Hydrolytic Stability of Terephthaloyl Chloride and Isophthaloyl Chloride
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- 作者：William R. Berti ; Barry W. Wolstenholme ; John J. Kozlowski ; Raymond L. Sobocinski ; Robert W. Freerksen
- 刊名：Environmental Science & Technology
- 出版年：2006
- 出版时间：October 15, 2006
- 年：2006
- 卷：40
- 期：20
- 页码：6330 - 6335
- 全文大小：167K
- 年卷期：v.40,no.20(October 15, 2006)
- ISSN：1520-5851
文摘
The phthaloyl chloride isomers, terephthaloyl chloride(TCl) and isophthaloyl chloride (ICl), are high productionvolume chemicals used in polymers to impart flame resistance,chemical resistance, and temperature stability and aswater scavengers. In these studies, we determined thehydrolytic stability of TCl and ICl and their hydrolysis productsin aqueous solutions. Hydrolysis rates for TCl and IClwere initially determined by gas chromatography/flameionization detection in water buffered at pH 4.0, 7.0, and9.0 and 0 
C for up to 30 min. Subsequent studies determinedthe products from TCl and ICl hydrolysis. The parentphthaloyl chlorides (TCl and ICl), their intermediate hydrolysisproducts (designated as the "half-acids"), and theirstable hydrolysis products (terephthalic acid (TPA) andisophthalic acid (IPA)) were determined by high-performanceliquid chromatography. The half-lives (t1/2) of TCl and IClranged from an average of 1.2 to 2.2 min and from 2.2 to4.9 min, respectively, at pH 4-9 and 0 C. The observed first-order rate constants (kobs) ranged from an average of530 to 1100 (× 105 s-1) for TCl and 240 to 520 (× 105 s-1)for ICl. Both phthaloyl chlorides formed their respective short-lived intermediates, in which one of the two carboxylicacid chloride functionalities reacts with water to form thecarboxylic acid ("half-acid"). Subsequently, the half-acids underwent further hydrolysis so that greater than90% of the initial phthaloyl chloride hydrolyzed in less than60 min at 0 C. The hydrolysis products TPA and IPAwere hydrolytically stable, undergoing no further transformations after 20 min at pH 7 and 25 C. This work demonstratedthat TCl, ICl, and their respective half-acids will not bepersistent in aqueous systems for a time sufficient to havea sustained toxicological effect on aquatic organisms(less than 1 h). Performing additional aquatic toxicity studies,biodegradation studies, and potentially mammalian studies on TCl and ICl are unnecessary since the existinginformation on TPA and IPA with the hydrolysis data presentedhere is sufficient to address questions on the fate andeffects of these two substances in aqueous environments.
C for up to 30 min. Subsequent studies determinedthe products from TCl and ICl hydrolysis. The parentphthaloyl chlorides (TCl and ICl), their intermediate hydrolysisproducts (designated as the "half-acids"), and theirstable hydrolysis products (terephthalic acid (TPA) andisophthalic acid (IPA)) were determined by high-performanceliquid chromatography. The half-lives (t1/2) of TCl and IClranged from an average of 1.2 to 2.2 min and from 2.2 to4.9 min, respectively, at pH 4-9 and 0 C. The observed first-order rate constants (kobs) ranged from an average of530 to 1100 (× 105 s-1) for TCl and 240 to 520 (× 105 s-1)for ICl. Both phthaloyl chlorides formed their respective short-lived intermediates, in which one of the two carboxylicacid chloride functionalities reacts with water to form thecarboxylic acid ("half-acid"). Subsequently, the half-acids underwent further hydrolysis so that greater than90% of the initial phthaloyl chloride hydrolyzed in less than60 min at 0 C. The hydrolysis products TPA and IPAwere hydrolytically stable, undergoing no further transformations after 20 min at pH 7 and 25 C. This work demonstratedthat TCl, ICl, and their respective half-acids will not bepersistent in aqueous systems for a time sufficient to havea sustained toxicological effect on aquatic organisms(less than 1 h). Performing additional aquatic toxicity studies,biodegradation studies, and potentially mammalian studies on TCl and ICl are unnecessary since the existinginformation on TPA and IPA with the hydrolysis data presentedhere is sufficient to address questions on the fate andeffects of these two substances in aqueous environments.