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Polymethacrylamide—An underrated and easily accessible upper critical solution temperature polymer: Green synthesis via photoiniferter reversible addition–fragmentation chain transfer polymerization and analysis of solution behavior in water/ethanol mixtures
Author(s) -
Eckert Tilman,
Abetz Volker
Publication year - 2020
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20200566
Subject(s) - upper critical solution temperature , chain transfer , polymerization , polymer , polymer chemistry , chemical engineering , mass fraction , hydrolysis , lower critical solution temperature , chemistry , dynamic light scattering , materials science , radical polymerization , organic chemistry , nanoparticle , nanotechnology , copolymer , engineering
Within the group of stimuli‐responsive, “smart” materials, upper critical solution temperature (UCST) polymers remain sparsely investigated. Thus, this work focusses on a vastly ignored UCST polymer: polymethacrylamide (PMAAm). A cost‐efficient photoiniferter reversible addition–fragmentation chain transfer (RAFT) polymerization yielding narrowly dispersed ( Đ < 1.1) PMAAm is presented. This PMAAm exhibits highly thermoreversible UCST‐type phase transitions (PT) in water/ethanol mixtures (ethanol content: 17–35 wt%) which are investigated via temperature dependent dynamic light scattering (DLS). Apart from the ethanol content, the PT temperature is affected by polymer mass fraction and chain length and varies between 10–80 °C depending on the three mentioned parameters. Lastly, PMAAm's propensity towards amide hydrolysis and concomitant PT‐suppression is investigated. Below temperatures of 40 °C, PMAAm solutions show no sign of amide hydrolysis for at least three days, however, if heated to 70 °C, the thermoresponsiveness gradually degrades within hours.