Discoloration of Tetrabromophthalic Anhydride Polyseter Resins

Use of Tetrabromophthalic Anhydride (TBPA) in the Construction of Fire-Retardant Polyester and Epoxy Resins

“…While the effect of the Br atoms must be considered paramount, the possible contribution of the terminal tetrabromophenylcarboxy groups should not be overlooked in view of the decarboxylation reaction shown to take place at temperatures above 185°C. Further evidence for the fire-retardant contribution from this source rests upon the fact that when the -COOH group is masked by reaction with an oxirane compound-e.g., octylene oxide or glycidyl methacrylate-the modified resin loses a part of its fire-resisting capability (Spatz et al, 1969). This evidence is slightly clouded by the fact that the bromine content in the modified resin is more dilute.…”

“…Very little work was done to extend the catalytic procedure to polyester synthesis. ^he value of tetrabromophthalic anhydride (TBPA) in the construction of fire-retardant polyester and epoxy resins has been disclosed Nulph, 1965, 1966;Spatz and Koral, 1966;Spatz et al, 1969). Unfortunately, the use of TBPA in this type of application is confronted with difficulties.…”

“…The need for quality TBPA and the slow esterification rate of the second carboxy group have 1 Present address, Tenneco Manufacturing Co., Flemington, N. J. 2 Present address, Crompton & Knowles, Reading, Pa. 3 Present address, American Can Co., New York, N. Y. been noted (Spatz et al, 1969). While for all practical purposes the quality problem can be circumvented either by purification (Spatz and Koral, 1966;Spatz et al, 1969) or by the addition of alkaline-type chemicals to commercial TBPA Nulph, 1965, 1966), the slow esterification in noncatalyzed, melt-type polyesterifications leaves much to be desired.…”

“…The authors have shown (Spatz et al, 1969) that TBPA can be monoesterified rapidly, and that it can be diesterified, as an indication of polyesterification capability, at ca. 185°C.…”