Polystyrenes manufacturing processes

Polystyrene is unusual among commodity polymers in that we can prepare it in a variety of forms by a diversity of polymerization methods in several types of reaction vessel. j Polystyrene may be atactic, isotactic, or syndiotactic. Polymerization methods include free radical, cationic, anionic, and coordination catalysis. Manufacturing processes include bulk, solution, suspension, and emulsion polymerization. We manufacture random copolymers ... 

Iodobeads (Thermo Fisher) is an immobilized preparation of a chloramine-T analog, consisting of nonporous, polystyrene beads of diameter 1/8" that have been derivatized to contain N-chlorobenzenesulfonamide groups (as the sodium salt) (refer to US patents 4,448,764 and 4,436,718). During the manufacturing process, the hydrophobic nature of the polystyrene is changed to a rather hydrophilic surface due to the chlorosulfonamide modifications. The surface... 

Manufacturing Processes. By 1945 three processes were competing with each other for the further expansion of polystyrene capacities ... 

Commercial polystyrene manufacturing techniques are based either on a suspension process if the material is to be foamed or on a bulk polymerization process for GPPS and IPS. ABS-type polymers can also be produced via emulsion polymerization. Figure 2.5 shows the differences in emulsion and mass polymerization processes and the resulting morphology. Typically,... 

The commercial manufacture of polystyrene was batch mode through the 1930s and 1940s, with a gradual transition to continuous bulk polymerization beginning in the 1950s. Suspension polymerization was a common early polystyrene production process, where a single reactor produced a polymer slurry that had to be separated from the water and dried. This process was ideal for free radical... 

SAXSAVAXS/RAMAN is especially useful when dealing with chemically induced phase transitions. The example shown in Figure 2(e) is the polymerisation of solvent styrene into polystyrene in which polyethylene is in solution. Polyethylene is soluble in styrene but insoluble in polystyrene. RAMAN allows the determination of the reaction kinetics of polystyrene formation and monitors the crystallisation of the polyethylene. The SAXS monitors the liquid-liquid phase separation followed by the liquid-solid phase transition, whilst the WAXS also observes the liquid solid phase by monitoring the appearance of peaks due to the crystallisation of polyethylene. These are very valuable parameters when trying to define any new manufacturing process. ... 

Polystyrene pyrolysis yielded an oil with a high content of styrene monomer (Fig.4). The reaction conditions were optimized to maximize the yield of styrene. A maximum of l6% (by weight) was obtained. The oil is suitable for reuse in the styrene manufacturing process. 

In general, high impact polystyrenes are multiphase systems consisting of a continuous rigid polystyrene phase and discrete rubber particles 0.5-lOjU in diameter. The incorporated rubber particles are crosslinked and contain grafted polystyrene, and their inner structure is determined by the manufacturing process and can vary considerably. The principle polystyrene structures have been described in detail (I, 2). 

---