Statistic thermodynamic analysis of fructans – Part 2: Chain configuration parameters of non-branched and branched fructans – Branching structure and molar mass distribution of branched fructans

2013 ◽  
pp. 219-224 ◽  
Author(s):  
Roland H.F. Beck ◽  
Anton Huber
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
Theoretical Data ◽  
Molar Mass Distribution ◽  
Scattering Data ◽  
Statistical Thermodynamic ◽  
Radius Of Gyration ◽  
X Ray Scattering ◽  
Random Flight Model ◽  
Random Flight

Applying statistical thermodynamic models for chain configurations in combination with linkage analysis, molar mass distribution and small angle X-ray scattering data allow the unambiguous structural elucidation of branched fructans. The radius of gyration of fructans can be accurately predicted by applying a random flight model with bond angle restrictions. The structural factor g has been calculated and correlated with experimental data only allowing a comb shaped structure for branched fructans. A formula for calculating the molar mass distribution of comb shaped branched fructans is proposed. Amalgamation of experimental and theoretical data prove a regular comb shape structure for the branched fructans of U. maritima, L. bulbiferum and A. tequilana.

QELSS diffusion data for moderately broad molar mass distribution polymer samples compared with data from classical gradient techniques

1989 ◽  
Vol 54 (7) ◽  
pp. 1821-1829
Author(s):  
Bedřich Porsch ◽  
Simon King ◽  
Lars-Olof Sundelöf
Keyword(s):  
Diffusion Coefficient ◽  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Diffusion Data ◽  
Mass Distributions ◽  
Classical Diffusion ◽  
Polydisperse Polymer

The differences between the QELSS and classical diffusion coefficient of a polydisperse polymer resulting from distinct definitions of experimentally accessible average values are calculated for two assumed specific forms of molar mass distributions. Predicted deviations are compared with the experiment using NBS 706 standard polystyrene. QELSS Dz of this sample relates within 2-4% to the classical diffusion coefficient, if the Schulz-Zimm molar mass distribution is assumed to be valid. In general, differences between the height-area and QELSS diffusion coefficient of about 20% may be found for Mw/Mn ~ 2, and this value may increase above 35%, if strongly tailing molar mass distribution pertains to the sample.

Evaluation of post-consumer cellulosic textile waste for chemical recycling based on cellulose degree of polymerization and molar mass distribution

2019 ◽  
Vol 89 (23-24) ◽  
pp. 5067-5075 ◽  
Author(s):  
Helena Wedin ◽  
Marta Lopes ◽  
Herbert Sixta ◽  
Michael Hummel
Keyword(s):  
End Of Life ◽  
Intrinsic Viscosity ◽  
Mass Distribution ◽  
Service Sector ◽  
Molar Mass ◽  
Degree Of Polymerization ◽  
Molar Mass Distribution ◽  
Chemical Recycling ◽  
Cellulose Content ◽  
Cellulosic Textiles

The aim of this study is to improve the understanding of which end-of-life cellulosic textiles can be used for chemical recycling according to their composition, wear life and laundering—domestic versus service sector. For that purpose, end-of-life textiles were generated through laboratorial laundering of virgin fabrics under domestic and industrial conditions, and the cellulose content and its intrinsic viscosity and molar mass distribution were measured in all samples after two, 10, 20, and 50 laundering cycles. Results presented herein also address the knowledge gap concerning polymer properties of end-of-life man-made cellulosic fabrics—viscose and Lyocell. The results show that post-consumer textiles from the home consumer sector, using domestic laundering, can be assumed to have a similar, or only slightly lower, degree of polymerization than the virgin textiles (−15%). Post-consumer textiles from the service sector, using industrial laundering, can be assumed to have a substantially lower degree of polymerization. An approximate decrease of up to 80% of the original degree of polymerization can be expected when they are worn out. A higher relative decrease for cotton than man-made cellulosic textiles is expected. Furthermore, in these laboratorial laundering trials, no evidence evolved that the cellulose content in blended polyester fabrics would be significantly affected by domestic or industrial laundering. With respect to molar mass distribution, domestic post-consumer cotton waste seems to be the most suitable feedstock for chemical textile recycling using Lyocell-type processes, although a pre-treatment step might be required to remove contaminants and lower the intrinsic viscosity to 400–500 ml/g.

Synthesis and liquid crystalline properties of azobenzene-containing poly(vinyl ether)s with narrow molar mass distribution

1995 ◽  
Vol 196 (10) ◽  
pp. 3187-3196 ◽  
Author(s):  
Emo Chiellini ◽  
Giancarlo Galli ◽  
Maria Chiara Bignozzi ◽  
Sante A. Angeloni ◽  
Marco Fagnani ◽  
...  
Keyword(s):  
Vinyl Ether ◽  
Mass Distribution ◽  
Liquid Crystalline ◽  
Molar Mass ◽  
Molar Mass Distribution

scholarly journals Polyethylene loss of ductility during oxidation: Effect of initial molar mass distribution

2018 ◽  
Vol 149 ◽  
pp. 78-84 ◽  
Author(s):  
Armando F. Reano ◽  
Alain Guinault ◽  
Emmanuel Richaud ◽  
Bruno Fayolle
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
Molar Mass Distribution ◽  
Oxidation Effect

scholarly journals Low-resolution structure of the soluble domain GPAA1 (yGPAA170–247) of the glycosylphosphatidylinositol transamidase subunit GPAA1 from Saccharomyces cerevisiae

2013 ◽  
Vol 33 (2) ◽  
Author(s):  
Wuan Geok Saw ◽  
Birgit Eisenhaber ◽  
Frank Eisenhaber ◽  
Gerhard Grüber
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Solution Structure ◽  
Scattering Data ◽  
Radius Of Gyration ◽  
Low Resolution ◽  
X Ray Scattering ◽  
Eukaryotic Proteins ◽  
Structural Content ◽  
Α Helix ◽  
Gpi Transamidase

The GPI (glycosylphosphatidylinositol) transamidase complex catalyses the attachment of GPI anchors to eukaryotic proteins in the lumen of ER (endoplasmic reticulum). The Saccharomyces cerevisiae GPI transamidase complex consists of the subunits yPIG-K (Gpi8p), yPIG-S (Gpi17p), yPIG-T (Gpi16p), yPIG-U (CDC91/GAB1) and yGPAA1. We present the production of the two recombinant proteins yGPAA170–247 and yGPAA170–339 of the luminal domain of S. cerevisiae GPAA1, covering the amino acids 70–247 and 70–339 respectively. The secondary structural content of the stable and monodisperse yGPAA170–247 has been determined to be 28% α-helix and 27% β-sheet. SAXS (small-angle X-ray scattering) data showed that yGPAA170–247 has an Rg (radius of gyration) of 2.72±0.025 nm and Dmax (maximum dimension) of 9.14 nm. These data enabled the determination of the two domain low-resolution solution structure of yGPAA170–247. The large elliptical shape of yGPAA170–247 is connected via a short stalk to the smaller hook-like domain of 0.8 nm in length and 3.5 nm in width. The topological arrangement of yGPAA170–247 will be discussed together with the recently determined low-resolution structures of yPIG-K24–337 and yPIG-S38–467 from S. cerevisiae in the GPI transamidase complex.

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