SusChEM: Covalent Phthalate Mimics: an Alternative to Phthalate Plasticizers

非技术总结：该奖项将支持加州大学圣克鲁斯分校Rebecca Braslau教授的研究项目，以开发聚氯乙烯（PVC）配方中使用的邻苯二甲酸酯增塑剂的替代品。Braslau教授和她的学生计划开发一种简单而经济的方法，将邻苯二甲酸酯模拟物共价地附着在聚氯乙烯上，赋予易碎的聚氯乙烯可塑性，同时防止小分子的迁移，这些小分子会浸出并代谢成干扰内分泌的化学物质。邻苯二甲酸盐目前每年以百万吨的规模使用，但与许多健康问题有关。该项目的成功成果将提供一种新的战略，使用可扩展到工业应用的方法来取代邻苯二甲酸酯增塑剂，减轻消费品和环境中内分泌干扰性邻苯二甲酸酯的积累。通过化学键将增塑剂附着在PVC上也可以提高使用柔性PVC的消费品的使用寿命。此外，这项研究将为合成有机化学和材料科学领域的研究生和本科生提供跨学科的培训，教育他们在未来做出重大贡献所需的工具。研究生和本科生都将在PI的指导下参加专业活动，在会议上展示他们的工作，并积极参与根据他们的研究成果编写手稿。技术概述：该项目需要一种简单而经济的方法，将邻苯二甲酸酯模拟物共价连接到PVC上，作为标准邻苯二甲酸酯增塑剂的替代品。由于邻苯二甲酸酯现在每年以百万吨的规模使用，因此需要一种化学性质相似，但不会从PVC基质中迁移的替代品。小分子邻苯二甲酸酯增塑剂从PVC产品中浸出，随着时间的推移改变PVC的性能，并向环境中释放潜在的内分泌干扰化学物质。在不含铜的条件下，采用简单的Huisgen 1,3-偶极环加成法将烷基叠氮化物和二烷基乙炔二羧酸盐在中等温度下加成，制备了含有多种烷氧基的邻苯二甲酸酯的1,2,3-三唑，以模拟邻苯二甲酸酯增塑剂。这些邻苯二甲酸酯模拟物将通过对商业制备的PVC进行改性，或通过含邻苯二甲酸酯三唑模拟物的乙烯基单体与氯乙烯共聚，与PVC共价连接。此外，含邻苯二甲酸酯模拟物的单体共聚物将被制备成与PVC共混的聚合增塑剂。改性PVC材料的性能将被广泛评估，以评估Tg降低、均匀性作为时间函数、迁移潜力、聚合物形态和弹性体行为所表明的塑性。将分析聚合物增塑剂与PVC的混相。这些材料经水解和随后的萃取后的稳定性将根据ASTM标准进行测试。研究了这些聚合物结合的三唑的热分解和光分解。

NON-TECHNICAL SUMMARY:This award will support the research program of Prof. Rebecca Braslau at the University of California Santa Cruz in developing alternatives to phthalate plasticizers used in polyvinyl chloride (PVC) formulations. Professor Braslau and her students plan to develop simple and economic methods to covalently attach phthalate ester mimics to PVC, imparting plasticity to otherwise brittle PVC, while preventing migration of small molecules that can leach out and become metabolized into endocrine disrupting chemicals. Phthalates are currently utilized on the million-ton scale annually, yet are implicated in a number of health problems. A successful outcome of this project will provide a new strategy to replace phthalate plasticizers using methodology that is scalable to industrial applications, mitigating the buildup of endocrine disrupting phthalates in consumer products and in the environment. The attachment of the plasticizer to PVC by chemical bonds may also improve the lifetime of the consumer products using flexible PVC. In addition, this research will provide interdisciplinary training to graduate and undergraduate students in the fields of synthetic organic chemistry and materials science, educating them with the tools they will need to make significant contributions in the future. Both graduate and undergraduate students will be mentored by the PI to participate in professional activities, presenting their work at meetings, and taking an active part in the preparation of manuscripts stemming from their research findings. TECHNICAL SUMMARY: This project entails a simple and economic method to covalently attach phthalate ester mimics to PVC, as a substitute for standard phthalate plasticizers. As phthalate esters are now used on the million-ton scale annually, a substitute is desirable that is chemically similar, but which shows no migratory ability from the PVC matrix. Small molecule phthalate plasticizers leach from PVC products, changing the properties of the PVC with time, and releasing potential endocrine disrupting chemicals into the environment. A simple Huisgen 1,3-dipolar cycloaddition of alkyl azides and dialkyl acetylenedicarboxylates at moderate temperatures in the absence of copper will be utilized to prepare 1,2,3-triazoles bearing ortho-esters containing a variety of alkoxy groups, to mimic phthalate esters plasticizers. These phthalate mimics will be covalently linked to PVC, either by modification of commercially prepared PVC, or by copolymerization of vinyl monomers bearing ortho-diester triazole phthalate mimics with vinyl chloride. In addition, copolymers of monomers bearing phthalate mimics will be prepared as polymeric plasticizers to be blended with PVC. The properties of the modified PVC materials will be extensively evaluated to assess plasticity as indicated by Tg depression, homogeneity as a function of time, migratory potential, polymer morphology, and elastomeric behavior. The polymeric plasticizers will be analyzed for miscibility with PVC. The stability of these materials upon subjecting them to hydrolysis and subsequent extraction will be tested according to ASTM standards. The thermal and photodecomposition of these polymer-bound triazoles will be studied.