RAMP, and RAFT, and SUMI oh my!

By August 27th, 2018

The RAMP Centre was acknowledged in a chapter of a recently published ACS Symposium Series book on the topic of RAFT-single unit monomer insertion (RAFT-SUMI). The experiments took place over a number of years (and students) but helped us to identify some issues and refine our methods to achieve results more comparable with standard bench-top chemistry.

Click the title below for a link to the published chapter.

RAFT 20 Years Later: RAFT-Synthesis of Uniform, Sequence-Defined (Co)polymers

1 CSIRO Manufacturing, Research Way, Clayton, VIC 3168, Australia
2 School of Chemistry, Monash University, Clayton, Vic 3800, Australia
3 Insitute for Materials Research, Universiteit Hasselt, B-3590 Diepenbeck, Belgium
4 Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB, Eindhoven, The Netherlands
5 Centre for Advanced Macromolecular Design and Australian Centre for NanoMedicine, School of Chemical Engineering, University of NSW, NSW 2052, Australia

Abstract

This paper focuses on one of the next directions in the evolution of reversible addition-fragmentation (RAFT) polymerization, namely, progress towards the synthesis of discrete or uniform, sequence-defined (co)polymers. Following a brief review of RAFT-single unit monomer insertion (RAFT-SUMI), we describe recent developments in the field. We point to difficulties in achieving consecutive RAFT-SUMI and report two strategies for overcoming the issue of initiator-derived by-products. We show that the selection of RAFT agent is critical in selective RAFT-SUMI of N,N-dimethylacrylamide (DMAm) into a trithiocarbonate in aqueous solution. Finally we recount on the use of photoRAFT- or PET-RAFT-SUMI in the high yield synthesis of discrete oligomers comprising two or more consecutive SUMI steps.

 

GPC results from publication

Overlaid GPC traces indicating outcome of high throughput experiment conducted on Chemspeed® platform. The experiment involved sequential addition of [DMAm]:[VA044]=1.0: 0.01 to [9]=1.0 in aqueous media at 70 °C. The iteration time (120 min) was chosen such that there was complete conversion of monomer and initiator in each iteration. Molar mass increases from right to left (i.e., leftmost trace is PDMA4, which comprises an average of 8 units of PDMA).