Application of gel permeation chromatography and viscometry for characterization of branched polydisperse polycarbonate

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.

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Gel permeation chromatography – Atmospheric pressure chemical ionization – Mass spectrometry for characterization of polymer additives

International Journal of Polymer Analysis and Characterization ◽

10.1080/1023666x.2016.1276740 ◽

2017 ◽

Vol 22 (3) ◽

pp. 210-214 ◽

Cited By ~ 3

Author(s):

Adrian Boborodea ◽

Alan Brookes

Keyword(s):

Atmospheric Pressure ◽

Chemical Ionization ◽

Atmospheric Pressure Chemical Ionization ◽

Gel Permeation Chromatography ◽

Chemical Ionization Mass Spectrometry ◽

Ionization Mass ◽

Gel Permeation ◽

Pressure Chemical Ionization ◽

Pressure Chemical

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

Radiochimica Acta ◽

10.1524/ract.2000.88.2.095 ◽

2000 ◽

Vol 88 (2) ◽

Cited By ~ 9

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

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

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.747.753 ◽

2013 ◽

Vol 747 ◽

pp. 753-756 ◽

Cited By ~ 1

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.

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