Executive Summary : | Polymers, both biodegradable and non-biodegradable, are economically important for their wide-spread applications. Functional polyesters are highly desirable synthetic targets due to their wide-spread applications. Ring opening polymerization has been useful for synthesis of pharmaceutically important polymers like poly(lactides) (PLA), but its broader scope is limited due to the lack of functional units in PLA backbone. Polycondensation is a widely accepted method for synthesis of industrially important polyesters, but it requires continuous removal of byproducts to accelerate the reaction forward and generate high molecular weight polymers. This proposal proposes a versatile polycondensation methodology based on transesterification reaction from structurally diverse pentafluorophenyl (PFP)-based activated diesters and functional diols. The proposed method aims to explore the impact of "stoichiometric imbalance" between reacting monomers and "monofunctional impurity" of an auxiliary functional alcohol on the molecular weight and end-group functionality of targeted polyesters. By taking excess of the reactive diester, PFP-ester terminated polyesters can be produced, allowing for site-selective post-polymerization functionalization (PPF) with desired functional alcohols only at the end-groups without affecting non-reactive esters of the backbone. This method will also enable the synthesis of hydroxy-terminated polyesters and PFP-ester functionalized hyperbranched polymers, producing highly branched functional polymers by PPF. The proposed method also aims to synthesize a new family of degradable, pH-responsive, and cationic polyesters, examining their potential in biomedical applications. The impact of structural variation, end-groups, and polymer architectures on thermal properties, degradability, and self-assembly behavior under different conditions will be investigated in detail. |