scholarly journals Osmometry with single Sephadex beads

1970 ◽  
Vol 119 (1) ◽  
pp. 67-73 ◽  
Author(s):  
A. G. Ogston ◽  
J. D. Wells
Keyword(s):  
Molecular Weight ◽  
Polyvinyl Alcohol ◽  
Osmotic Pressure ◽  
High Molecular Weight ◽  
Molecular Form ◽  
Degree Of Polymerization ◽  
Significant Extent ◽  
Fine Needle ◽  
Single Bead ◽  
Time Required

1. The measurement of osmotic pressure by means of a single bead of Sephadex (Edmond, Farquhar, Dunstone & Ogston, 1968) has been made more precise by immobilizing the bead on a fine needle. The design, calibration and use of the osmometer are described. 2. The method is particularly suitable for measuring high osmotic pressures in solutions of high-molecular-weight solutes, which must not penetrate the Sephadex to a significant extent. 3. With Sephadex G-50 the limit of precision is about 1.5cmH2O and the lower limit of molecular weight for a solute of compact molecular form is about 105. 4. The time required for each equilibration is less than 10min. 5. An impaled bead can be stored in the dry state without affecting its calibration. 6. Measurements on a sample of polyvinyl alcohol, degree of polymerization stated as 1750±50, gave ¯mn 43000±3000 and A2 (6.0±0.24)×10−4.

scholarly journals Preparation of high molecular weight polyvinyl alcohol by emulsifier-free emulsion polymerization

2020 ◽  
Vol 206 ◽  
pp. 02023
Author(s):  
Xinqiu Hong ◽  
Liming Zou ◽  
Jingyang Zhang ◽  
Liujian Wang
Keyword(s):  
Molecular Weight ◽  
Polyvinyl Alcohol ◽  
Emulsion Polymerization ◽  
High Molecular Weight ◽  
Thermo Gravimetric Analysis ◽  
Degree Of Polymerization ◽  
Gravimetric Analysis ◽  
Structure And Property ◽  
H Nmr ◽  
Redox Initiator

In this report, high molecular weight polyvinyl alcohol (PVA) was prepared by emulsifier-free emulsion polymerization, using the redox initiator of potassium persulfate (KPS) / N,N-dimethyl ethanolamine (DMEA). The structure and property of PVA were studied by using ubbelohde viscometer, fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H-NMR), X-ray Diffraction (XRD), differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA). The results showed that the viscosity-average degree of polymerization (DP) of PVA 7506, which was much higher than that of PVA commonly used in industrial production. The syndiotacticity and crystallinity of PVA was 54.2 % and 35.6 %, respectively.

scholarly journals Plasmin Inhibitors in Human Urine

1977 ◽  
Author(s):  
H. Sumi ◽  
Y. Takada ◽  
A. Takada
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Molecular Form ◽  
Membrane Filter ◽  
Gel Filtration ◽  
Total Activity ◽  
Native Form ◽  
Molecular Weights ◽  
Two Peaks

By the gel filtration of urinary protein on Sephadex G-200, two peaks of activity to hydrolyze Nα-acetylglycyl-L-lysine methyl ester (AGLMe) were detected. One was the native form of urokinase, and the molecular weight was about 54,000. The other was of high molecular weight, and eluted in void fraction. The high molecular form was thought to be a complex of urokinase and urinary plasmin inhibitor (UPI). By using Arg-Sepharose, membrane filter (M.W. 10,000), and pevikon block electrophoresis, we could isolate four types of UPI from normal human urine. One UPI was positively charged at pH 8.6, and of high molecular weight. Other types were negatively charged, and the molecular weights by gel filtration on Sephadex G-200 were about 67,000 (UPI6.7), 45,000 (UPI4.5), and 22, 000 (UPI2.2), respectively. In acrylamide disc gel electrophoresis, UPI57 migrated to serum prealbumin fraction, and UPI45 and UPI? 2 were less anionic. Negative-charged UPIs could be adsorbed on trypsin-Sepharose, and were thought to be identical to urinary trypsin inhibitors. Purified UPIs showed strong inhibition on caseinolytic- and esterolytic-activities of plasmin, and the total activity was about 16 UPIU(inhibited 16 casein U of plasmin)/liter of urine.

The Chemical Constitution of Chlorinated Rubber

1951 ◽  
Vol 24 (3) ◽  
pp. 662-663
Author(s):  
René Allirot
Keyword(s):  
Molecular Weight ◽  
Osmotic Pressure ◽  
Hydrogen Chloride ◽  
Intrinsic Viscosity ◽  
Hydrogen Content ◽  
Degree Of Polymerization ◽  
Prolonged Action ◽  
Chlorinated Compounds ◽  
Chemical Constitution ◽  
The Mean

Abstract The results of the work described in the present paper indicate that, by the prolonged action of chlorine on polyisoprenes, chlorinated compounds corresponding to the composition (C10HxCl7)n are formed, irrespective of the molecular weight. The exact hydrogen content of these products can be calculated from determinations of the hydrogen chloride evolved in the reaction, and measurements to this end are in progress. Furthermore, determinations of the osmotic pressure and intrinsic viscosity, which have already been undertaken, should make it possible to determine with certainty the mean degree of polymerization of each fraction.

Production of high-strength fibers of high-molecular-weight polyvinyl alcohol by gel technology

2011 ◽  
Vol 43 (1) ◽  
pp. 41-46 ◽  
Author(s):  
Yu. I. Mitchenko ◽  
A. N. D’yachkov ◽  
L. D. Rudneva
Keyword(s):  
Molecular Weight ◽  
Polyvinyl Alcohol ◽  
High Molecular Weight ◽  
High Strength
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