groups was found by thermogravimetry. The cross section surface area of the silsesquioxane chains containing vinyl and phenyl radicals at Si were calculated by the Miller-Boyer method. The elementary volumes of the chain segments determined by different methods were compared. The geometric models for “traps” of the free volume were proposed. The optical properties and morphology of the polyvinylsilsesquioxane films were studied by atomic force microscopy and UV spectroscopy.