Controlled/living radical polymerization of multi-vinyl monomer towards hyperbranched polymers for biomedical applications

This thesis describes a novel route for the preparation of hyperbranched polymers. The aim is to produce veritable hyperbranched polymers from commercially available multi-vinyl monomers via in situ deactivation-enhanced ATRP at high conversion without crosslinking. The strategy is to alter the growth manner of polymerization by controlling the kinetic chain length together with manipulating chain growth conditions to achieve facile syntheses of 3D structured multifunctional materials.Chapter 1 provides a general introduction to the controlled/living radical polymerization, basic concepts of hyperbranched polymers, their preparation methods and their applications in biomedical field.Chapter 2 focuses on the study of different ATRA reaction system, including normal ATRA, ARGET ATRA and in situ DE-ATRA, for a better kinetic control of the polymerization of multi-vinyl monomers.Chapter 3 covers the hyperbranched homopolymers prepared by in situ enhanced deactivation ATRP, illustrating the ‘vinyl oligomer combination’ strategy as a universal approach towards hyperbranched polymers.Chapter 4 focuses on the synthesis of hyperbranched poly(PEGDA) as an efficient photo-crosslinked hydrogel.Chapter 5 demonstrates the synthesis of degradable cationic hyperbranched copolymers as efficient gene transfection agent. Also the significance of branching on transfection is explored.Chapter 6 summarises all the research presented in this thesis. Moreover, some possible research routes for the investigation in the future are listed in this part