Polarographic Determination of Maleate Unsaturation in Polyesters

Ultraviolet Spectrophotometric Determination of Styrene and Phthalate and Fumarate Esters in Polyester Resins

“…Typical polyester resin formulations of known composition were prepared by the polyester resins group of these laboratories. The exact styrene content was checked by distilling out the styrene from a butoxyethyldiglycol carbonate solution of the polyester formulation; the styrene content of this distillate was determined by the one-component ultraviolet spectrophotometric method of McGovern and coworkers (5).…”

“…For convenience, the dibasic acid was assumed to have lost two atoms of hydrogen during esterification, hence FWP = 164.11 and FWf = 114.05; the propylene glycol is assumed to have lost two hydroxyl groups, hence FW, = 42.05. With no other components present, we also have the relation that Cm + Cp + C; + Cg = 100% (5) Combining these equations, Cm + C"(l + FWg/FW p) + Cf{ 1 + FWg/FWf) = 100% (6) T h i s c o n t e n t i s (…”

“…Such a method can be of value in the checking against established specifications by such consumers as the various government agencies. The successful application of ultraviolet spectrophotometric methods to related problems, such as the determination of phthalic acid in alkyd resins (9), monomeric styrene in polystyrene (5,7), and polymerized styrene in styrenated fatty acids (/), suggested the applicability of this technique to the polyester resin formulations. Here the two major absorbers are usually the phthalate component of the polyester and monomeric styrene, with a minor contribution from the fumarate or maleate component.…”

Review - Coatings

“…Hobart (10) has developed a method for unsaturated acids in polyesters which is fast and flexible, and which, under suitable conditions, might be applied to the usual coating-type resins. Using polarography, Hobart determined maleic and/or fumaric acids directly on the polyester-monomer formulation as received.…”

“…Phthalic can be determined on the dipotassium salt by the Shreve (26) method. It has been shown (10) that maleic acid can also be determined on the Kappelmeier salt by polarographv and, in the simpler case of unsaturated polyester resin formations, in situ. In addition, the authors prefer identification of the dibasic acids present, using the benzylamine procedure (29), prior to any quantitative work.…”