The effect of branched structure on the lamellae evolution under uniaxial extension and SCG resistance of polyolefins

2020 ◽  
Vol 87 ◽  
pp. 106555
Author(s):  
Peiyu Yang ◽  
Li Zhao ◽  
Xuefeng Pan ◽  
Fuqiang Zhou ◽  
Zaixing Yang ◽  
...  
Keyword(s):  
Uniaxial Extension ◽  
Branched Structure

Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

2020 ◽  
pp. 34-39
Author(s):  
Aneta Antczak-Chrobot ◽  
Maciej Wojtczak
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Sugar Beet ◽  
Total Acid ◽  
Average Molecular Mass ◽  
Central European ◽  
Composition And Structure ◽  
Monomeric Composition ◽  
Branched Structure ◽  
Different Origin

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of α-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% α-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

scholarly journals Plant-based fructans for increased animal welfare: provision processes and remaining challenges

2021 ◽  
Author(s):  
A. Zimmermann ◽  
C. Visscher ◽  
M. Kaltschmitt
Keyword(s):  
Animal Welfare ◽  
Dietary Fibre ◽  
Animal Feed ◽  
State Of The Art ◽  
Public Awareness ◽  
Well Being ◽  
Glycosidic Bonds ◽  
Health Promoting ◽  
Branched Structure ◽  
Stimulation Of

AbstractFructans are carbohydrates consisting of fructose monomers linked by β-2,1- and/or β-2,6-glycosidic bonds with linear or branched structure. These carbohydrates belong to the group of prebiotic dietary fibre with health-promoting potential for humans and mammals due to their indigestibility and selective stimulation of microorganisms in the gastrointestinal tract. This makes fructans interesting mainly for healthy food as well as animal feed applications. As a consequence of a growing public awareness for animal welfare, dietary fibre and thus fructans move into the focus as a fibre-rich feeding improving not only animals’ health but also their well-being. Against this background, this paper summarises the known effects of fructans focusing on pigs and highlights the state of the art in fructan production processes from plant material as well as selected current research lines. Additionally, an attempt is made to assess the potential of European fructan production for an application as animal feed. Based on this, challenges in the field of fructan production are addressed and alternative substrates for fructans are discussed and pointed out.

Superstrong Adhesive of Isocyanate-Free Polyurea with a Branched Structure

2021 ◽  
Author(s):  
Hongxing Yang ◽  
Guanben Du ◽  
Zhi Li ◽  
Xin Ran ◽  
Xiaojian Zhou ◽  
...  
Keyword(s):  
Branched Structure

scholarly journals Effect of Surfactant Molecular Structure on Emulsion Stability Investigated by Interfacial Dilatational Rheology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1127
Author(s):  
Yuejie Jin ◽  
Dingrong Liu ◽  
Jinhua Hu
Keyword(s):  
Emulsion Stability ◽  
Chain Structure ◽  
Interfacial Film ◽  
Future Design ◽  
Rheological Method ◽  
Viscoelastic Modulus ◽  
Hydrophobic Chain ◽  
Branched Chain ◽  
The Stability ◽  
Branched Structure

Polyglycerol polyricinolate (PGPR) and polyglycerol-2 dioleate were selected as model surfactants to construct water-in-oil (W/O) emulsions, and the effect of interfacial rheological properties of surfactant film on the stability of emulsions were investigated based on the interfacial dilatational rheological method. The hydrophobicity chain of PGPR is polyricinic acid condensed from ricinic acid, and that of polyglycerol-2 dioleate is oleic acid. Their dynamic interfacial tensions in 15 cycles of interfacial compression-expansion were determined. The interfacial dilatational viscoelasticity was analyzed by amplitude scanning in the range of 1–28% amplitude and frequency sweep in the range of 5–45 mHz under 2% amplitude. It was found that PGPR could quickly reach adsorption equilibrium and form interfacial film with higher interfacial dilatational viscoelastic modulus to resist the deformation of interfacial film caused by emulsion coalescence, due to its branched chain structure and longer hydrophobic chain, and the emulsion thus presented good stability. However, polyglycerol-2 dioleate with a straight chain structure had lower interfacial tension, and it failed to resist the interfacial disturbance caused by coalescence because of its lower interfacial dilatational viscoelastic modulus, and thus the emulsion was unstable. This study reveals profound understanding of the influence of branched structure of PGPR hydrophobic chain on the interfacial film properties and the emulsion stability, providing experimental reference and theoretical guidance for future design or improvement of surfactant.

