Switchable Catalysis for Block Copolymer Compatibilization of Plastic Waste

塑料对环境既是朋友又是敌人。虽然塑料污染构成了严重的威胁，但塑料也作为太阳能电池、风力涡轮机叶片、可充电电池和轻型电动汽车的关键部件，为绿色革命提供了动力。塑料是减少我们对化石燃料和二氧化碳排放的依赖的核心，通过它们在建筑绝缘和飞机轻型部件中的使用。它们还通过延长保质期和减少食物浪费来促进粮食安全。目前的塑料生产和报废管理系统是不可持续的，迫切需要用可再生资源制造塑料。塑料垃圾提供了丰富而有吸引力的替代原料，但2015年之前生产的所有塑料中约有60%被丢弃，目前只有10%的塑料被回收利用。开发将塑料废弃物升级为比原来更高质量或价值的产品的方法是一个有吸引力的目标，因为回收行业的现代化有可能使废物价值化，创造就业机会并产生经济收入。最近对可持续塑料的推动导致其市场快速增长，当它们进入并污染传统回收流程时可能会出现问题。回收导致材料性能变差的原因之一是，当两种不同的塑料一起回收时，它们不能很好地混合;这就像试图将油与水混合一样。这在两种塑料之间的界面处产生了张力，即使是少量的“错误”塑料污染也会污染并破坏整个回收批次。这一挑战可以通过使用与两种类型的塑料（即“水”和“油”）相互作用的分子来克服，通过充当分子“钉”来在界面处连接两种塑料，从而产生更坚固的材料。这些分子“斯台普斯”需要两个不同的部分，一个与“油”相互作用，一个与“水”相互作用。这个项目的目标是冒险的策略，使这些分子“斯台普斯”，从我们的增容剂互补工作的建设。将开发新的催化剂系统来制备“主食”的两种不同组分，该项目独特地专注于扩大可以在这两种不同化学反应之间转换的分子开关的范围。目前尚不清楚该项目中设计的制备分子“斯台普斯”的可切换策略，但这项新技术将通过使传统塑料与可持续塑料污染物混合，有助于防止可持续塑料污染的未来回收流。这是一个重要而及时的挑战，因为不同类型塑料的分离可能非常昂贵和耗时。如果成功，该项目将通过使用废弃的塑料废物作为原料，并将其转化为新材料，甚至可能比原始塑料具有更好的性能，从而从废物中创造财富。

Plastics are both a friend and foe to the environment. While plastic pollution poses a severe threat, plastics are also powering the green revolution as key components of solar cells, wind turbine blades, rechargeable batteries and lightweight electric cars. Plastics are central to reducing both our reliance on fossil fuels and CO2 emissions, through their use in building insulation and lightweight components of aeroplanes. They also contribute towards food security by extending shelf life and reducing food waste. Current plastic production and end-of-life management systems are unsustainable, and there is an urgent need to make plastics from renewable sources. Plastic waste offers a plentiful and attractive alternative feedstock, yet approximately 60% of all plastic produced before 2015 has been discarded, and only 10% of plastics are currently recycled. Developing methods of upcycling plastic waste into products of higher quality or value than the original is an attractive target, as modernising the recycling industry has the potential to valorise waste, create jobs and generate economic revenue.The recent drive for sustainable plastics has led to their rapid market growth, which can be problematic when they enter and contaminate conventional recycling streams. One of the reasons that recycling leads to poorer material properties is that when two different plastics are recycled together, they do not blend well; this is like trying to mix oil with water. This creates tension at the interface between the two plastics, and even a small amount of contamination with the "wrong" plastic can contaminate and ruin an entire batch of recycling. This challenge can be overcome by using a molecule that interacts with both types of plastic (i.e. the "water" and the "oil"), by acting as a molecular "staple" to connect the two plastics at the interface and thus create a stronger material. These molecular "staples" require two different sections, one that interacts with the "oil" and one that interacts with the "water". This project targets adventurous strategies to make these molecular "staples", building from our complementary work on compatibilizers. New catalyst systems will be developed to prepare the two distinct components of the "staple", and this project uniquely focuses on expanding the range of molecular switches that can convert between these two different chemical reactions. Switchable strategies to prepare the molecular "staples" designed in this project are currently unknown, but this new technology will help to futureproof recycling streams against contamination with sustainable plastics, by enabling conventional plastics to be blended with sustainable plastic contaminants. This is an important and timely challenge, as the separation of different types of plastics can be prohibitively expensive and time-consuming. If successful, this project will create wealth from waste, by using discarded plastic waste as a feedstock, and converting it into new materials that may even have better properties than the original plastics.