Abstract: A process for preparing polymers and copolymers based on vinyl chloride by mass polymerization of a monomer composition based on vinyl chloride, comprising carrying out at least part of the polymerization reaction in a polymerization zone defined by an essentially spherical wall by effecting in the said polymerization zone a controlled and regulated circulation of the polymerization reaction mixture by means of a rotated blade-type turbine assembly, where the said blades pass by in the vicinity of the said wall over 10% to 60% of its surface, the reaction mixture being caused by the centrifugal force of said rotated blade-type turbine assembly to perform an at least partially ascending movement over at least part of the spherical wall and falling back, essentially under the action of gravity in the central part of the spherical polymerization zone, thus ensuring intensive mixing without dead space.

Abstract: A process for preparing polymers and copolymers based on vinyl chloride by mass polymerization of a monomer composition based on vinyl chloride, comprising carrying out at least part of the polymerization reaction in a polymerization zone defined by an essentially spherical wall by effecting in the said polymerization zone a controlled and regulated circulation of the polymerization reaction mixture by means of a rotated blade-type turbine assembly, where the said blades pass by in the vicinity of the said wall over 10% to 60% of its surface, the reaction mixture being caused by the centrifugal force of said rotated blade-type turbine assembly to perform an at least partially ascending movement over at least part of the spherical wall and falling back, essentially under the action of gravity in the central part of the spherical polymerization zone, thus ensuring intensive mixing without dead space.

Abstract: The bulk polymerization of monomers which produce polymer insoluble in the monomers, in which the polymerization is carried out in an autoclave mounted on a horizontal axis and provided with stirring means formed of at least two half-frames arranged symmetrically of the axis of the autoclave and fixed at each end to a rotatable stub shaft axially mounted in the autoclave, each half-frame having a peripheral member serving as a blade which, on rotation of the half-frames, passes in close proximity to the interior surface of the autoclave, and bracing means interconnecting the peripheral members of the half-frames.