Suspensiopolümerisatsiooniga

Suspensiopolümerisatsiooniga, known in English as suspension polymerization, is a polymerization technique where monomers are dispersed as small droplets in a continuous phase, typically water. These monomer droplets are suspended by agitation and stabilized by suspending agents. The polymerization reaction occurs within each individual droplet, which acts as a microscopic reactor. This method is widely used for producing polymers in the form of beads or granules.

The process begins with dissolving or dispersing the monomer, initiator, and any other additives in a water-immiscible solvent. This mixture is then vigorously agitated in an aqueous medium containing suspending agents such as polyvinyl alcohol or cellulose derivatives. The suspending agents prevent the monomer droplets from coalescing. The initiator, which can be oil-soluble for bulk polymerization within the droplet or water-soluble for a combination of suspension and emulsion-like polymerization, is activated by heat or other means to initiate the polymerization chain reaction.

Suspension polymerization offers several advantages. It allows for good control over the reaction temperature due to the high heat capacity of the continuous phase (water), preventing runaway reactions. The resulting polymer beads are easily separated from the reaction medium and can often be used directly without further processing. Common polymers produced by this method include polyvinyl chloride (PVC), polystyrene (PS), and polymethyl methacrylate (PMMA). The particle size and distribution of the polymer beads can be controlled by factors such as agitation speed, suspending agent concentration, and the nature of the monomer.