Abstract:
Additive manufacturing or 3D printing is a process for fabricating 3D objects by adding successive layers of materials on top of each other. Among various 3D printing approaches, the photo-assisted additive manufacturing, which is commonly known as vat photopolymerisation, is extremely attractive. During this process, the objects are produced via photopolymerisation reactions of monomers, and novel physicochemical properties are gained. This technique has environmental, economic, and production benefits. The high resolution achieved using vat photopolymerisation, together with the new properties, have resulted in new implementations such as biomedical devices or electrically conductive devices. However, harmful printing conditions such as UV light, the plastic pollution caused by the wasted products, or finite functionalities of the products may limit the further application of the final manufactured products. In light of the current challenges, this thesis is directed at the design and preparation of novel sustainable and eco-friendly photopolymers with specific functions, which are rapidly printable in mild conditions.
In Chapter 1, a general introduction of photo-assisted additive manufacturing techniques and photopolymers is discussed. Chapter 2 and Chapter 3 outline the review on thiol-ene/yne systems and the electrically conductive polyaniline in photo-assisted additive manufacturing, respectively. In Chapter 4, synthesised aliphatic polycarbonate is used as the “yne” component in the thiol-yne photoresin, introducing outstanding degradability to the fabricated 3D structures. This research presents a possible solution to the plastic pollution problem, allowing responsible, sustainable acceleration of the polymer-based 3D printing industry. In Chapter 5, a thiol-yne photoresin that is 3D printable in visible light is reported. This work illustrates the possibility of replacing traditional photoinitiators with photoredox catalysts, particularly in the visible light range. Thus, enriching the photoresin formulations for the polymer-based 3D printing industry. Chapter 6 details an electrically conductive polyaniline hydrogel fabricated via a photopolymerisation process, which was used to prepare optical memory devices. This work broadens the application of polyaniline in photo-assisted additive manufacturing. Chapter 7 focuses on a hydrogel photoresin filled with hydrophilic oligoanilines that was used in fabricating degradable electrically conductive 3D structures. This research provides the inspiration for fabricating eco-friendly functional 3D hydrogel products
in an easy and economical way. Chapter 8 describes a broad summary of the work presented and the overall conclusion in this thesis. Future work is also discussed.