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

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).

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Aurore Olivier ◽  
Franck Meyer ◽  
Jean-Marie Raquez ◽  
Philippe Dubois

Abstract This paper report the synthesis of binary-patterned brushes, combining two distinctive surface initiated-polymerizations (SIP) on the basis of different propagating species: the SI Ring Opening Polymerization (ROP) of L-Lactide (LLA) and SI atom transfer radical polymerization (ATRP) of N,N’-dimethylaminoethyl methacrylate (DMAEMA) on gold surface. First of all, a careful study of surfaceinitiated ROP of L-Lactide from hydroxyl end-group of thiol monolayer on gold surface as catalyzed by metal-free catalyst was carried out. The PLLA brushes synthesis was evaluated using two types of thiol monolayer and revealed the influence of ROP initiator chain length on the final thickness of the PLLA film. Combining the soft lithographic technique, microcontact printing, and the liquid phase deposition, the deposition onto specific micro-domains of both initiators was performed. The growth of PDMAEMA brushes and PLLA brushes was conducted by successive ATRP and ROP.


2013 ◽  
Vol 364 ◽  
pp. 679-683
Author(s):  
Chang Hao Yan ◽  
Zhi Jiao Zhang ◽  
Hai Yan Chen ◽  
Zhong Yi Xie ◽  
Ting Zhu ◽  
...  

The polystyrene with end group of Br was synthesized by using MBrP as the initiator, CuBr/ PMDETA as the catalyst system according to atom transfer radical polymerization (ATRP). The effect of reaction temperature was studied and the system was confirmed as the active polymerization. Then PS-Br and CuBr/ PMDETA were respectively used as macroinitiator and catalyst to polymerize tBMA according to atom transfer radical polymerization (ATRP). The structure of the product was characterized by GPCFTIR1H-NMR. The amphiphilic block copolymer was obtained after hydrolysis. And the honeycomb porous film was prepared by PS-b-PMAA through using breath figure method.


2012 ◽  
Vol 32 (4-5) ◽  
pp. 235-243 ◽  
Author(s):  
Khezrollah Khezri ◽  
Vahid Haddadi-Asl ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi

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.


2005 ◽  
Vol 41 (11) ◽  
pp. 2742-2752 ◽  
Author(s):  
Ren Qiang ◽  
Jiang Bibiao ◽  
Zhang Dongliang ◽  
Yu Qiang ◽  
Fang Jianbo ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3030 ◽  
Author(s):  
Monika Flejszar ◽  
Paweł Chmielarz

Surface-initiated atom transfer radical polymerization (SI-ATRP) is a powerful tool that allows for the synthesis of organic–inorganic hybrid nanomaterials with high potential applications in many disciplines. This review presents synthetic achievements and modifications of nanoparticles via SI-ATRP described in literature last decade. The work mainly focuses on the research development of silica, gold and iron polymer-grafted nanoparticles as well as nature-based materials like nanocellulose. Moreover, typical single examples of nanoparticles modification, i.e., ZnO, are presented. The organic–inorganic hybrid systems received according to the reversible deactivation radical polymerization (RDRP) approach with drastically reduced catalyst complex concentration indicate a wide range of applications of materials including biomedicine and microelectronic devices.


2013 ◽  
Vol 49 (8) ◽  
pp. 2344-2355 ◽  
Author(s):  
Dagmar R. D’hooge ◽  
Magali Vachaudez ◽  
Florian J. Stadler ◽  
Marie-Françoise Reyniers ◽  
Olivier Coulembier ◽  
...  

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