Main Group Catalysis for Sustainable Piezoelectrics

该项目的总体目标是研究新的主族催化剂是否可以用来生产具有有趣可调性能的可持续铁电材料。在这个项目中，将研究利用N-杂环膦化合物(NHP-X)的极性性质来进行丙交酯和其他环酯的开环聚合(ROP)研究(与洛斯阿拉莫斯国家实验室合作)。除了文献中报道的五元NHP-X催化剂外，还将应用一系列新的催化剂支架来研究N-取代基、P-取代基、N-P-N角和pi离域对所得聚酯的聚合物性能的影响。由NHP催化剂提供的改变聚酯微观结构的能力(即规整度、链长、端基、制备共聚物的能力)为发展结构-活性关系和测量此类聚合物的铁电性能提供了独特的机会。项目目标：目标1：研究已知和新的NHP-X物种在ROP和其他反应中的催化效率。(使用标准的空气敏感化学技术，包括Schlenk技术，并利用分析化学方法进行表征，如核磁共振(核磁共振)光谱、质谱学和单晶X射线衍射。)目的2：考察单体范围、价态和解聚潜力。(将监测聚合反应，并将使用核磁共振光谱、差示扫描量热法、粉末X射线衍射和MALDI-TOF质谱仪等技术对产品进行分析。)目的3：研究NHP-X衍生聚合物的介电和铁电性能。(将与机械工程部合作，通过测量材料在电场、温度变化和压力作用下极化的变化，来测量聚合物的铁电、热释电和压电性能。)

The overall project of the goal is to investigate whether new main group catalysts can be used to produce sustainable ferroelectric materials with interesting tuneable properties.In this project, the exploitation of the polar nature of N-Heterocyclic phosphine compounds (NHP-X) to undertake ring-opening polymerisation (ROP) studies on lactide and other cyclic esters (in concert with Los Alamos National Lab) will be investigated. Beyond the 5-membered NHP-X catalysts reported in the literature, a range of new catalyst scaffolds will be applied to investigate the effect of N-substituent; P-substituent; N-P-N angle and pi-delocalisation upon the polymer properties of the resulting polyester. The ability to vary the microstructure of polyesters offered by NHP catalysts (i.e. tacticity, chain length, end groups, ability to prepare copolymers) provides a unique opportunity to develop structure-activity relationships and measure the ferroelectric properties of such polymers. Aims of the project:Aim 1: Investigation of the catalytic efficacy of known and new NHP-X species in ROP and other reactivity. (Using standard air sensitive chemistry techniques including Schlenk techniques, and utilising analytical chemistry methods for characterisation such as nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and single crystal X-ray diffraction.) Aim 2: Interrogation of monomer scope, valorization and depolymerization potential. (Polymerisations will be monitored and the products will be analysed using techniques such as NMR spectroscopy, differential scanning calorimetry, powder X-ray diffraction and MALDI-TOF mass spectrometry.) Aim 3: Investigation of the dielectric and ferroelectric properties of NHP-X derived polymers. (Ferroelectric, pyroelectric and piezoelectric properties of the polymers will be measured in collaboration with the Department of Mechanical Engineering, by measuring the change in polarisation of the material under the application of electric field, temperature change and pressure.)