Synthesis of Novel Size Exclusion Chromatography Support by Surface Initiated Aqueous Atom Transfer Radical Polymerization

Langmuir ◽  
2007 ◽  
Vol 23 (23) ◽  
pp. 11791-11803 ◽  
Author(s):  
Bryan R. Coad ◽  
Jayachandran N. Kizhakkedathu ◽  
Charles A. Haynes ◽  
Donald E. Brooks
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Size Exclusion Chromatography ◽  
Size Exclusion ◽  
Atom Transfer ◽  
Exclusion Chromatography

scholarly journals Atom Transfer Radical Polymerization of Styrene and Acrylates: Effects of Catalyst, Ligand, Solvent, and Initiator

2021 ◽  
Vol 13 (3) ◽  
pp. 999-1010
Author(s):  
M. W. Ullah ◽  
N. Haraguchi ◽  
M. A. Ali ◽  
M. R. Alam ◽  
M. Mahiuddin ◽  
...  
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
1H Nmr Spectroscopy ◽  
Diphenyl Ether ◽  
Benzyl Bromide ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Butyl Methacrylate ◽  
Atom Transfer ◽  
Exclusion Chromatography

Well-defined polystyrenes were successfully prepared by the CuX/(dN)bpy or CuX/ PMDETA catalyzed atom transfer radical polymerization of styrene using 1-phenylethyl bromide (1-PEBr) or benzyl bromide (BnBr) as initiators. We found that the CuX/PMDETA catalyzed ATRP of styrene proceeded faster than CuX/(dN)bpy catalyzed counterpart in bulk, diphenyl ether (DPE) and anisole. Using CuX/(dN)bpy catalyst, well-defined polystyrenes were obtained with good chain-end functionalities and low polydispersity (Mw/Mn <1.5) compared to CuX/PMDETA catalyst. The CuBr/PMDETA catalyzed ATRP of n-butyl acrylate (nBA), n-butyl methacrylate (nBMA), and tert-butyl methacrylate (tBMA) were also proceeded in a controlled manner. The molecular structure and molecular weight of polymers were determined by proton nuclear magnetic resonance (1H NMR) spectroscopy and size exclusion chromatography (SEC), respectively.

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.

scholarly journals Synthesis of sequence-defined acrylate oligomers via photo-induced copper-mediated radical monomer insertions

2015 ◽  
Vol 6 (10) ◽  
pp. 5753-5761 ◽  
Author(s):  
Joke Vandenbergh ◽  
Gunter Reekmans ◽  
Peter Adriaensens ◽  
Thomas Junkers
Keyword(s):  
Radical Polymerization ◽  
Size Exclusion Chromatography ◽  
Single Unit ◽  
Size Exclusion ◽  
Insertion Reactions ◽  
Exclusion Chromatography

Photo-induced copper-mediated radical polymerization is used to synthesize monodisperse sequence defined acrylate oligomers via consecutive single unit monomer insertion reactions and intermediate purification of the compounds by column or preparative recycling size exclusion chromatography.

Synthesis of well-defined clay encapsulated poly(styrene-co-butyl acrylate) nanocomposite latexes via reverse atom transfer radical polymerization in miniemulsion

2012 ◽  
Vol 32 (2) ◽  
Author(s):  
Khezrollah Khezri ◽  
Vahid Haddadi-Asl ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Electron Microscopy ◽  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Butyl Acrylate ◽  
Size Exclusion ◽  
Spherical Particles ◽  
Atom Transfer ◽  
Sem Images ◽  
Nanoclay Content

Abstract Well-defined poly(styrene-co-butyl acrylate) nanocomposite latexes were synthesized via reverse atom transfer radical polymerization (RATRP) in miniemulsion. Successful RATRP was carried out by using a hydrophobic ligand of 4,4’-dinonyl-2,2’-bipyridine (dNbpy) and a cationic surfactant of cetyltrimethylammonium bromide (CTAB). Dynamic light scattering (DLS) results show that droplets and particles with sizes in the range of about 170 nm were formed. Overall, conversion and molecular weight evaluation were performed by using gravimetry and size exclusion chromatography (SEC), respectively. Increasing nanoclay loading resulted in an increase in the conversion and molecular weight of the nanocomposites. However, polydispersity index (PDI) values increased by adding nanoclay content. Thermal stability of all the nanocomposites improved in comparison with the neat copolymer, according to the thermogravimetric analysis (TGA) results. Differential scanning calorimetry (DSC) results showed that the glass transition temperature (Tg) increased by increasing nanoclay content. Scanning electron microscopy (SEM) images of the nanocomposite with 1 wt% of nanoclay showed a monodisperse distribution of spherical particles, with sizes in the range of approximately 170 nm, as confirmed by the DLS data. Similarly, transmission electron microscopy (TEM) images show that clay layers are delaminated and well dispersed in the matrix of nanocomposite with 1 wt% clay content.

scholarly journals Αυτοοργάνωση αμφίφιλων συμπολυμερών σε εκλεκτικούς διαλύτες

2017 ◽  
Author(s):  
Μαργαρίτα Δρούλια
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Radical Polymerization ◽  
Size Exclusion Chromatography ◽  
1H Nmr ◽  
Size Exclusion ◽  
Scanning Calorimetry ◽  
Exclusion Chromatography ◽  
Nuclear Magnetic

