Styrene → Styrenemaleic anhydride

Participants

Reaction Steps

U.S. Pat. No. 4,145,375 teaches a process for copolymerizing styrene and maleic anhydride by the steps of gradually mixing maleic anhydride with styrene in a mass stage under polymerizing conditions to form styrene-maleic anhydride polymer and then suspending the styrene-rich mixture in water, the styrene polymerization is completed as in a conventional mass/suspension polymerization system. Following polymerization, polymeric beads are separated from the water and dried. The disclosure indicates that after drying, the beads are likely to contain internal moisture and in addition approximately 15% of the bound maleic anhydride may be present in the acid rather than anhydride form, and, consequently, during extrusion, the acid portion reverts to the anhydride with the elimination of water. The disclosure indicates that a well-vented extruder is needed to produce a bubble-free extrudate.

Provenance & Evidence