High-regularity ladder polyhydric sesquisiloxane and its copolymer and preparing method thereof

The present invention relates to a high-regularity trapezoidal polyhydric sesquisiloxane (H-T) and its random or block polymer. It is made up by using trichlorosilane (HSiCl2), and according to the requirements for its silicon-hydrogen radical content, adding a proper quantity of correspondent organic radical trichlorosilane and alpha, omega diamine, and making them implement the processes of preammolysis reaction and hydrolysis reaction at low-temp., and then according to the requirement for its product molecular weight and in the presence of a proper quantity of molecular weight controlling agent (hexamethyl oxydisilane-MM), using concentrated sulfuric acid as catalyst to make them implement the reactions of polycondensation and equilibration. Its reglarity can be up to 90-100%, and molecular weight can be controlled, and its range is 3X10 3-4X10 6, and its Si-H content is 1-100%.