Abstract: In a suspension polymerization process of preparing styrenic polymer particles from a styrenic monomer and small particles of a styrenic polymer in a definite particle size range, styrenic polymer particles having a uniform particle size are obtained without the formation of fine polymer powders by simultaneously but separately dropwise adding to an aqueous suspension of the small particles of the styrenic polymer (1) a solution of 100 - 60% by weight of a suspension polymerization catalyst and 1 - 10% by weight of the styrenic monomer and (2) a solution of 0 - 40% by weight of the catalyst and 99 - 90% by weight of the styrenic monomer simultaneously but separately from each other.

Abstract: Process for the production of latices of conjugated diene polymers and conjugated diene copolymers with vinyl compounds by emulsion polymerization comprising(a) a first polymerization stage in the presence of the monomer as a phase separate from the polymer being formed,(b) an intermediate stage in which the monomer is added in quantities such that the conversion of the monomer at the end of each individual addition exceeds 45%, and(c) a final stage in which the reaction is carried to completion.

Abstract: An improved process for producing powdery water-soluble vinyl high-polymers by reversed-phase emulsion polymerization. The vinyl monomer is polymerized in the form of W/O type emulsion dispersed as an aqueous solution in a non-polar organic solvent immiscible with water and having a boiling point in the polymerization temperature range of the vinyl monomer, under stationary evaporation and reflux of part of the solvent, whereby the oxygen in the polymerization system is completely removed and thus the polymerization is enhanced to achieve an extremely high polymerization degree.

Abstract: A vinyl acetate copolymerizate of monomers being a free-radical polymerized copolymerizate having monomer units consisting essentially ofA. from 60% to 80% by weight of vinyl acetate units,B. from 10% to 20% by weight of units of a maleic acid diester with a straight-chained alkanol-1 having from about 8 to 10 carbon atoms,C. from 5% to 20% by weight of units of a mono-olefinically unsaturated ester having from 6 to 8 carbon atoms and a hydrophilic group, andD. from 3% to 10%, particularly 7%, by weight of crotonic acid; as well as an alcoholic solution thereof and salts thereof.

Abstract: Particle morphology and molecular weight distribution of latex polymers is controlled by a process wherein a primary polymerizable feed composition, (a) a crosslinker and (b) a chain transfer agent during at least a portion of the period of addition of said composition to the polymerization zone, is fed into a polymerization zone while simultaneously feeding a secondary polymerizable feed composition containing chain transfer agent to the primary polymerizable feed composition and thus continually varying the compositional content of the primary polymerizable feed composition.

Abstract: Initial depletion of organosulfur molecular weight regulator during initial polymerization conversion in emulsion polymerization systems employing coagitated mixtures of emulsifiers and organosulfur molecular weight regulators is reduced by coagitating in the presence of an additive which is monomer-soluble diluent a portion of polymerizable monomer prior to use of the coagitated admixture in the emulsion polymerization systems.

Abstract: A non-continuous suspension polymerization process for the production of finely-divided, low molecular weight polymeric particles of an aryl monomer is carried out in a heated aqueous suspension media at a polymerization temperature above the glass transition temperature of the desired polymer. The monomer reactants and the polymerization initiator are substantially simultaneously introduced into the heated suspension media at a slow, substantially continuous rate over a time within the range of from 20 to about 85 percent of the total polymerization reaction time. The suspension media is subjected to high-rate shearing throughout the reaction.

Abstract: Vinyl halide is homopolymerized under suspension conditions with additional vinyl halide being added after the pressure drop with polymer being recovered only after the polymerisation is completed.