Structural Characterization of Poly(o-Tolidine)

2005 ◽  
Vol 494 ◽  
pp. 357-362 ◽  
Author(s):  
G. Ćirić-Marjanović ◽  
B. Marjanović ◽  
M. Trchová ◽  
P. Holler
Keyword(s):  
Spectroscopic Analysis ◽  
Platinum Electrode ◽  
Electrochemical Polymerization ◽  
Oxidative Polymerization ◽  
Gel Permeation Chromatography ◽  
Chemical Oxidative Polymerization ◽  
Ammonium Peroxydisulfate ◽  
Gel Permeation ◽  
Ir Spectroscopic

A new polymer of o-tolidine was synthesized by chemical and electrochemical methods from its aqueous solutions in 1M HCl. Chemical oxidative polymerization was performed using ammonium peroxydisulfate as an oxidant. Electrochemical polymerization was carried out using two steps which were successively repeated in a continual process: first, holding the working platinum electrode under a constant anodic potential of +1.6 V, and second, the voltammetric cycle between +0.3 and +1.6 V. During this procedure a polymeric film was formed on the working electrode. Polymerization of o-tolidine was exactly proved by gel permeation chromatography evidencing the chains of molar masses in the range of 1000 – 12600 g mol─1. The structure of poly(o-tolidines) obtained by both chemical and electrochemical procedures was studied by IR spectroscopy. Coupling pathway N–C during polymerization, existence of quinonoid rings and hydrogen bonding involving NH group in polymeric products are revealed by IR spectroscopic analysis. The mechanism of o-tolidine oxidative polymerization is proposed.

scholarly journals Molar mass determination of lignins and characterization of their polymeric structures by multi-detector gel permeation chromatography

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Evamaria C. Gaugler ◽  
Wolfgang Radke ◽  
Andrew P. Vogt ◽  
Dawn A. Smith
Keyword(s):  
Molar Mass ◽  
Lithium Bromide ◽  
Gel Permeation Chromatography ◽  
Mass Determination ◽  
Organosolv Lignin ◽  
Gel Permeation ◽  
Softwood Kraft Lignin ◽  
Polymeric Structures

AbstractMolar masses, Mark-Houwink-Sakurada (MHS) exponents, and refractive index increments (dn/dc) for three lignins were determined without derivatization by multi-detector gel permeation chromatography (GPC) in dimethylformamide (DMF) with 0.05 M lithium bromide (LiBr). The lack of effectiveness of fluorescence filters on molar mass determination by GPC-multi-angle laser light scattering (MALS) was confirmed for softwood kraft lignin (Indulin AT) and revealed for mixed hardwood organosolv lignin (Alcell) as well as soda straw/grass lignin (Protobind 1000). GPC with viscometry detection confirmed that these lignins were present as compact molecules. The MHS exponent α for Indulin AT and Alcell was in the order of 0.1. Additionally, the intrinsic viscosity of Protobind 1000 for a given molar mass was much lower than that of either Alcell or Indulin AT. This is the first report of dn/dc values for these three lignins in DMF with 0.05 M LiBr.

Synthesis and chromatographic characterization of [Tc-99m]technetium-humic acid species

2000 ◽  
Vol 88 (2) ◽  
Author(s):  
D. Rößler ◽  
K. Franke ◽  
R. Süß ◽  
E. Becker ◽  
H. Kupsch
Keyword(s):  
Humic Acid ◽  
Stannous Chloride ◽  
Gel Permeation Chromatography ◽  
Paper Electrophoresis ◽  
Gel Permeation ◽  
Soil Humic Acid ◽  
Chromatographic Characterization ◽  
Ph Dependent ◽  
Layer Chromatography

A natural moor soil humic acid (HA) was labeled with Tc-99m via reduction of pertechnetate with stannous chloride. The humic acid species obtained were characterized by thin layer chromatography (TLC), gel permeation chromatography (GPC), sequential chromatographic analysis (SCA), paper electrophoresis and micropore filtration. Labeling was found to take place in all ranges of molecular weight. Due to the complex humic acid composition and the formation of hydroxo species the labeling yields strongly depend on the separation conditions, ranging from 42% to 80%. The pH-dependent distribution of mobile and immobile species was determined by SCA for HTcO

Kinetic Studies on the Curing Reactions of Fluoroepoxy Oligomer and Cycloaliphatic Amine

2013 ◽  
Vol 747 ◽  
pp. 753-756 ◽  
Author(s):  
Thitinun Chongtum ◽  
Wunpen Chonkaew
Keyword(s):  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Kinetic Studies ◽  
Equivalent Weight ◽  
Number Average Molecular Weight ◽  
Polymeric Systems ◽  
Acid Titration ◽  
Curing Kinetic ◽  
Gel Permeation

The curing kinetic analysis is an important technique for the characterization of the curing behavior of reactive polymeric systems. In this study, fluoroepoxy oligomer was synthesized from trifluoromethyl aniline and epichlorohydrin. The epoxide equivalent weight (EEW) and the number average molecular weight (Mn) of the systhesized fluroepoxy oligomer determined from acid titration and gel permeation chromatography were found to be 312.16 g/eq and 534 g/mol, respectively. The mixtures of the fluoroepoxy oligomer were mixed with the cycloaliphatic amine in various stiochiometric ratios (1:1, 1: 1.5 and 1:2). The effects of the stiochiometric ratio on the curing behaviors were studied using both isothermal and non-isothermal DSC methods. Ozawas, Kissingers and Friedmans methods were employed to investigate the kinetic parameters. The results showed that the peak temperature (Tp) increased with the increasing heating rate. The activation energy (Ea) calculated from Ozawas and Kissingers methods were much larger than that from Friedmans method.

scholarly journals Elemental and spectroscopic characterization of humic acids fractionated by gel permeation chromatography

Agronomie ◽  
2000 ◽  
Vol 20 (5) ◽  
pp. 491-504 ◽  
Author(s):  
Aaziz Ouatmane ◽  
Valeria Dorazio ◽  
Mohamed Hafidi ◽  
Jean-Claude Revel ◽  
Nicola Senesi
Keyword(s):  
Humic Acids ◽  
Gel Permeation Chromatography ◽  
Spectroscopic Characterization ◽  
Gel Permeation

Preparation and characterization of poly(3-methylthiophene)/CeY zeolite composites

RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49343-49349 ◽  
Author(s):  
Pengyue Han ◽  
Junjie Liao ◽  
Jinyu Chang ◽  
Liping Chang ◽  
Weiren Bao
Keyword(s):  
Oxidative Polymerization ◽  
Oxidizing Agent ◽  
Chemical Oxidative Polymerization

Poly(3-methylthiophene)/CeY zeolite nanocomposites are prepared by chemical oxidative polymerization using anhydrous FeCl3 as the oxidizing agent.

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