Hydrolysis of hydrophobic poly(2-oxazoline)s and their subsequent modification via aza-Michael addition

Partially hydrolysed poly(2-oxazoline)s possess unique properties. However, much of the focus in this area has been on water soluble poly(2-oxazoline)s. Where hydrophobic poly(2-oxazoline)s have been used, this is often for selective hydrolysis. However, hydrolysis of very hydrophobic polymers could lead to interesting solution behaviour. Herein, we describe universal conditions for the hydrolysis of poly(2-alkyl-2-oxazoline)s suitable for both hydrophobic and hydrophilic 2-oxazolines. We show that the system utilised gives comparable rates to that of water alone for poly(2-ethyl-2-oxazoline). In addition, poly(2-fatty acid-2-oxazoline) was hydrolysed using the developed system and was found to proceed in a controlled manner allowing the targeting of specific degrees of hydrolysis, albeit much slower than for poly(2-ethyl-2-oxazoline). Finally, we demonstrate the partial functionalisation of poly(2-oxazoline)-poly(ethylene imine) co-polymers via aza-Michael addition.

Synthesis of miktoarm star-shaped and inverse star-block copolymers by a combination of ring-opening polymerization and click chemistry

Based on the combination of the “arm-first” and “core-first” strategies, the miktoarm star-shaped copolymer PLLA2PCL2 and the inverse star-block copolymer (PCL-b-PLLA)2-core-(PCL-b-PLLA)2 were designed and synthesized by the combination of ring-opening polymerization (ROP) and a click reaction. The miktoarm star-shaped copolymer PLLA2PCL2 was synthesized by a click reaction of an azido macroinitiator PLLA2(N3)2 and HC≡C-PCL. The inverse star-block copolymer (PCL-b-PLLA)2-core-(PCL-b-PLLA)2 was synthesized by a click reaction of an azido macroinitiator (PCL-b-PLLA)2(N3)2 and HC≡C-PCL-b-PLLA. The structures of these star polymers were confirmed by nuclear magnetic resonance (NMR), Fourier-transform infrared (FT-IR) spectroscopy and gel permeation chromatograph (GPC). The inverse star-block copolymer could be used to study the potential relationship between polymer structure and properties, which has a unique structure and good crystallization properties.

Synthetic methodologies and spatial organization of metal chelate dendrimers and star and hyperbranched polymers

The synthetic methodologies, physico-chemical peculiarities, properties, and structure of metal chelate dendrimers and star and hyperbranched polymers are considered.