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Chapter 1 provides a general introduction to the main concepts which are applied throughout this thesis and surveys the reported synthetic routes to functional polyesters and polycarbonates as well as applications of alkene-functional polycarbonates prepared by ROP in the published literature.\ud Chapter 2 describes the organocatalyzed synthesis of P(L-malOCA) and PLLA polymers derived from activated monomers (OCAs) of L-lactic and L-malic acids. Ion pairs of pyridine and 4-methoxypyridine with L-lactic acid and β-benzyl α-(L)-malate were prepared and were employed as single initiator/catalyst systems for the ROP process. Analysis of the polymers via MALDI-ToF mass spectrometry provided an insight into the different side-reactions which occurred during the ROP, especially for the higher molar mass polyesters. The stereoregularity of these polymers was investigated via 1H homo-decoupled and 13C NMR spectroscopy techniques. Polymers of higher molar mass were found to be almost 100% isotactic, whereas lower molar mass polymers displayed an atactic nature. The thermal analysis of these polymers revealed the highly crystalline and thermal resisting nature of PLLA with high melting temperatures, while P(L-malOCA) polymers remained in amorphous state as a consequence of their microstructure.\ud Chapter 3 describes the organocatalytic ring-opening copolymerisation of L-lactide with three functional monomers, two allyl functional 6-membered cyclic carbonates, 6-methyl-5-allyloxycarbonyl-1,3-dioxan-2-one (MAC), 2-allyloxymethyl-2-ethyltrimethylene carbonate (TMAC) and an isopropyl functional 5-membered cyclic phosphate, 2-isoproxy-1,3,2-dioxophospholane 2-oxide (iPP). 1H and 13C NMR spectroscopy and SEC provided evidence that copolymers of defined composition and microstructure were synthesised employing a wide array of novel or already reported organocatalytic systems which enabled the regulation of the polymerisation activity of each comonomer selectively. Specifically, the copolymerisation of lactide with the cyclic phosphate showed the large difference in reactivity of the two monomers leading to the synthesis of block-like or gradient copolymers with a first PLA block followed by a shorter polyphosphate block, rather than a more statistical structure, which was the desired result. The change to another family of monomers, the 6-membered cyclic carbonates improved the copolymerisation behaviour of lactide and shifted the microstructure of the materials into a more random nature. Thermal analysis of the polymers revealed their full miscibility in the melt through a single Tg, showcasing the statistical nature. Furthermore, PLLA’s crystallinity could be retained for up to 22% carbonate content in the copolymer structure, a value which is unprecedently high, and is a consequence of the random placement of carbonate units in the copolymers.\ud Chapter 4 describes the investigation pf the homo-polymerisation of two functional 8-membered-N-cyclic carbonates (allyl and propargyl) catalysed by a number of organic catalysts. Subsequently, the simultaneous ROCOP of the two comonomers with lactide was studied. The judicious choice of catalytic system lead to statistical copolymers of the desired microstructure and molecular weight. Reactivity ratio studies, detailed 1H/13C NMR spectroscopic analyses and MALDI-ToF MS analyses provided convincing data for the randomness of the copolymers. Thermal analyses by the means of DSC and TGA provided data for the crystallinity of the copolymers of moderately high carbonate content.\ud Chapter 5 describes the semi-crystalline alkene- and alkyne-functional P(LLA-co-A8NC) & P(LLA-co-P8NC) statistical copolymers which were subjected to stereocomplexation studies with their enantiomerically opposite counterparts, and with PDLA. These new materials displayed increased crystallinity compared to their parent enantiopure copolymers and this translated into enhanced thermal stability, evidenced by DSC and TGA studies. Moreover, taking advantage of the terminal alkene functionality which - as a consequence of the highly statistical nature of the copolymers – was selectively located into the copolymer chain, post-ROP photoinitiated thiol-ene reactions were performed. A wide variety of mono-functional thiols were successfully attached to the P(LLA-co-A8NC) copolymers as evidenced by 1H/13C NMR spectroscopy, SEC, DSC and TGA analyses.\ud Chapter 6 provides a general summary of Chapters 2-5, and explores opportunities for further work that may be productively undertaken based on the results presented in this thesis.\ud Chapter 7 lists experimental protocols and spectroscopic data for the materials presented in this thesis.\ud An Appendix is provided in which all supporting spectroscopic data described in all Chapters is shown.\ud