Yu Ong Yong, Chung Jae Woo, Kwak Seung-Yeop
Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744, Korea.
Environ Sci Technol. 2008 Oct 1;42(19):7522-7. doi: 10.1021/es800895x.
The migration of endocrine-disrupting di-(2-ethylhexyl) phthalate (DEHP) poses a serious threat to public health and the environment. In this study, we successfully prepared a plasticizerwith reduced DEHP migration by directly incorporating 2,3,6-per-O-benzoyl-beta-cyclodextrin (Bz-beta-CD) into DEHP. Bz-beta-CD was prepared by esterification between the hydroxyl groups of beta-CD and benzoyl chloride. The presence of this cyclodextrin is expected to facilitate formation of stable complexes through pi-pi association with DEHP molecules. The flexible PVC was prepared with a gelation-fusion process that uses the prepared migration-resistant plasticizer, and its properties (flexibility, thermal stability, and clarity) were evaluated by carrying out DSC and tensile testing, TGA, and haze testing, respectively. No significant changes in the physical properties of the flexible PVC were observed when Bz-beta-CD was added. DEHP migration tests were carried out for the flexible PVC according to the ISO 3826:1993(E) test method, and the quantity of migrated DEHP was then determined with UV-vis spectroscopy. It was found that the addition of Bz-beta-CD decreases the levels of DEHP migration from the flexible PVC samples by almost 40%. We investigated the molecular interaction between Bz-beta-CD and DEHP using molecular mechanics simulations, and we conclude that this reduction in DEHP migration is due to the formation of stabilized pi-pi attractive association and inclusion complexes of Bz-beta-CD and DEHP in flexible PVC.
内分泌干扰物邻苯二甲酸二（2-乙基己基）酯（DEHP）的迁移对公众健康和环境构成了严重威胁。在本研究中，我们通过将2,3,6-全-O-苯甲酰基-β-环糊精（Bz-β-CD）直接掺入DEHP中，成功制备了一种DEHP迁移量降低的增塑剂。Bz-β-CD是通过β-环糊精的羟基与苯甲酰氯之间的酯化反应制备的。预计这种环糊精的存在将通过与DEHP分子形成π-π缔合来促进稳定配合物的形成。使用制备的抗迁移增塑剂，通过凝胶化-融合工艺制备了软质聚氯乙烯，并分别通过差示扫描量热法（DSC）和拉伸试验、热重分析（TGA）和雾度测试对其性能（柔韧性、热稳定性和透明度）进行了评估。添加Bz-β-CD后，软质聚氯乙烯的物理性能未观察到显著变化。根据ISO 3826:1993(E)测试方法对软质聚氯乙烯进行了DEHP迁移试验，然后用紫外-可见光谱法测定了迁移的DEHP量。结果发现，添加Bz-β-CD可使软质聚氯乙烯样品中DEHP的迁移水平降低近40%。我们使用分子力学模拟研究了Bz-β-CD与DEHP之间的分子相互作用，得出结论：DEHP迁移的减少是由于在软质聚氯乙烯中形成了稳定的π-π吸引缔合以及Bz-β-CD与DEHP的包合物。
