Preparation of large-particle-size monodisperse latexes in space - Polymerization kinetics and process development

Monodisperse polystyrene latexes are prepared by seeded emulsion polymerization; however, sizes larger than 2 microns are difficult to prepare because of the creaming and settling of the particles and their sensitivity to mechanical shear. Preparation in space would obviate the creaming and settling, and allow agitation just sufficient for good heat transfer and mixing. Three polymerizations yielding 3-5 micron size particles were carried out successfully on the third flight of the 'Columbia' launched Mar. 22, 1982; however, four polymerizations yielding sizes up to 10 microns on the fourth flight launched June 27, 1982 were incomplete owing to apparatus malfunction. The results of these polymerizations and the prospects of developing a preparative space process are reviewed.