Jump to main content
Jump to site search


Ultra-fast aqueous polymerisation of acrylamides by high power visible light direct photoactivation RAFT polymerisation

Author affiliations

Abstract

The effect of visible LED power (λmax = 402 nm, 451 nm) on kinetics and control of direct photoactivation RAFT polymerisations of acrylamide and dimethylacrylamide are investigated. By increasing power supplied to the LEDs from 6 to 208 W, the polymerisation time required to reach >85% conversion is reduced from 12 hours to 11 minutes for acrylamide. Similar conversions are shown to be obtainable in 5 minutes for dimethylacrylamide, all without any exogenous photoinitiator or catalyst. This increase in polymerisation rate is attributed to an increase in both photon flux and a coincident increase in polymerisation temperature at higher light intensities. With both 402 nm and 451 nm LEDs exciting the same n → π* electronic transition, little difference in rate of polymerisation is seen between the two light sources. Minimal reduction in polymerisation control is observed at high irradiation intensity for acrylamide, while an increased production of low molecular weight dead chains is observed for dimethylacrylamide. This is shown to be mitigated by controlling the polymerisation temperature to 17 °C which caused both a reduction in low molecular weight tailing and an increased polymerisation time. Visible light direct photoactivation RAFT is also shown to have application in the synthesis of ultra-high molecular weight acrylamide polymers (Mn > 1 000 000 g mol−1).

Graphical abstract: Ultra-fast aqueous polymerisation of acrylamides by high power visible light direct photoactivation RAFT polymerisation

Back to tab navigation

Supplementary files

Publication details

The article was received on 18 Oct 2017, accepted on 24 Nov 2017 and first published on 27 Nov 2017


Article type: Paper
DOI: 10.1039/C7PY01752A
Citation: Polym. Chem., 2018, Advance Article
  •   Request permissions

    Ultra-fast aqueous polymerisation of acrylamides by high power visible light direct photoactivation RAFT polymerisation

    R. W. Lewis, R. A. Evans, N. Malic, K. Saito and N. R. Cameron, Polym. Chem., 2018, Advance Article , DOI: 10.1039/C7PY01752A

Search articles by author

Spotlight

Advertisements