Application of the Enzymolysis and Membrane Technology in Glucan Extraction and Purification from Grifola frondosa

2012 ◽  
Vol 581-582 ◽  
pp. 11-14
Author(s):  
Chuan Bing Zhou ◽  
Ze Ping Xu ◽  
Wen Juan Feng ◽  
Xin Qing Zhang
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Average Molecular Weight ◽  
Ash Content ◽  
Membrane Technology ◽  
Grifola Frondosa ◽  
Weight Average Molecular Weight ◽  
Extraction And Purification ◽  
Molecular Weight Cutoff ◽  
Better Than

It has been investigated that the application of the enzymolysis and membrane technology in the extraction and purification of glucan from Grifola frondosa. The fruitbody of Grifola frondosa was been used to extract polysaccharides. Compared the yield, protein content and polysaccharide content in the extracts under 3 different process modes, it was found that the procedure processed by complex enzyme was better than the others. Microfiltrated with membrane of 0.2μm aperture and then ultrafiltrated with membrane with molecular weight cutoff of 1000 Dalton, it had glucan retained rate of 80.42% and protein removed rate of 88.27%. GCP experiment indicated that the glucan get from the procedure was a homogeneous polysaccharide with weight average molecular weight of 130355 Dalton. The index of molecular weight distribution was 1.1844. The desalination rate was increased by adding water to the concentrate while ultrafiltration was in progress. When the quantity of water added was 1.5 times of the concentrate volume, it had effective desalination effect with the ash content of 3.79% in final product.

Randomly Branched Polymers. II. Computer Analysis of Gel-Permeation Chromatograms

1976 ◽  
Vol 49 (5) ◽  
pp. 1290-1304
Author(s):  
M. Kurata ◽  
H. Okamoto ◽  
M. Iwama ◽  
M. Abe ◽  
T. Homma
Keyword(s):  
Molecular Weight ◽  
Weight Distribution ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Computer Method ◽  
Branched Polymers ◽  
Branch Points ◽  
Weight Average Molecular Weight ◽  
Degree Of Branching ◽  
Gel Permeation

Abstract An iterative computer method was proposed for estimating the degree of branching and molecular weight distribution simultaneously from a pair of measurements on intrinsic viscosity and gel-permeation chromatography. The validity of the method as applied to randomly branched polymers was tested by using both fractionated and unfractionated samples of branched polystyrenes. It was experimentally concluded that the average number of branch points per unit molecular weight, λ, can be determined by this method with an accuracy of about 15%, and the weight-average molecular weight with accuracy of about 10%.

THE FRACTIONATION OF POLYTHENE

1961 ◽  
Vol 39 (10) ◽  
pp. 1888-1891 ◽  
Author(s):  
W. R. Blackmore ◽  
W. Alexander
Keyword(s):  
Molecular Weight ◽  
Distribution Function ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Negative Binomial ◽  
Average Molecular Weight ◽  
Weight Average Molecular Weight ◽  
Log Normal ◽  
Molecular Weight Fractions ◽  
Good Agreement

An apparatus is described for fractionating large quantities (400 g) of polythene into five roughly equal fractions using a fractional precipitation technique. Application of this method of fractionation to a linear polythene has shown that the width of the molecular-weight distribution of the successive fractions decreases as the fractionation proceeds. Consequently, the initial high-molecular-weight fractions require refractionation to produce equally narrow distributions in them as are found in later fractions. Good agreement is obtained with the experimentally determined values of the number-average and weight-average molecular weight for the parent polymer when the measured values of Mn and Mw for each fraction are used to calculate the values for the parent. The differential molecular-weight distribution function of the parent polymer was calculated on a Bendix G-15 computer from the data for the fractions by using the weight, number-average and weight-average molecular weight, measured for each fraction in conjunction with an assumed log-normal or negative binomial molecular-weight distribution function in each fraction.

The Importance of Rheology in the Processing of Rubber. 1. Rheological Investigations of Rubber Solutions

1959 ◽  
Vol 32 (4) ◽  
pp. 1039-1049 ◽  
Author(s):  
K. Edelmann ◽  
G. Kolbe
Keyword(s):  
Molecular Weight ◽  
Velocity Gradient ◽  
Weight Distribution ◽  
Flow Curve ◽  
Inflection Point ◽  
Average Molecular Weight ◽  
Weight Average Molecular Weight ◽  
Industrial Processing ◽  
A Value ◽  
Macromolecular Substance

Abstract Using the mastication of rubber as an example, it is shown how rheology can be utilized, even in the industrial processing of macromolecular substances, to obtain, from an easily and quickly determined flow curve, a value dependent on the weight average molecular weight, and a numerical value for the polymolecularity. Solutions of chain macromolecules with a sort of Gaussian molecular weight distribution give a symmetrical flow curve with an inflection point which, as the velocity gradient which is independent of the concentration, is a function of the average molecular weight. At the same time the slope of the linearized flow curve provides a numerical value for the polymolecularity of the material in question. In this way, even those changes in a macromolecular substance which occur during factory processing can be measured, as is the case here with masticated rubber.

Metathesis Polymerization of Phenylacetylene by Tungsten Aryloxo Complexes

1995 ◽  
Vol 60 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Hynek Balcar ◽  
Jan Sedláček ◽  
Marta Pacovská ◽  
Vratislav Blechta
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Induction Period ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Molar Ratio ◽  
Weight Average Molecular Weight ◽  
Polymer Yield ◽  
Positive Effect ◽  
Ligand Addition

Catalytic activity of the tungsten aryloxo complexes WCl5(OAr) and WOCl3(OAr), where Ar = 4-t-C4H9C6H4, 2,6-(t-C4H9)2C6H3, 2,6-Cl2C6H3, 2,4,6-Cl3C6H2, and 2,4,6-Br3C6H2 in polymerization of phenylacetylene (20 °C, monomer to catalyst molar ratio = 1 000) was studied. The activity of WCl5(OAr) as unicomponent catalysts increases with increasing electron withdrawing character of the -OAr ligand. Addition of two equivalents of organotin cocatalysts (Me4Sn, Bu4Sn, Ph4Sn, Bu3SnH) to WCl5(O-C6H2Cl3-2,4 ,6) has only slight positive effect (slightly higher polymer yield and/or molecular weight of poly(phenylacetylene)s was achieved). However, in the case of WOCl3(O-C6H3Cl2-2, 6) catalyst, it enhances the activity considerably by eliminating the induction period. Poly(phenylacetylene)s prepared with the catalysts studied have weight-average molecular weight ranging from 100 000 to 200 000. They are trans-prevailing and have relatively low molar fraction of monomer units comprised in cyclohexadiene sequences (about 6%).

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