The effect of pyrolysis on the chemical, thermal and rheological properties of pitch

Soft Matter ◽  
2021 ◽  
Vol 17 (39) ◽  
pp. 8925-8936
Author(s):  
Heedong Yoon ◽  
Zachary R. Hinton ◽  
James Heinzman ◽  
Clarence E. Chase ◽  
Manesh Gopinadhan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Analysis ◽  
Rheological Properties ◽  
Clear Correlation ◽  
Aromatic Species

There is a clear correlation between pyrolysis time and the extensional properties of pitch. Chemical analysis shows an increase in aromatic species and a shift to higher molecular weight. We hypothesize that these results are important in understanding pitch spinnability.

scholarly journals Composition of low-molecular-weight glutenin subunits in common wheat (Triticum aestivum L.) and their effects on the rheological properties of dough

2021 ◽  
Vol 16 (1) ◽  
pp. 641-652
Author(s):  
Sławomir Franaszek ◽  
Bolesław Salmanowicz
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Common Wheat ◽  
High Performance ◽  
Triticum Aestivum L ◽  
Quality Parameters ◽  
Low Molecular Weight ◽  
Wheat Varieties ◽  
Breeding Lines ◽  
Capillary Zone

Abstract The main purpose of this research was the identification and characterization of low-molecular-weight glutenin subunit (LMW-GS) composition in common wheat and the determination of the effect of these proteins on the rheological properties of dough. The use of capillary zone electrophoresis and reverse-phase high-performance liquid chromatography has made it possible to identify four alleles in the Glu-A3 and Glu-D3 loci and seven alleles in the Glu-B3 locus, encoding LMW-GSs in 70 varieties and breeding lines of wheat tested. To determine the technological quality of dough, analyses were performed at the microscale using a TA.XT Plus Texture Analyzer. Wheat varieties containing the Glu-3 loci scheme (Glu-A3b, Glu-A3f at the Glu-A3 locus; Glu-B3a, Glu-B3b, Glu-B3d, Glu-B3h at the Glu-B3 locus; Glu-D3a, Glu-D3c at the Glu-D3 locus) determined the most beneficial quality parameters.

Effect of Different Molecular Weight of PEG on the Crystallization Behaviors of Binary Polymer Blends PLA/TPS

2021 ◽  
Vol 1035 ◽  
pp. 918-924
Author(s):  
Teng Zhang ◽  
Su Mei Zheng
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Flow Rate ◽  
Crystallization Rate ◽  
Thermoplastic Starch ◽  
Extrusion Process ◽  
Poly Lactic Acid ◽  
Melt Flow Rate ◽  
Poly Ethylene ◽  
Different Molecular Weight

Serial poly (lactic acid) (PLA) and thermoplastic starch (TPS) blends (with a fixed content of 20 wt.% TPS) were prepared by melt extrusion process. The effect of different molecular weight of PEG on the thermal and rheological properties of PLA/TPS blends was studied by the melt flow rate (MFR) and DSC analysis. The results showed that the molecular weight of PEG influenced the miscibility and crystallization behavior of PLA/TPS blends. Blend added with PEG400 showed a single Tg, and blends with PEG600 provided remarkable improvement of rheological properties with an increase in flow rate to 49.02 g/10 min. 4% content of poly (ethylene glycol) (PEG) can positively contribute to improve crystallization rate of PLA by reducing the melting temperature and cold crystallization temperature.

scholarly journals Analysis of Structural and Functional Differences of Glucans Produced by the Natively Released Dextransucrase of Liquorilactobacillus hordei TMW 1.1822

2020 ◽  
Vol 193 (1) ◽  
pp. 96-110 ◽  
Author(s):  
Jonas Schmid ◽  
Daniel Wefers ◽  
Rudi F. Vogel ◽  
Frank Jakob
Keyword(s):  
Molecular Weight ◽  
Secondary Structure ◽  
Rheological Properties ◽  
Viscoelastic Fluid ◽  
Size Structure ◽  
Molecular Size ◽  
Molecular Structures ◽  
Rheological Measurements ◽  
Functional Differences ◽  
Functionally Diverse

