An environmentally friendly plastic made from cellulose and water?

Plastics offer many advantages - they are light, cheap and adaptable, hence they are widely used in our daily lives. However, the production, processing and disposal of plastic presents significant and complex environmental and health challenges. In this respect, the environmentally friendly processing of reusable and recyclable plastics derived from plant-based raw materials would be an ideal solution. So far, the technological challenges in this area have been very great. However, researchers at the University of G?ttingen in Germany have now found a sustainable method - hydrosetting, which uses water under normal conditions - to process and reshape a new type of hydroplastic polymer called cellulose cinnamate (CCi). The research is published in Nature Sustainability. Plastics are polymers, which means that their molecular structure is made up of a large number of similar units linked together. Currently, most plastics are made from petrochemical feedstocks, the extraction and disposal of which have significant environmental impacts. In contrast, cellulose, which is the main constituent of plant cell walls, is the most abundant natural polymer on earth and is an almost inexhaustible source of raw material. By slightly modifying a very small portion of the cellulose chemistry by introducing a group of 'cinnamoyl' enzymes, the researchers were able to make a specific CCi suitable for the formation of a new type of bioplastic with hydroplastic (i.e. soft and mouldable in contact with water) polymers. This means that it can be moulded using little more than water at the usual temperature and pressure. This unique method - known as hydrosetting - allowed the researchers to produce a variety of shapes simply by immersing the bioplastic in water and allowing it to air-dry. The moulded shapes maintained their long-term stability and could be remoulded again and again into a variety of 2D and 3D shapes. Although the plastic should not be used in direct contact with water - as it would lose its shape - it can retain water and be used in wet conditions. CCi's bioplastics showed high-quality mechanical properties compared to plastics that are currently in widespread use. "Our research provides a feasible method for designing other environmentally friendly hydroplastics from renewable resources," explains Professor Kai Zhang of the University of G?ttingen, "This should open up new avenues of research, stimulating the exploration of other sustainable bioplastics with superior mechanical properties and new characteristics.