Greener, cleaner, composites

本提案的总体目标是发展对聚合物基复合材料的加工制造和性能的基本理解，其中基体材料部分或全部来自生物基原料。此外，在此次合作中获得的知识将使FAC技术公司能够增加生物基树脂制造的复合部件的商业吸收。环氧树脂是高性能复合材料的首选基质，因为其卓越的机械性能，包括高模量，高强度和有利的加工特性，如低粘度。环氧树脂约占全球热固性树脂市场的70%。双酚A二缩水甘油醚（DGEBA）是制备环氧树脂最广泛使用的单体。DGEBA主要是由化石资源合成的。因此，显然迫切需要探索可再生资源衍生的替代热固性化学，以减少我们对化石资源的依赖和对地球的影响。近年来，人们对从生物材料中提取的树脂和纤维的兴趣激增，这是由于人们希望变得更加环保，减少对日益减少的化石燃料供应的依赖。虽然环氧聚合物通常具有良好的机械性能，但由于固化热固性中交联程度高，它们缺乏韧性。近年来，伦敦帝国理工学院（Imperial College London）的Kinloch等研究小组（Carolan博士曾是Kinloch教授的研究员）缓解了这种缺乏韧性的情况。这是通过在组分最终固化之前向树脂共混物中添加添加剂来实现的。微米级的橡胶颗粒，无论是预先形成的还是通过反应诱导相分离形成的，都被证明是最有效的。生物基树脂还存在韧性不足的问题。迄今为止，还没有对生物基树脂（或含有生物基和传统石油衍生热固性混合物的混合树脂）的“增韧性”进行过广泛的研究。“增韧性”是指每加入一单位添加剂，热固性聚合物的韧性增加的量。目前尚不清楚同样的增韧机制是否适用，或者在多大程度上适用。这些知识对于增加可再生原料中更环保树脂的使用至关重要。未来领袖奖学金将使Carolan博士站在英国复合材料行业转型的最前沿。事实上，文献中有一些证据表明，石油衍生树脂和生物衍生树脂的共混物在固化反应中会自然地相分离。Carolan博士已经证明，通过控制固化反应的速率，可以深刻地影响相分离系统的最终微观结构。这可能意味着混合化石和生物衍生树脂的使用可能比其他树脂提供协同效益。这将在拟议的研究金期间进行调查。这项工作在本质上是多学科的，将连接材料科学、化学和机械工程领域。此外，通过考虑树脂分子组成的影响，研究人员将在复合结构的长度尺度上建立桥梁，从分子水平到纳米尺度和介观纤维-基质界面行为，最后考虑复合结构本身。决定最终微观结构的时间因素（或反应速率）也将被考虑。这种系统级设计方法，从分子到组件，从“罐到部件”，是工业上真正的创新理念，将使FAC技术能够使用越来越少的材料更好地设计复合材料结构，同时从结构中提取更多的功能，并使Carolan博士成为英国复合材料行业的领导者之一。

The overall aim of this proposal is to develop a fundamental understanding of the processing fabrication and performance of polymer based composites where the matrix material is either partially or wholly derived from bio-based feedstock. Moreover, the knowledge gained during this Fellowship will allow FAC Technology to increase commercial uptake in composite components manufactured from bio-based resin.Epoxy resin is the matrix of choice for high-performance composites due to their outstanding mechanical properties, including high modulus, high strength and favourable processing characteristics, e.g. low viscosity. Epoxy accounts for approximately 70% of the thermoset resin market worldwide. Diglycidylether of bisphenol A (DGEBA) is the most widely used monomer to formulate epoxy resins. DGEBA is mostly synthesised from fossil resources. Thus, there is clearly a pressing need to explore alternative thermoset chemistry that can be derived from renewable resources to reduce our dependence on fossil resources and our impact on the planet.Interest in resin and fibres derived from biological materials has surged in recent years, fueled by a desire to become more environmentally friendly and reduce dependence on dwindling fossil fuel supplies. Although epoxy polymers have generally good mechanical properties, they suffer from a lack of toughness due to the high degree of crosslinking in the cured thermoset. This lack of toughness has been alleviated in recent years by groups such as Kinloch et al at Imperial College London (Dr. Carolan was previously a Fellow with Prof. Kinloch). This is achieved by adding additives in to the resin blend before final cure of the component. Micron scale rubber particles, either preformed or formed via reaction induced phase separation have proven to be most effective. Bio-based resins also suffer from lack of toughness. To date, no extensive study on the 'toughenability' of bio-based resins (or hybrid resin containing a mixture of bio-based and conventional petroleum derived thermosets) has been carried out. 'Toughenability' refers to the amount by which the toughness of a thermoset polymer increases per unit additive added. It is currently unknown whether, or how well, the same toughening mechanisms will apply. Such knowledge is absolutely critical to increase the usage of more environmentally friendly resins from renewable feedstocks. The Future Leaders Fellowship will enable Dr. Carolan to be at the forefront of this transition in the UK composites industry.Indeed, there is some evidence in the literature to suggest that blends of petroleum derived resins and bio-derived resins will naturally phase separate during the curing reaction. Dr. Carolan has already demonstrated that by controlling the rate of the curing reaction, it is possible to profoundly influence the final microstructure of a phase separated system. This potentially means that the use of hybrid fossil- and bio-derived resins may offer synergistic benefits over the other. This will be investigated during the proposed Fellowship.The work proposed is multi-disciplinary in nature and will bridge the fields of materials science, chemistry and mechanical engineering. Moreover, by considering the effect of the molecular makeup of a resin, the Fellowship will bridge the length scales within a composite structure from the molecular level, through to the nanoscale and mesoscopic fibre-matrix interface behaviour and finally considering the composite structure itself. The element of time (or reaction rate) in determining the final microstructure will also be considered. This system level design approach, from molecule to component and from 'Pot to Part', is a truly innovative idea in industry and will allow FAC Technology to better design composite structure using less and less material while extracting ever more functionality from the structure and position Dr. Carolan as one of the industry leaders in composite materials in the UK.