Redox polymerization of unsaturated polyester resins. II. Effect of copromoter metals on the redox polymerization activity of vanadium chelates

Abstract

synopsisOf a series of copromoter metal species investigated, it waa found that several of these were strongly effective in synergizing the redox polymerization activity of vanadyl acetyl acetonate. Notable among these were Cu+2, Fe+3, Ti+3--Ti+6, Be+2, Alf3, and Th+4. Particularly notable was the effect of Ti +3-Ti +6, which strongly synergized the rate a t which complete polymerization was obtained, eg., within 15 min. as compared to 20 hr. when vanadyl acetyl acetonate was used alone. Synergism with copromoter metal species was noted with as low as 2 mg. titanium used in conjunction with 2 mg. of vanadyl ion as the chelate. A minimal concentration for synergistic effect was noted for those metal species thus studied. This was found to range from 0.18 to 0.41 mmole of copromoter metal species per 100 g. of resin system. Advantage was taken of the peculiar effect of manganic acetyl acetonate to prolong gel times without affecting the rate at which complete polymerization was obtained. By using manganic acetyl acetonate in conjunction with vanadyl acetyl acetonate, it was possible to prolong the shelf-life of a prepromoted resin from 17 to at least 110 days.