Dr Lian Hutchings
(email at firstname.lastname@example.org)
Deputy Director of the Durham Centre for Soft Matter
My interests lie in the field of synthetic polymer chemistry and specifically the synthesis of polymers which are well controlled in terms of molecular weight, composition, functionality and chain architecture. We also collaborate extensively in studies which seek to understand the correlation between structure and properties. We exploit a variety of living/controlled polymerization mechanisms to achieve that aim including living anionic polymerization, ATRP and RAFT
DendriMacs, HyperMacs and HyperBlocks1,2
It is well understood that the architecture of polymer molecules, particularly branching has a strong influence on the physical properties. Experimental tests of current theories for the correlation of molecular architecture and physical properties require model polymers with precisely defined structures. As the theoreticians develop increasingly sophisticated tools the challenge for the synthetic polymer chemist is to create evermore complex yet well defined branched architectures.
In recent years we have developed a very versatile methodology to synthesise a new generation of long chain branched polymers we call DendriMacs and HyperMacs1. These architectures are essentially long chain branched analogues of dendrimers and hyperbranched polymers - analogous not only in structure but in the strategy used to prepare them. They differ from dendrimers and hyperbranched polymers only in having a well defined polymer chain between branch points. They have been used as the ultimate long chain branched polymer for structure property correlation studies; leading to validation of the most advanced theoretical tools for the prediction of the rheology of branched polymers. More recently block copolymeric HyperMacs - HyperBlocks have shown promise as a novel branched thermoplastic elastomers2.
Polymers containing functionality at one (or both ends) of the polymer chain can, when used in relatively small quantities, significantly modify interfaces, be it a polymer/air interface, air/liquid interface or if the functionalities are reactive, functionalized polymers can be used to stabilize a polymer blend, via reactive blending. We have an ongoing collaborative research program (with Dr Richard Thompson) investigating the surface modifying properties of multi end functionalized polymer additives for a variety of applications. Multi functional fluoroalkyl additives have been shown to be particularly effective at rendering the surface of the polymers extremely hydrophobic with less than 0.5% of additive required to modify the surface of a polystyrene film to give PTFE like surface properties. See below the relationship between contact angle (with water) and the concentration of polymer additive.
Control of sequence distribution in copolymers6
The control of sequence distribution in polymers is something that nature achieves with consummate ease with sequence-defined polymers such as nucleic acids and proteins being the fundamental building blocks of life. However the ability to reproduce this level of control in synthetic polymer chemistry is a highly challenging and often neglected area of research, despite the possibility that synthetic polymers with controlled monomer sequences could play a significant role in the future of materials science. Some progress has been made for step wise condensation polymerisation using protection/deprotection reaction cycles on solid supports but the control of sequence for chain growth polymerisation in solution is an altogether more challenging problem. Possibly the simplest form of sequence control in chain growth polymerisation is the alternating copolymer and we have recently begun to investigate new combinations of monomers capable of generating alternating sequences. Our longer term goal is to create polymers from 3 or 4 comonomers which as a result of inherent differences in reactivity polymerise in a strictly controlled sequence.
- Hutchings, LR; Dodds, JM; Rees, D; Kimani, SM; Wu, JJ; Smith, E. HyperMacs to HyperBlocks: A Novel Class of Branched Thermoplastic Elastomer. Macromolecules, 2009, 42, 8675-8687
- Hutchings, LR. DendriMacs and HyperMacs. Emerging as more than just model branched polymers. Soft Matter. 2008, 4, 2150-2159
- Hutchings, LR; Sarih, NM; Thompson, RL. Multi-end functionalised polymer additives synthesised by living anionic polymerisation - the impact of additive molecular structure upon surface properties. Polymer Chemistry, 2011, 2, 851-861
- Pillay Narrainen, A; Hutchings, LR; Ansari, I; Thompson, RL; Clarke, N. Modifying and Managing the Surface Properties of Polymers - A Mini Reveiw. Polymer International, 2008, 57, 163-170.
- Pillay Narrainen, A; Hutchings, LR; Ansari, I; Thompson, RL; Clarke, N. Multi-end functionalized polymers; additives to modify polymer properties at surfaces and interfaces. Macromolecules, 2007, 40, 1969-1980.
- Natalello, A; Hall, JN; Eccles, EAL; Kimani, SM; Hutchings, LR. Kinetic Control of Monomer Sequence Distribution in Living Anionic Copolymerisation. Macromoecular Rapid Communications, 2011, 32, 233-237.