Using controlled radical polymerization to confirm the lower critical solution temperature of an N‐(alkoxyalkyl) acrylamide polymer in aqueous solution

Abstract

NANOCOMPOSITE On page 3506, Adriana C. Pinheiro, Adriana C. A. Casagrande, and Osvaldo L. Casa-grande, Jr., report linear low density polyethylene (LLDPE) nanocomposites containing different types of nanofiller (TiO 2 , MWCNT, expanded graphite, and boehmite) prepared with a tandem catalyst system composed of {Tp Ms }NiCl and Cp 2 ZrCl 2 with only ethylene as the monomer. Among the nanofillers utilized, carbon nanotubes and boehmite can nucleate LLDPE crystallization, as indicated by increased crystallization temperature. Furthermore, the presence of these nanofillers in the LLDPE matrix results in substantial improvement of the storage modulus as compared to neat LLDPE. The TEM images of LLDPE nanocomposites containing boehmite and MWCNT reveal homogeneous dispersion of these nanofillers into the LLDPE matrix. report on nanoparticles obtained after complexa-tion of Ru(NH 3) 3 Cl 3 with hydroxyl groups of dendritic copolymers of tert-butyl-glycidyl-ether and glycidol using silver tetrafluoroborate as a dechlorination agent. Visualization is performed by cryogenic transmission electron microscopy using a Libra 120 Zeiss microscope , operated at an acceleration voltage of 120 kV, at the Leibniz Institute of Polymer Research Dresden.

Controlled Synthesis and Degradation of Poly(N-(isobutoxymethyl) acrylamide) Homopolymers and Block Copolymers

“…Polymers that undergo a thermally induced phase separation, such as a lower critical solution temperature (LCST), have recently found application in as drug delivery vehicles, antibacterial materials, latex particle coatings, dielectrics, and thermally curable thin films as part of systems containing conductive materials . Several N‐substituted poly(acrylamide)s experience sharp and biologically relevant LCSTs around 30–60 °C . The properties of the polymer, such as molecular weight distribution, copolymer composition, and molecular architecture, have an impact on the final polymer's thermoresponsiveness .…”

“…Several N‐substituted poly(acrylamide)s experience sharp and biologically relevant LCSTs around 30–60 °C . The properties of the polymer, such as molecular weight distribution, copolymer composition, and molecular architecture, have an impact on the final polymer's thermoresponsiveness . Traditionally, these well‐defined molecular architectures were only achievable by living polymerization techniques, such as ionic polymerization .…”

“…[22,27] NMP is often desirable over ATRP, where transition metal catalysts can still be present in final polymers [22] and RAFT, where odorous sulfur-based chain transfer agents often have to be removed. [17] NMP is also an industrially robust technique often only requiring a single unimolecular initiator to initiate and control the polymerization as well as a simple filtration or evaporation to separate the monomer from the pure polymer, unlike other techniques that require column chromatography to remove catalysts or other unwanted side products. [28,29] The original NMP alkoxyamine The homopolymerization of the water-insoluble N-(isobutoxymethyl)acrylamide (IBMA) is investigated for the first time by nitroxide-mediated polymerization.…”

Stimuli-responsive 4-acryloylmorpholine/4-acryloylpiperidine copolymers via nitroxide mediated polymerization

“…Traditionally, NMP was restricted to the polymerization of styrenic monomers using 2,2,6,6‐tetramethyl‐piperidine 1‐oxyl initiator (TEMPO) . NMP's recent development has been accelerated by the development of initiators based on alkoxyamines such as N ‐tert‐butyl‐ N ‐[1‐diethylphosphono‐(2,2‐dimethylpropyl)]nitroxide (SG1) and 2,2,5‐trimethyl‐4‐phenyl‐3‐azahexane‐3‐nitroxide (TIPNO), which have allowed the controlled polymerization of a wider range of monomers including acrylates, acrylamides, and methacrylates (with a small addition of “controlling” comonomers) . NMP controls the radical concentration for a significant period of the polymerization, thereby minimizing irreversible termination reactions.…”

“…One of the most studied poly(acrylamide)s is N‐ isopropylacrylamide (NIPAM), the homopolymer of which exhibits LCST near 32 °C and makes it a perfect candidate for biological applications . Some other thermoresponsive poly(acrylamides) that have been studied are N , N ‐diethylacrylamide, N ‐ethylacrylamide, ( N ‐(3‐methoxypropyl) acrylamide, N‐n ‐propylacrylamide, N,N ‐ethylmethylacrylamide, to name a few. An important sub‐class of poly(acrylamides) are those based on a ring motif such as pyrrolidone, piperidine, and morpholine .…”