Nitroxide-Mediated Polymerization of 2-(Diethylamino)ethyl Methacrylate (DEAEMA) in Water

2014 ◽  
Vol 48 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Ali Darabi ◽  
Abbas Rezaee Shirin-Abadi ◽  
Philip G. Jessop ◽  
Michael F. Cunningham
2021 ◽  
pp. 2100011
Author(s):  
Alexander T. Fritz ◽  
Jaime C. Cazotti ◽  
Omar Garcia‐Valdez ◽  
Niels M. B. Smeets ◽  
Marc A. Dubé ◽  
...  

Author(s):  
Matthieu P. J. Miclotte ◽  
Stefan B. Lawrenson ◽  
Spyridon Varlas ◽  
Bilal Rashid ◽  
Emma Chapman ◽  
...  

2021 ◽  
Author(s):  
Valdomiro V. de Souza ◽  
Gustavo P. B. Carretero ◽  
Phelipe A. M. Vitale ◽  
Íris Todeschini ◽  
Paloma O. Kotani ◽  
...  

2021 ◽  
pp. 096739112110245
Author(s):  
Amrita Sharma ◽  
PP Pande

It has been observed that acrylate monomers are very difficult to polymerize with the low cost nitroxide catalyst 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO). Therefore, costly acyclic nitroxides such as N-tert-butyl-N-(1-diethylphosphono-2,2-dimethyl)-N-oxyl, (SG1), 2,2,5-Trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) and TIPNO derivatives have to be used for the polymerization of the acrylic acid derivatives. There are very few reports on the use of TEMPO-derivatives toward the polymerization of n-butyl acrylate. Generally different reducing agents viz. glucose, ascorbic acid, hydroxyacetone etc. have been used to destroy excess TEMPO during the polymerization reaction. The acrylate polymerizations fail in the presence of TEMPO due to the strong C–O bond formed between the acrylate chain end and nitroxide. To the best of our knowledge, no literature report is available on the use of TEMPO without reducing agent or high temperature initiators, toward the polymerization of n-butyl acrylate. The present study has been carried out with a view to re-examine the application of low cost nitroxide TEMPO, so that it can be utilized towards the polymerization of acrylate monomers (e.g. n-butyl acrylate). We have been able to polymerize n-butyl acrylate using the nitroxide TEMPO as initiator (via a macroinitiator). In this synthesis, a polystyrene macroinitiator was synthesized in the first step from TEMPO, after this TEMPO end-capped styrene macroinitiator (PSt-TEMPO) is used to polymerize n-butyl acrylate monomer. The amount of macroinitiator taken was varied from 0.05% to 50% by weight of n-butyl acrylate monomer. The polymerization was carried out at 120°C by bulk polymerization method. The experimental findings showed a gradual increase in molecular weight of the polymer formed and decrease in the polydispersity index (PDI) with increase in amount of PSt-TEMPO macroinitiator taken. In all experiments conversion was more than 80%. These results indicate that the polymerization takes place through controlled polymerization process. Effect of different solvents on polymerization has also been investigated. In the following experiments TEMPO capped styrene has been used as macroinitiator leading to the successful synthesis of poly n-Butyl acrylate. It has been found that styrene macroinitiator is highly efficient for the nitroxide mediated polymerization, even in very small concentration for the synthesis of poly n-butyl acrylate. High concentration of macroinitiator results in the formation of block copolymers of polystyrene and poly ( n-butyl acrylate) viz. polystyrene-block-poly-( n-butyl acrylate). The use of TEMPO toward controlled polymerization is of much importance, because it is the nitroxide commercially available at the lowest cost.


Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 59
Author(s):  
Abeer M. Beagan ◽  
Ahlam A. Alghamdi ◽  
Shatha S. Lahmadi ◽  
Majed A. Halwani ◽  
Mohammed S. Almeataq ◽  
...  

Currently, chemotherapy is an important method for the treatment of various cancers. Nevertheless, it has many limitations, such as poor tumour selectivity and multi-drug resistance. It is necessary to improve this treatment method by incorporating a targeted drug delivery system aimed to reduce side effects and drug resistance. The present work aims to develop pH-sensitive nanocarriers containing magnetic mesoporous silica nanoparticles (MMSNs) coated with pH-responsive polymers for tumour-targeted drug delivery via the folate receptor. 2-Diethyl amino ethyl methacrylate (DEAEMA) was successfully grafted on MMSNs via surface initiated ARGET atom transfer radical polymerization (ATRP), with an average particle size of 180 nm. The end groups of poly (2-(diethylamino)ethyl methacrylate) (PDEAEMA) brushes were converted to amines, followed by a covalent bond with folic acid (FA) as a targeting agent. FA conjugated to the nanoparticle surface was confirmed by X-ray photoelectron spectroscopy (XPS). pH-Responsive behavior of PDEAEMA brushes was investigated by Dynamic Light Scattering (DLS). The nanoparticles average diameters ranged from ca. 350 nm in basic media to ca. 650 in acidic solution. Multifunctional pH-sensitive magnetic mesoporous nanoparticles were loaded with an anti-cancer drug (Doxorubicin) to investigate their capacity and long-circulation time. In a cumulative release pattern, doxorubicin (DOX) release from nano-systems was ca. 20% when the particle exposed to acidic media, compared to ca. 5% in basic media. The nano-systems have excellent biocompatibility and are minimally toxic when exposed to MCF-7, and -MCF-7 ADR cells.


2017 ◽  
Vol 19 (34) ◽  
pp. 22678-22683 ◽  
Author(s):  
Ganna Gryn’ova ◽  
Leesa M. Smith ◽  
Michelle L. Coote

In the present work we use accurate quantum chemistry to evaluate several known and novel nitroxides bearing acid–base groups as pH-switchable control agents for room temperature NMP.


Sign in / Sign up

Export Citation Format

Share Document