Suspension polymerization of unsaturated polyester oligomers

Abstract

A study has been made of an unsaturated polyester resin prepared from maleic anhydride, phthalic anhydride and 1,a-propene glycol. The resin is transformed by alkalization with ammonia into a water-soluble emulsion, which was polymerized with initiators and accelerators. It was found that water acts as an inert diluent in the emulsion. By measuring the temperature of the reaction mass during polymerization, the actual conversion has been estimated. The latter is lower than literature values. A correction of the method of A. Rojas et a1 for the determination of the actual conversion is proposed, and the polymerization heat is thus determined. A value of 478 J/g is obtained, which is higher than reported. The apparent order of the polymerization reaction has also been determined: it changes from 5 to 18 with reaction progress.

Suspension copolymerization of unsaturated resins with styrene and acrylonitrile

“…At higher water content in the emulsion the reaction heat is less. Similar effect was observed on diluting the resin with solvents 5) .…”

On the use of extruders as chemical reactors

“…Binary polymer blends containing a single crystallizable component have become a subject of our investigations. In a previous study, we established that during the extrusion of PA‐6 and PBAN‐40 the nitrile groups in the elastomer undergo chemical changes 12. It is an interesting fact giving rise to the application of the reactive extrusion for compatibilization of the system without grafting of new reactive groups onto the elastomer chains or introduction of a compatibilizer.…”