Optically active photochromic methacrylic polymers with controlled average molecular weight and defined end-groups by atom transfer radical polymerization

Polymer ◽  
2005 ◽  
Vol 46 (8) ◽  
pp. 2424-2432 ◽  
Author(s):  
L. Angiolini ◽  
T. Benelli ◽  
L. Giorgini ◽  
E. Salatelli
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Average Molecular Weight ◽  
Optically Active ◽  
Atom Transfer ◽  
End Groups

Atom transfer radical polymerization of styrene initiated by the novel initiator 2-bromo-2-nitropropane

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Gang Wang ◽  
Xiulin Zhu ◽  
Cheng Zhengping ◽  
Jian Zhu
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Average Molecular Weight ◽  
Monomer Conversion ◽  
Catalyst System ◽  
Chain Extension ◽  
Atom Transfer ◽  
The Novel ◽  
H Nmr

AbstractHeterogeneous atom transfer radical polymerization (ATRP) of styrene initiated by 2-bromo-2-nitropropane in bulk was carried out with CuCl/2,2′-bipyridine as the catalyst. The kinetics was first order in monomer and the numberaverage molecular weight of the polymer increased linearly with monomer conversion, indicating the ‘living’/controlled nature of the polymerization. However, the number-average molecular weight was usually higher than the theoretical one. The nitro group might react with the Cu complex, resulting in insufficient initiation. The amount of catalyst has no effect on the controllability of this catalyst system for the ATRP of styrene. The presence of a halide end group in the obtained polymer was confirmed by both 1H NMR and chain-extension reaction.

scholarly journals In Situ Surface-Initiated Atom-Transfer Radical Polymerization Utilizing the Nonvolatile Nature of Ionic Liquids: A First Attempt

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Ryo Satoh ◽  
Saika Honma ◽  
Hiroyuki Arafune ◽  
Ryo Shomura ◽  
Toshio Kamijo ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Liquid Film ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Silicon Wafer ◽  
Thin Liquid Film ◽  
Average Molecular Weight ◽  
Polymerization Reaction ◽  
Atom Transfer

In this paper, in situ surface-initiated atom-transfer radical polymerization (SI-ATRP) based on both an open and a coated system, without using volatile reagents, was developed to overcome the limited usage of ATRP due to the necessity of sealing. Nonvolatile ionic liquid (IL)-type components were used, specifically N,N-diethyl-N-(2-methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide as the polymerizable monomer and N,N-diethylmethyl(2-methoxyethyl)ammonium bis(trifluoromethylsulfonyl)imide as the polymerization solvent. In the experiment, the reversible-deactivation radical polymerization characteristics are properly ensured in nonvolatile ATRP solution coated on silicon wafer as thin liquid film, to form concentrated polymer brushes (CPBs). The average molecular weight and molecular-weight distribution of the polymer produced in the liquid film and formed on silicon wafer were measured by gel permeation chromatography, which confirms that the polymerization reaction occurred as designed. Furthermore, it is clarified that the surface of the polymer brush synthesized in situ swollen by IL also exhibited low friction characteristics, comparable to that synthesized in a typical immersion process. This paper is the first to establish the effectiveness of in situ preparation for CPBs by using the coating technique.

Effects of a pulsatile magnetic field on the atom transfer radical polymerization of 2-hydroxyethyl methacrylate in methanol

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Stefko B. Iliev ◽  
George S. Georgiev
Keyword(s):  
Magnetic Field ◽  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Average Molecular Weight ◽  
Atom Transfer ◽  
Hydroxyethyl Methacrylate ◽  
Twofold Increase ◽  
The Magnetic Field

Abstract A more than twofold increase in the rate of 2-hydroxyethyl methacrylate atom transfer radical polymerization in methanol at 20°C was observed under the action of a pulsatile magnetic field. At the same time, the average molecular weight of the produced polymers decreased while the polydispersity increased slightly. The results are explained by assuming a shift of the equilibrium from the dormant species to the active propagating radicals under the action of the magnetic field.

