2001 Volume 58 Issue 9 Pages 453-461
In the tetrabromobisphenol A-bis (2, 3-dibromopropyl ether) (TBA-DB) and polypropylenes (PP) system, the blooming was suppressed by the addition of ethylene/vinyl acetate copolymer (EVA) to PP, and the relation between the EVA content necessary for the suppression of blooming and the TBA-DB content was determined. The appropriate temperature of blooming acceleration test for injection molding was not generally high but moderate around 50°C. A general acceleration test could be applied to the phenomenon where the reaction rate obeys the Arrhenius equation and was accelerated by elevating temperature. In the case of injection moldings a similar behavior to that of a solution where a solute dissolves in a solvent was observed in their blooming phenomenon. Namely, at high temperatures, the solubility is high and the precipitating (blooming) material is scarce (or absent). On the other hand, at low temperatures, although the precipitating material is abundant, the transportation rate is low and hence the blooming does not occur. The most appropriate temperature was determined to be around 50°C on a balance of the above-mentioned compensating effects.
