suspensiopolymerointimenetelmillä

Suspension polymerointimenetelmät, often referred to as suspension polymerization, is a free-radical polymerization process. In this method, monomers are dispersed as droplets in a continuous phase, typically water, which acts as a heat sink and prevents aggregation. The polymerization is initiated within these monomer droplets, which are stabilized by suspending agents such as polyvinyl alcohol or cellulose derivatives.

The process involves dispersing the water-insoluble monomer, along with an oil-soluble initiator, into an aqueous medium containing suspending agents. Vigorous agitation is maintained to ensure the formation of small, uniform droplets and to prevent them from coalescing. The suspending agents adsorb onto the surface of the monomer droplets, providing steric or electrostatic stabilization. Heat is supplied to initiate the polymerization reaction, which proceeds within each individual droplet.

Upon completion, the result is polymer beads or particles suspended in the aqueous phase. These beads are typically spherical and can range in size from microns to millimeters, depending on the polymerization conditions and the choice of suspending agent. The continuous aqueous phase is then separated, and the polymer beads are washed and dried. Suspension polymerization is widely used for the production of various polymers, including polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA), and is favored for its ability to control particle size and morphology, as well as its effective heat removal.