Relation between Intrinsic Viscosity and Degree of Polymerization

Nature ◽  
1952 ◽  
Vol 170 (4329) ◽  
pp. 667-667 ◽  
Author(s):  
W. G. HARLAND
Keyword(s):  
Intrinsic Viscosity ◽  
Degree Of Polymerization

Evaluation of post-consumer cellulosic textile waste for chemical recycling based on cellulose degree of polymerization and molar mass distribution

2019 ◽  
Vol 89 (23-24) ◽  
pp. 5067-5075 ◽  
Author(s):  
Helena Wedin ◽  
Marta Lopes ◽  
Herbert Sixta ◽  
Michael Hummel
Keyword(s):  
End Of Life ◽  
Intrinsic Viscosity ◽  
Mass Distribution ◽  
Service Sector ◽  
Molar Mass ◽  
Degree Of Polymerization ◽  
Molar Mass Distribution ◽  
Chemical Recycling ◽  
Cellulose Content ◽  
Cellulosic Textiles

The aim of this study is to improve the understanding of which end-of-life cellulosic textiles can be used for chemical recycling according to their composition, wear life and laundering—domestic versus service sector. For that purpose, end-of-life textiles were generated through laboratorial laundering of virgin fabrics under domestic and industrial conditions, and the cellulose content and its intrinsic viscosity and molar mass distribution were measured in all samples after two, 10, 20, and 50 laundering cycles. Results presented herein also address the knowledge gap concerning polymer properties of end-of-life man-made cellulosic fabrics—viscose and Lyocell. The results show that post-consumer textiles from the home consumer sector, using domestic laundering, can be assumed to have a similar, or only slightly lower, degree of polymerization than the virgin textiles (−15%). Post-consumer textiles from the service sector, using industrial laundering, can be assumed to have a substantially lower degree of polymerization. An approximate decrease of up to 80% of the original degree of polymerization can be expected when they are worn out. A higher relative decrease for cotton than man-made cellulosic textiles is expected. Furthermore, in these laboratorial laundering trials, no evidence evolved that the cellulose content in blended polyester fabrics would be significantly affected by domestic or industrial laundering. With respect to molar mass distribution, domestic post-consumer cotton waste seems to be the most suitable feedstock for chemical textile recycling using Lyocell-type processes, although a pre-treatment step might be required to remove contaminants and lower the intrinsic viscosity to 400–500 ml/g.

scholarly journals Studies in polymerization - II. A method for investigating the relation between the molecular weights and intrinsic viscosities of polymers, and its application to polystyrene

1948 ◽  
Vol 192 (1030) ◽  
pp. 329-339 ◽  
Keyword(s):  
Molecular Weight ◽  
Carbon Tetrachloride ◽  
Intrinsic Viscosity ◽  
Weight Distribution ◽  
Transfer Reaction ◽  
Degree Of Polymerization ◽  
Simple Method ◽  
Absolute Value ◽  
Molecular Weights ◽  
Vinyl Polymers

A simple method for investigating the relation between intrinsic viscosity and molecular weights of vinyl polymers is described. Unbranched polystyrene is found to obey Houwink’s law with an exponent of 0·65. Equations are given for calculating the number average degree of polymerization and molecular weight distribution in unfractionated polymers. It is pointed out that a method is now available for the preparation of polymers with known molecular weights and distribution. The absolute value of the velocity constant for the transfer reaction between styrene and carbon tetrachloride at 60° C is calculated.

Effects of hydrothermal processing on the cellulosic fraction of Eucalyptus globulus wood

Holzforschung ◽  
2013 ◽  
Vol 67 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Carlos Vila ◽  
José Luis Francisco ◽  
Valentin Santos ◽  
Juan Carlos Parajó
Keyword(s):  
Intrinsic Viscosity ◽  
Kinetic Models ◽  
Eucalyptus Globulus ◽  
Treated Wood ◽  
Degree Of Polymerization ◽  
Klason Lignin ◽  
Hydrothermal Processing

Abstract The effects of hydrothermal treatments of Eucalyptus globulus wood have been evaluated in terms of the solid yield and the composition of the treated wood. The contents of cellulose, xylan, and Klason lignin in treated solids were determined and interpreted by means of kinetic models. Particular attention was paid to the degree of polymerization (DP) lowering of cellulose caused by hydrothermal treatments, which was assessed by measurements of intrinsic viscosity.

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.

PURIFICATION AND COMPOSITION OF A POLYURONIDE HEMICELLULOSE ISOLATED FROM WHEAT STRAW

1952 ◽  
Vol 30 (7) ◽  
pp. 515-521 ◽  
Author(s):  
G. A. Adams ◽  
A. E. Castagne
Keyword(s):  
Petroleum Ether ◽  
Wheat Straw ◽  
Intrinsic Viscosity ◽  
Uronic Acid ◽  
Chloroform Solution ◽  
Degree Of Polymerization ◽  
Hot Water ◽  
Molar Ratio ◽  
Fractional Precipitation ◽  
Homogeneous Fraction

A homogeneous polyuronide hemicellulose has been prepared from a crude hemicellulose isolated from wheat straw holocellulose by hot water. The method of preparation consisted of fractional precipitation of the acetylated hemicellulose from chloroform solution by petroleum ether. Approximately 50% of the recovered fractions consisted of a polysaccharide made up of 28 moles of D-xylose, 5 moles of L-arabinose, and 3 moles of uronic acid and having an [Formula: see text] and a molar ratio, methoxyl: uronic anhydride, of approximately 1.0. Intrinsic viscosity measurements indicated a degree of polymerization of approximately 30. Separation of hexosans present in the original hemicellulose showed that they were not chemically combined with the main pentosan fraction. They were recovered admixed with short chain pentosan material containing a higher proportion of arabinose to xylose than the main homogeneous fraction.

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