Catalysis with palladium colloids supported in poly(acrylic acid)-grafted polyethylene and polystyrene

2006 ◽  
Vol 84 (10) ◽  
pp. 1343-1350 ◽  
Author(s):  
David E Bergbreiter ◽  
Andrew Kippenberger ◽  
Zhenqi Zhong
Keyword(s):  
Acrylic Acid ◽  
Substitution Reaction ◽  
Supported Catalysts ◽  
Product Formation ◽  
Allylic Substitution ◽  
Heck Reactions ◽  
Substitution Reactions ◽  
Substitution Chemistry ◽  
Polyethylene Powder ◽  
Poly Acrylic Acid

Grafts of poly(acrylic acid) on polyethylene powder (PE-g-PAA) or polystyrene (PS-g-PAA) can be used to support Pd(0) crystallites that function like a homogeneous Pd(0) catalyst in some reactions. These Pd–PE-g-PAA catalysts were active in allylic substitution reactions in the presence of added phosphine ligand. A catalyst analogous to the Pd–PE-g-PAA powder catalyst on polystyrene (Pd–PS-g-PAA) was similarly active for allylic substitution and could also be used in Heck reactions at 80–100 °C in N,N-dimethylacetamide (DMA). Analysis of the product solutions for Pd leachate and a correlation of the Pd leaching with product formation in the allylic substitution chemistry for both types of catalysts suggests that the active catalysts in these reactions are leached from the support. In the case of the allylic substitution reaction, external triphenylphosphine and substrate together are required for the chemistry and Pd leaching.Key words: catalysis, palladium, allylic substitution, grafted polystyrene, supported catalysts.

Palladium catalysed heck reactions and allylic substitution reactions using glass bead technology

1997 ◽  
Vol 38 (24) ◽  
pp. 4319-4322 ◽  
Author(s):  
Louise Tonks ◽  
Michael S Anson ◽  
Klaus Hellgardt ◽  
Amin R Mirza ◽  
David F Thompson ◽  
...  
Keyword(s):  
Glass Bead ◽  
Allylic Substitution ◽  
Heck Reactions ◽  
Substitution Reactions

ChemInform Abstract: Palladium-Catalyzed Heck Reactions and Allylic Substitution Reactions Using Glass Bead Technology.

ChemInform ◽  
2010 ◽  
Vol 28 (38) ◽  
pp. no-no
Author(s):  
L. TONKS ◽  
M. S. ANSON ◽  
K. HELLGARDT ◽  
A. R. MIRZA ◽  
D. F. THOMPSON ◽  
...  
Keyword(s):  
Glass Bead ◽  
Allylic Substitution ◽  
Heck Reactions ◽  
Substitution Reactions ◽  
Palladium Catalyzed

Soft ionic liquid based resistive memory characteristics in a two terminal discrete polydimethylsiloxane cylindrical microchannel

2020 ◽  
Vol 8 (38) ◽  
pp. 13368-13374
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Jinho Bae
Keyword(s):  
Ionic Liquid ◽  
Acrylic Acid ◽  
Sodium Hydroxide ◽  
Sodium Salt ◽  
Resistive Memory ◽  
Cylindrical Microchannel ◽  
Memory Characteristics ◽  
Poly Acrylic Acid

This paper proposes a novel soft ionic liquid (IL) electrically functional device that displays resistive memory characteristics using poly(acrylic acid) partial sodium salt (PAA-Na+:H2O) solution gel and sodium hydroxide (NaOH) in a thin polydimethylsiloxane (PDMS) cylindrical microchannel.

Reactions of macroions with ester and carboxylic groups of polymers

1987 ◽  
Vol 52 (9) ◽  
pp. 2194-2203
Author(s):  
Miloslav Kučera ◽  
Dušan Kimmer ◽  
Karla Majerová ◽  
Josef Majer
Keyword(s):  
Maleic Anhydride ◽  
Acrylic Acid ◽  
Methyl Methacrylate ◽  
Bond Formation ◽  
Covalent Bond ◽  
The Other ◽  
Poly Methyl Methacrylate ◽  
Other Hand ◽  
Carboxylic Groups ◽  
Poly Acrylic Acid

In the reaction of dianions with poly(methyl methacrylate), only an insignificant amount of insoluble crosslinked product is obtained. If, however, the concentration of grafting dianions approaches that of ester groups, the amount of poly(methyl methacrylate) which may thus be crosslinked becomes quite significant. Dications, too, can bring about crosslinking of only an insignificant number of poly(methyl methacrylate) chains. Carboxylic groups in poly(acrylic acid) react with dianions and dications in an anhydrous medium similarly to ester groups. On the other hand, in the presence of a cocatalytic amount of water dications are more readily bound to carboxylic groups, forming a covalent bond. The relatively highest efficiency was observed in the bond formation between dication and the poly[styrene-alt-(maleic anhydride)], both in an anhydrous medium and in the presence of H2O.

Fabrication and Characterization of Chitosan-Poly(acrylic acid) Magnetic Nanospheres

2009 ◽  
Vol 9 (2) ◽  
pp. 1287-1290 ◽  
Author(s):  
Yuqing Ge ◽  
Song Zhang ◽  
Shiying He ◽  
Yu Zhang ◽  
Ning Gu
Keyword(s):  
Acrylic Acid ◽  
Magnetic Nanospheres ◽  
Fabrication And Characterization ◽  
Poly Acrylic Acid

Synthesis, characterization, and their some chemical and biological properties of PVA/PAA/nPS hydrogel nanocomposites: Hydrogel and wound dressing

2020 ◽  
Vol 35 (3) ◽  
pp. 203-215
Author(s):  
Mehmet Emin Diken ◽  
Berna Koçer Kizilduman ◽  
Begümhan Yilmaz Kardaş ◽  
Enes Emre Doğan ◽  
Mehmet Doğan ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Acrylic Acid ◽  
Infrared Spectra ◽  
Vinyl Alcohol ◽  
Fourier Transform Infrared ◽  
Poly Vinyl Alcohol ◽  
Seed Particles ◽  
Fourier Transform Infrared Spectra ◽  
Hydrogel Nanocomposites ◽  
Poly Acrylic Acid

The nanocomposite hydrogels were prepared by dispersing of the nanopomegranate seed particles into poly(vinyl alcohol)/poly(acrylic acid) blend matrix in an aqueous medium by the solvent casting method. These hydrogels were characterized using scanning electron microscopy, Fourier transform infrared spectra, differential scanning calorimetry, and optical contact angle instruments. The nanopomegranate seed, blend, and hydrogel nanocomposites were tested for microbial activity. In addition, cytocompatibilities of these blend and hydrogel nanocomposites/composites were tested on human lymphocyte with in vitro MTS cell viability assays. Fourier transform infrared spectra revealed that esterification reaction took place among functional groups in the structure of poly(vinyl alcohol) and poly(acrylic acid). The hydrophilic properties of all hydrogels decreased with increasing nanopomegranate seed content. The mean diameters of the nanopomegranate seed particles were about 88 nm. Nanopomegranate seed particles demonstrated antibacterial properties against gram-positive bacteria, Staphylococcus aureus, and gram-negative bacteria, Escherichia coli. The lymphocyte viabilities increased after addition of nanopomegranate seeds into the polymer blend. The swelling behavior of blend and hydrogels was dependent on the cross-linking density created by the reaction between poly(vinyl alcohol)/poly(acrylic acid) blend and nanopomegranate seed. Scanning electron microscopy images were highly consistent with Fourier transform infrared spectra, differential scanning calorimetry, and antibacterial activity results.

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