AbstractThe properties of the glucopolymer dextran are versatile and linked to its molecular size, structure, branching, and secondary structure. However, suited strategies to control and exploit the variable structures of dextrans are scarce. The aim of this study was to delineate structural and functional differences of dextrans, which were produced in buffers at different conditions using the native dextransucrase released by Liquorilactobacillus (L.) hordei TMW 1.1822. Rheological measurements revealed that dextran produced at pH 4.0 (MW = 1.1 * 108 Da) exhibited the properties of a viscoelastic fluid up to concentrations of 10% (w/v). By contrast, dextran produced at pH 5.5 (MW = 1.86 * 108 Da) was gel-forming already at 7.5% (w/v). As both dextrans exhibited comparable molecular structures, the molecular weight primarily influenced their rheological properties. The addition of maltose to the production assays caused the formation of the trisaccharide panose instead of dextran. Moreover, pre-cultures of L. hordei TMW 1.1822 grown without sucrose were substantial for recovery of higher dextran yields, since the cells stored the constitutively expressed dextransucrase intracellularly, until sucrose became available. These findings can be exploited for the controlled recovery of functionally diverse dextrans and oligosaccharides by the use of one dextransucrase type.

scholarly journals Synergistic toughening of polypropylene with ultra-high molecular weight polyethylene and elastomer-olefin block copolymers

RSC Advances ◽  
2019 ◽  
Vol 9 (41) ◽  
pp. 23994-24002 ◽  
Author(s):  
Lucheng Qi ◽  
Lei Wu ◽  
Ren He ◽  
Hui Cheng ◽  
Boping Liu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Block Copolymers ◽  
Rheological Properties ◽  
High Molecular Weight ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Twin Screw ◽  
Ultra High Molecular Weight

Blends of polypropylene (PP) and ultra-high molecular weight polyethylene (UHMWPE) with elastomer-olefin block copolymers (OBC) were prepared using an ultrasonic twin-screw extruder, and their mechanical and rheological properties were investigated.

scholarly journals Low Molecular Weight Gelators Based on Functionalized l-Dopa Promote Organogels Formation

Gels ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 27 ◽  
Author(s):  
Demetra Giuri ◽  
Nicola Zanna ◽  
Claudia Tomasini
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Rheological Properties ◽  
Rhodamine B ◽  
Lauric Acid ◽  
Water Solution ◽  
Preliminary Test ◽  
Low Molecular Weight ◽  
Coupling Reactions ◽  
Low Molecular Weight Gelators

We prepared the small pseudopeptide Lau-l-Dopa(OBn)2-d-Oxd-OBn (Lau = lauric acid; l-Dopa = l-3,4-dihydroxyphenylalanine; d-Oxd = (4R,5S)-4-methyl-5-carboxyl-oxazolidin-2-one; Bn = benzyl) through a number of coupling reactions between lauric acid, protected l-Dopa and d-Oxd with an excellent overall yield. The ability of the product to form supramolecular organogels has been tested with different organic solvents of increasing polarity and compared with the results obtained with the small pseudopeptide Fmoc-l-Dopa(OBn)2-d-Oxd-OBn. The mechanical and rheological properties of the organogels demonstrated solvent-dependent properties, with a storage modulus of 82 kPa for the ethanol organogel. Finally, to have a preliminary test of the organogels’ ability to adsorb pollutants, we treated a sample of the ethanol organogel with an aqueous solution of Rhodamine B (RhB) for 24 h. The water solution slowly lost its pink color, which became trapped in the organogel.

Effect of molecular weight and chemical structure on thermal and rheological properties of gelling κ/ι-hybrid carrageenan solutions

2011 ◽  
Vol 85 (2) ◽  
pp. 429-438 ◽  
Author(s):  
Hiléia K.S. Souza ◽  
Loic Hilliou ◽  
Margarida Bastos ◽  
Maria Pilar Gonçalves
Keyword(s):  
Molecular Weight ◽  
Rheological Properties ◽  
Chemical Structure
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