Haloalkane C−X Bond Activation by a Ruthenium(II) Complex:  X-ray Characterization of a Ruthenium(III) Intermediate Species in the Atom Transfer Radical Polymerization of Methyl Methacrylate

2000 ◽  
Vol 19 (3) ◽  
pp. 361-364 ◽  
Author(s):  
Ignacio del Río ◽  
Gerard van Koten ◽  
Martin Lutz ◽  
Anthony L. Spek
Keyword(s):  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Bond Activation ◽  
Atom Transfer ◽  
Intermediate Species ◽  
X Ray

Characterization of electrospun polylactide nanofibers modified via atom transfer radical polymerization

2020 ◽  
pp. 152808372093038 ◽  
Author(s):  
Muhammad Mushtaq ◽  
Rahim Jindani ◽  
Amjad Farooq ◽  
Xin Li ◽  
Hina Saba ◽  
...  
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Photoelectron Spectroscopy ◽  
Polymer Chains ◽  
Surface Grafting ◽  
Atom Transfer ◽  
X Ray ◽  
Polymerization Method ◽  
Scanning Electron

Polylactic acid-based membranes received considerable attention due to its novel biocompatibility, renewability, and biodegradability. In this study, PLA electrospun nanofibrous membrane was prepared and 2-dimethylaminoethyl methacrylate (DMAEMA) was used as a monomer for surface grafting of polymer chains via the atom transfer radical polymerization method. Then the PLA nanofibers were quaternized by using bromoethane. The characterization of poly(DMAEMA) graft PLA nanofiber (poly(DMAEMA)-g-PLA) membranes was done by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and energy dispersive X-ray spectroscopy. The results showed that the diameter of PLA nanofibers increased 15% as the concentration increased from 10% to 12% and then increased 23% as the concentration of PLA solution increased from 10% to 15%. But the regularity of average diameters is best achieved at 12% concentration.

scholarly journals Grafting Poly(Methyl Methacrylate) (PMMA) from Cork via Atom Transfer Radical Polymerization (ATRP) towards Higher Quality of Three-Dimensional (3D) Printed PMMA/Cork-g-PMMA Materials

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1867
Author(s):  
Paula S. S. Lacerda ◽  
Nuno Gama ◽  
Carmen S. R. Freire ◽  
Armando J. D. Silvestre ◽  
Ana Barros-Timmons
Keyword(s):  
Solid State ◽  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Three Dimensional ◽  
Flow Index ◽  
Atom Transfer ◽  
X Ray ◽  
Poly Methyl Methacrylate ◽  
3D Printed

Cork is a unique material and its by-products are attracting an ever-growing interest for preparing new materials in an attempt to extend the outstanding properties of cork toward innovative and high value applications. Yet, the miscibility of cork particles with thermoplastic matrices is not easy due to its low density and surface properties. Here, cork is functionalized with poly(methyl methacrylate) (PMMA) via atom transfer radical polymerization (ATRP) to yield cork grafted with PMMA chains particles (cork-g-PMMA). Both the ATRP macroinitiator and the cork-g-PMMA obtained are fully characterized by Fourier-transform infrared spectroscopy (FT-IR), 13C cross-polarized magic-angle spinning solid-state nuclear magnetic resonance (13C CP/MAS solid state NMR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) and thermogravimetric analyses (TGA). The functionalized cork particles are then blended with commercial PMMA to afford cork-g-PMMA/PMMA. To compare, cork also is mixed with PMMA and the ensuing cork/PMMA sample and its morphology, thermal, and mechanical properties are compared with those of cork-g-PMMA/PMMA and commercial PMMA. The cork surface modification via ATRP of the methyl methacrylate (MMA) yields better dispersion in the matrix. Consequently, a blend with enhanced mechanical performance, higher thermal stability, and a higher melt flow index (MFI) is obtained when compared to the blend prepared using unmodified particles. The similarity of the MFI of cork-g-PMMA/PMMA to that of PMMA suggests good printability. Indeed, a three-dimensional (3D) printed specimen is obtained confirming that grafting using ATRP is a promising route for the preparation of high quality 3D printed products.

Evaluation of ruthenium-based complexes for the controlled radical polymerization of vinyl monomers

2001 ◽  
Vol 79 (5-6) ◽  
pp. 529-535 ◽  
Author(s):  
François Simal ◽  
Dominique Jan ◽  
Lionel Delaude ◽  
Albert Demonceau ◽  
Marie-Rose Spirlet ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Atom Transfer Radical Polymerization ◽  
Key Words ◽  
Radical Polymerization ◽  
Homogeneous Catalysis ◽  
Kinetic Data ◽  
Controlled Radical Polymerization ◽  
Vinyl Monomers ◽  
Atom Transfer ◽  
X Ray

New complexes of the type RuCl2(p-cymene)L where the ligand L is either a phosphine or a stable triazolinylidene carbene have been tested and compared to the Grubbs' benzylidene complex RuCl2(=CHPh)(PCy3)2 as catalyst precursors for the controlled atom transfer radical polymerization (ATRP) of methyl methacrylate and of various para-substituted styrenes. Kinetic data and Hammett ρ constants are reported, as well as the X-ray structure of the ortho-metallated triazolinylidene-ruthenium(II) complex RuCl(p-cymene)[1,2-phenylene[3,4-diphenyl-1H-1,2,4-triazol-1-yl-5(4H)-ylidene]].Key words: ruthenium, carbene, chelate complex, homogeneous catalysis, atom transfer radical polymerization.

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