Στην παρούσα Διδακτορική διατριβή συντέθηκαν επιτυχώς δισυσταδικά συμπολυμερή πολυαιθυλενοξειδίου-b-πολυ(μεθακρυλικού φερροκενυλοκαρβοξυ-2-αιθυλεστέρα) (PEO-b-PMAEFc), δισυσταδικά συμπολυμερή πολυαιθυλενοξειδίου-b-πολυ(μεθακρυλικού βενζυλεστέρα) (PEO-b-PBnMA) και τέλος τρισυσταδικά συμπολυμερή πολυ(μεθακρυλικού βενζυλεστέρα)-b-πολυαιθυλενοξειδίου-b-πολυ(μεθακρυλικού βενζυλεστέρα) (PBnMA-b-PEO-b- PBnMA) μέσω ριζικού πολυμερισμού μεταφοράς ατόμου (Atom Tranfer Radical Polymerization, ATRP).Τα παραπάνω συμπολυμερή χαρακτηρίστηκαν με Χρωματογραφία Αποκλεισμού Μεγεθών (Size Exclusion Chromatography, SEC) και Φασματοσκοπία Πυρηνικού Μαγνητικού Συντονισμού (Nuclear Magnetic Resonanse, 1H-NMR). Έτσι προσδιορίστηκαν τα μέσα μοριακά βάρη, η κατανομή των μοριακών βαρών και η σύσταση των συμπολυμερών. Μέσω της Θερμοσταθμικής Ανάλυσης (Thermogravimetric Analysis, TGA) και της Διαφορικής θερμιδομετρίας Σάρωσης (Differential Scanning Calorimetry, DSC) μελετήθηκε η θερμική τους αποικοδόμηση και προσδιορίστηκαν οι θερμοκρασίες υαλώδους μετάπτωσης και οι θερμοκρασίες τήξης των δισυσταδικών και τρισυσταδικών συμπολυμερών σε σχέση με τα αντίστοιχα ομοπολυμερή. Τέλος μελετήθηκε η αυτοοργάνωση των παραπάνω συμπολυμερών σε εκλεκτικούς διαλύτες (νερό και ακετονιτρίλιο) ως προς τη μια συστάδα (πολυαιθυλενοξείδιο) μέσω της δυναμικής σκέδασης φωτός και επιβεβαιώθηκε ο σχηματισμός μικκυλίων και μικκυλιακών συσσωματωμάτων. Ακολούθως προσδιορίστηκε η υδροδυναμική ακτίνα και ο συντελεστής άπειρης αραιώσης των παραπάνω μικκυλιακών δομών.

Reverse Atom Transfer Radical Polymerization of Styrene in the Presence of Functionalized Silica Aerogel Nanoparticles

2016 ◽  
Vol 230 (10) ◽  
Author(s):  
Khezrollah Khezri ◽  
Hossein Mahdavi
Keyword(s):  
Molecular Weight ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Silica Aerogel ◽  
Structural Characteristics ◽  
Nitrogen Adsorption ◽  
Size Exclusion ◽  
Atom Transfer ◽  
Functionalized Nanoparticles ◽  
Morphological Studies

AbstractPristine silica aerogel nanoparticles surface was functionalized with 3-(trimethoxysilyl)propyl methacrylate (MPS). Then, the resultant functionalized nanoparticles were used in grafting through polymerization of styrene by reverse initiation technique for atom transfer radical polymerization. Nitrogen adsorption/desorption isotherm is applied to examine surface area and structural characteristics of the synthesized nanoparticles. Evaluation of size distribution and morphological studies were also performed by scanning and transmission electron microscopy. Conversion and molecular weight determinations were carried out using gas and size exclusion chromatography respectively. Addition of MPS-functionalized nanoparticles by 3 wt % results in a decrease of conversion from 98 to 81%. Molecular weight (

scholarly journals End Group Stability of Atom Transfer Radical Polymerization (ATRP)-Synthesized Poly(N-isopropylacrylamide): Perspectives for Diblock Copolymer Synthesis

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 678 ◽  
Author(s):  
Herberg ◽  
Yu ◽  
Kuckling
Keyword(s):  
Mass Spectrometry ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Size Exclusion ◽  
Polymerization Process ◽  
Atom Transfer ◽  
Group Stability ◽  
Catalyst Complex ◽  
End Groups ◽  
End Group

Studies on the end group stability of poly(N-isopropylacrylamide) during the atom transfer radical polymerization (ATRP) process are presented. Polymerization of N-isopropylacrylamide was conducted in different solvents using a copper(I) chloride/Me6Tren catalyst complex. The influence of the ATRP solvent as well as the polymer purification process on the end group stability was investigated. For the first time, mass spectrometry results clearly underline the loss of ω end groups via an intramolecular cyclization reaction. Furthermore, an ATRP system based on a copper(I) bromide/Me6Tren catalyst complex was introduced, that showed not only good control over the polymerization process, but also provided the opportunity of block copolymerization of N-isopropylacrylamide with acrylates and other N-substituted acrylamides. The polymers were characterized using 1H-NMR spectroscopy and size exclusion chromatography. Polymer end groups were determined via ESI-TOF mass spectrometry enhanced by ion mobility separation (IMS).

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