Multi-walled carbon nanotubes–chitosan with a branched structure modified with ferrocenecarboxylic acid for carcinoembryonic antigen detection

2015 ◽  
Vol 7 (23) ◽  
pp. 10032-10039 ◽  
Author(s):  
Taotao Feng ◽  
Xiuwen Qiao ◽  
Haining Wang ◽  
Zhao Sun ◽  
Chenglin Hong
Keyword(s):  
Carbon Nanotubes ◽  
Carcinoembryonic Antigen ◽  
Modified Electrode ◽  
Electrochemical Immunosensor ◽  
Antigen Detection ◽  
Multi Walled Carbon Nanotubes ◽  
Ferrocenecarboxylic Acid ◽  
Branched Structure ◽  
Walled Carbon Nanotubes

A novel electrochemical immunosensor for the detection of CEA was proposed based on Fc-COOH connected to the branched structure of a MWCNT–CS complex modified electrode.

scholarly journals Stress relaxation and reversed flow of low-density polyethylene melts following uniaxial extension

2012 ◽  
Vol 56 (6) ◽  
pp. 1535-1554 ◽  
Author(s):  
Qian Huang ◽  
Henrik K. Rasmussen ◽  
Anne L. Skov ◽  
Ole Hassager
Keyword(s):  
Stress Relaxation ◽  
Uniaxial Extension ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Reversed Flow ◽  
Polyethylene Melts

scholarly journals Structural features of the exocellular polysaccharides of Mycobacterium tuberculosis

1994 ◽  
Vol 297 (2) ◽  
pp. 351-357 ◽  
Author(s):  
A Lemassu ◽  
M Daffé
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Molecular Mimicry ◽  
Degradation Products ◽  
Cell Envelope ◽  
Gel Filtration ◽  
Structural Features ◽  
Two Dimensional ◽  
Phagocytic Cells ◽  
Molecular Masses ◽  
Branched Structure

The cell envelope which surrounds pathogenic mycobacteria is postulated to be a defence barrier against phagocytic cells and its outermost constituents have a tendency to accumulate in the culture medium. The present work demonstrates that the exocellular material of Mycobacterium tuberculosis contains large amounts of polysaccharides with only traces, if any at all, of lipids. Three types of polysaccharides were purified by anion-exchange and gel-filtration chromatography; all were found to be neutral compounds devoid of acyl substituents. They consisted of D-glucan, D-arabino-D-mannan and D-mannan, which were eluted from gel-filtration columns in positions corresponding to molecular masses of 123, 13 and 4 kDa respectively. Their predominant structural features were determined by the characterization of the per-O-methyl derivatives of enzymic, acetolysis and Smith-degradation products and by 1H- and 13C-n.m.r. spectroscopy of the purified polysaccharides, using mono- and two-dimensional homonuclear chemical-shift correlated spectroscopy and two-dimensional heteronuclear (1H/13C) spectroscopy. The glucan which represented up to 90% of the polysaccharides was composed of repeating units of five or six-->4-alpha-D-Glcp-1--> residues and a -->4-alpha-D-Glcp substituted at position 6 with an alpha-D-Glcp, indicating a glycogen-like highly branched structure not related to the so-called polysaccharide-II previously identified in tuberculin. The arabinomannan consisted of a mannan segment composed of a -->6-alpha-D-Man-1--> core substituted at some positions 2 with an alpha-D-Manp. The arabinan termini of the arabinomannan were found to be extensively capped with mannosyl residues. The possibility that these polysaccharides contribute to the persistence of the tubercle bacillus in the macrophage by molecular mimicry is discussed.

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