scholarly journals Certain Rheological Aspects of Functionalized Guar Gum

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Meenu Kapoor ◽  
Dhriti Khandal ◽  
Ruchi Gupta ◽  
Pinklesh Arora ◽  
Geetha Seshadri ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Shear Rate ◽  
Guar Gum ◽  
Loss Modulus ◽  
Industrial Applications ◽  
Green Technology ◽  
Low Molecular Weight ◽  
Radiation Processing ◽  
Industrial Sectors ◽  
Wide Acceptance

Guar gum and its derivatives are highly important industrial hydrocolloids as they find applications in various industrial sectors. Guar is a polymer of high molecular weight and its aqueous solutions exhibit unique rheological properties, which has led to its wide acceptance by the industry. In certain industrial applications low molecular weight guar and its derivatives are needed, and conventionally chemical depolymerisation of guar is carried out for this purpose. Radiation processing is a novel and green technology for carrying out depolymerization and can be an ideal substitute for chemical depolymerisation technique. In order to study the effect of radiation on guar derivatives, three types of derivatives have been taken in the present study: carboxymethyl, hydroxyethyl, and methyl guar. The effect of 1–50 KGy radiation dose on the rheological behavior of these derivatives has been studied, and the results have been described in the present paper. The effect on storage and loss modulus with respect to frequency and effect on viscosity with respect to shear rate have been discussed in detail.

The effect of spermidine on the structure, kinetics and stability of proteinase K: spectroscopic and computational approaches

RSC Advances ◽  
2016 ◽  
Vol 6 (107) ◽  
pp. 105476-105486 ◽  
Author(s):  
Mansoore Hosseini-Koupaei ◽  
Behzad Shareghi ◽  
Ali Akbar Saboury ◽  
Fatemeh Davar ◽  
Fatame Raisi
Keyword(s):  
Molecular Weight ◽  
Industrial Applications ◽  
Proteinase K ◽  
Low Molecular Weight ◽  
Computational Approaches ◽  
Low Molecular Weight Compounds

Polyamines (such as spermidine) are low molecular weight compounds which can be used as cosolvents in biological and industrial applications.

A new green technology for direct production of low molecular weight chitosan

2008 ◽  
Vol 74 (1) ◽  
pp. 127-132 ◽  
Author(s):  
Weiping Wang ◽  
Yumin Du ◽  
Yanlin Qiu ◽  
Xiaoying Wang ◽  
Ying Hu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Green Technology ◽  
Low Molecular Weight ◽  
Direct Production ◽  
Low Molecular Weight Chitosan

Influence of Chemical Nature on Flow Behavior of Polymers. I. Shear Rate and Temperature Dependence

1970 ◽  
Vol 43 (5) ◽  
pp. 1109-1115 ◽  
Author(s):  
E. A. Collins ◽  
T. Mass ◽  
W. H. Bauer
Keyword(s):  
Molecular Weight ◽  
Shear Rate ◽  
Chemical Nature ◽  
Flow Behavior ◽  
Capillary Viscometer ◽  
Low Molecular Weight ◽  
Flow Activation Energy ◽  
Flow Activation ◽  
Made In ◽  
Low Shear

Abstract The flow behavior of low molecular weight liquid polybutadiene polymers was studied as a function of shear rate, temperature, and molecular structure. Measurements were made in the temperature range 15 to 50° C and shear rate range 1 to 15,000 sec−1 with a cone and plate and a capillary viscometer. Limiting low shear viscosity, flow activation energy, and critical shear rate marking onset of shear rate thinning were found to be strongly dependent upon the presence of functional groups such as hydroxyl, carboxyl, and nitrile. The modifying groups showed a greater effect than the molecular weight upon the properties measured.

Preparation of Low Molecular Weight Guar Gum for Fracturing by Enzymatic Degradation

2014 ◽  
Vol 971-973 ◽  
pp. 127-130
Author(s):  
Feng Chen ◽  
Xu Guang Wang ◽  
Ren Shu Yang
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Enzymatic Degradation ◽  
Guar Gum ◽  
Low Molecular Weight ◽  
High Concentration ◽  
Different Molecular Weight

Guar gum was subjected to degradation in high concentration aqueous solution by enzymatic treating to obtain high concentration low molecular weight guar gum for fracturing. The study indicates that the high concentration guar gum aqueous solution can be degraded effectively by enzymatic treating. The enzymatic treating conditions were investigated and the optical enzymatic treating pH, temperature and enzyme add amount are respectively 6, 50°C and 0.1g/L, and various of low molecular weight guar gum with different molecular weight can be obtained by controlling the enzymatic treating time.

scholarly journals 1,3:2,4-Dibenzylidene-d-sorbitol (DBS) and its derivatives – efficient, versatile and industrially-relevant low-molecular-weight gelators with over 100 years of history and a bright future

Soft Matter ◽  
2015 ◽  
Vol 11 (24) ◽  
pp. 4768-4787 ◽  
Author(s):  
Babatunde O. Okesola ◽  
Vânia M. P. Vieira ◽  
Daniel J. Cornwell ◽  
Nicole K. Whitelaw ◽  
David K. Smith
Keyword(s):  
Molecular Weight ◽  
Self Assembly ◽  
Industrial Applications ◽  
Low Molecular Weight ◽  
Bright Future ◽  
Wide Range ◽  
The Creation ◽  
Low Molecular Weight Gelators ◽  
Low Molecular Weight Gelator

DBS is an efficient, versatile, low-molecular-weight gelator with a wide-range of industrial applications – greater understanding of its self-assembly and the creation of new derivatives are expanding the scope of this fascinating family of gels.

Consequences and Development of an Invention

1965 ◽  
Vol 38 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Karl Ziegler
Keyword(s):  
Molecular Weight ◽  
Normal Pressure ◽  
Industrial Applications ◽  
Low Molecular Weight ◽  
Max Planck ◽  
Creative Imagination ◽  
New Production ◽  
New Development ◽  
Explosive Wave ◽  
The Many

Abstract The awarding of the Nobel Prize for Chemistry, for the year 1963, is related to the precipitous expansion of macromolecular chemistry and its industrial applications, which began precisely ten years ago at my Max-Planck-Institute for Coal Research, in Mülheim/Ruhr. The suddenness with which this began, and the rapidity with which it was propagated are comparable to an explosion. The energy sources in this case were the ingenuity, activity, creative imagination and bold concepts of the many unnamed chemists, designers and entrepreneurs in the world who have fashioned great industries from our humble beginnings. If today I stand with my colleague Natta, who has been particularly effective in promoting this explosive wave, in the limelight of distinction, and do wish to manifest, with this address, my appreciation for the honor bestowed upon me, I must begin by thanking these many anonymous persons. They, too, deserve this distinction. The extent of this “explosion” may be illustrated by two charts, in which the location of newly-established plants is indicated. The places marked by black circles refer to new production facilities which, though concerned with low molecular weight materials, nevertheless also have some connection with the address I am delivering today (Figures 1 and 2). The new development had its inception near the end of 1953, when I, together with Holzkamp, Breil and Martin observed, for several days, an almost dramatic occurrence: that ethylene gas will polymerize very rapidly with certain catalysts that are extremely easy to prepare, at 100, 20 and 5 atmospheres and, finally, even at normal pressure, to a high molecular weight plastic.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

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