Application of novel ionic liquids for reverse atom transfer radical polymerization of methacrylonitrile without any additional ligand

2009 ◽  
Vol 24 (5) ◽  
pp. 1880-1885 ◽  
Author(s):  
Hou Chen ◽  
Yanfeng Meng ◽  
Ying Liang ◽  
Zixuan Lu ◽  
Pingli Lv
Keyword(s):  
Molecular Weight ◽  
Ionic Liquids ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Reaction Rate ◽  
Atom Transfer ◽  
Additional Ligand ◽  
Rapid Reaction ◽  
Living Nature ◽  
First Time

Reverse atom transfer radical polymerization of methacrylonitrile (MAN) initiated by azobisisobutyronitrile (AIBN) was approached for the first time in the absence of any ligand in four novel ionic liquids, 1-methylimidazolium acetate ([mim][AT]), 1-methylimidazolium butyrate ([mim][BT]), 1-methylimidazolium caproate ([mim][CT]), and 1-methylimidazolium heptylate ([mim][HT]). The polymerization in [mim][AT] not only showed the best control of molecular weight and its distribution but also provided a more rapid reaction rate with the ratio of [MAN]:[FeCl3]:[AIBN] at 300:2:1. The block copolymer PMAN-b-PSt was obtained via a conventional ATRP process in [mim][AT] by using the resulting PMAN as a macroinitiator. After simple purification, [mim][AT] and FeCl3 could be easily recycled and reused and had no effect on the living nature of reverse atom transfer radical polymerization of MAN.

scholarly journals Tuning the molecular weight distribution from atom transfer radical polymerization using deep reinforcement learning

2018 ◽  
Vol 3 (3) ◽  
pp. 496-508 ◽  
Author(s):  
Haichen Li ◽  
Christopher R. Collins ◽  
Thomas G. Ribelli ◽  
Krzysztof Matyjaszewski ◽  
Geoffrey J. Gordon ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Reinforcement Learning ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Weight Distribution ◽  
In Silico ◽  
Atom Transfer ◽  
Polymer Molecular Weight ◽  
Molecular Weight Distributions ◽  
Weight Distributions

Combination of deep reinforcement learning and atom transfer radical polymerization gives precise in silico control on polymer molecular weight distributions.

scholarly journals Synthesis of Well-Defined Three-Arm Star-Branched Polystyrene through Arm-First Coupling Approach by Atom Transfer Radical Polymerization

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Syed Shahabuddin ◽  
Fatem Hamime Ismail ◽  
Sharifah Mohamad ◽  
Norazilawati Muhamad Sarih
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Polymeric Chain ◽  
Atom Transfer ◽  
Simple Route ◽  
Coupling Strategy ◽  
Coupling Approach ◽  
Branched Polystyrene ◽  
Williamson Reaction

Here we describe a simple route to synthesize three-arm star-branched polystyrene. Atom transfer radical polymerization technique has been utilized to yield branched polystyrene involving Williamson coupling strategy. Initially a linear polymeric chain of predetermined molecular weight has been synthesized which is further end-functionalized into a primary alkyl bromide moiety, a prime requisition for Williamson reaction. The end-functionalized polymer is then coupled using 1,1,1-tris(4-hydroxyphenyl)ethane, a trifunctional core molecule, to give well-defined triple-arm star-branched polystyrene.

Polystyrene–organoclay nanocomposites produced by in situ activators regenerated by electron transfer for atom transfer radical polymerization

2012 ◽  
Vol 32 (4-5) ◽  
pp. 235-243 ◽  
Author(s):  
Khezrollah Khezri ◽  
Vahid Haddadi-Asl ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Molecular Weight ◽  
Electron Transfer ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Polymer Matrix ◽  
Clay Content ◽  
Xrd Analysis ◽  
Size Exclusion ◽  
Atom Transfer ◽  
Scanning Calorimetry

Abstract A newly developed initiation system, activators regenerated by electron transfer (ARGET), was employed to synthesize polystyrene-organoclay nanocomposites via atom transfer radical polymerization (ATRP). ARGET ATRP was applied since it is carried out at significantly low concentrations of the catalyst and environmentally acceptable reducing agents. Conversion and molecular weight evaluations were performed using gravimetry and size exclusion chromatography (SEC), respectively. According to the findings, addition of clay content resulted in a decrease in conversion and molecular weight of nanocomposites. However, an increase of polydispersity index is observed by increasing nanoclay loading. The living nature of the polymerization is revealed by 1H NMR spectroscopy and extracted data from the SEC traces. X-ray diffraction (XRD) analysis shows that organoclay layers are disordered and delaminated in the polymer matrix and exfoliated morphology is obtained. Thermogravimetric analysis (TGA) shows that thermal stability of the nanocomposites is higher than the neat polystyrene. A decrease in glass transition temperature of the samples by increasing organoclay content is observed by differential scanning calorimetry (DSC). Transmission electron microscopy (TEM) reveals that clay layers are partially exfoliated in the polymer matrix containing 2 wt% of organomodified montmorillonite (PSON 2) and a dispersion of partially exfoliated clay stacks is formed.

Sign in / Sign up

Export Citation Format

Share Document