Viscosity-Molecular Weight of Rubber. Cryoscopic Deviation of Rubber Solutions from Raoult's Law

1942 ◽  
Vol 15 (1) ◽  
pp. 60-71
Author(s):  
A. R. Kemp ◽  
H. Peters
Keyword(s):  
Molecular Weight ◽  
Large Deviations ◽  
Raoult’S Law ◽  
Chain Lengths ◽  
Selection Of ◽  
Raoult's Law

Abstract 1. The cryoscopic method is not satisfactory for polyprenes with chain lengths much greater than about 20 isoprene units on account of the failure of their solutions to obey Raoult's law. 2. Since Staudinger's viscosity-molecular weight constants were in many cases determined on nonideal solutions, this subject will be further investigated. 3. The present work has led to the selection of a Kcm value of 0.75 × 104, which is 25 per cent lower that the value chosen by Staudinger, who used higher polymers which do not behave ideally in solution. 4. The use of Staudinger's equation, M=ηsp/CKm, leads to large deviations with the variations in viscosity usually employed, and this deviation is largely avoided by employing the equation M=(log ηr/C)Kcm.

Cryoscopic and Viscosity Studies of Polyisobutylene. Cryoscopic Deviation of Polyisobutylene Solutions from Raoult's Law

1943 ◽  
Vol 16 (1) ◽  
pp. 69-84
Author(s):  
A. R. Kemp ◽  
H. Peters
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Infinite Dilution ◽  
Freezing Point ◽  
Raoult’S Law ◽  
Ideal Solutions ◽  
Chain Lengths ◽  
Selection Of ◽  
Raoult's Law

Abstract 1. The cryoscopic method is not satisfactory for polyisobutylenes having chain lengths much over 40 isobutylene units, on account of the failure of their solutions to obey Raoult's law. 2. The present work has led to the selection of a Kcm value of 0.75×104 for n-hexane solutions of polyisobutylene for use in the equation M=(log ηr×Kcm)/C. 3. Extrapolation of cryoscopic data obtained on nonideal solutions to infinite dilution gives inordinately high molecular weight values compared with those based on freezing point measurements of ideal solutions. 4. Of several solvents studied, n-hexane was found to be the best for viscosity—molecular weight measurements of polyisobutylene. 5. Fractionation of polyisobutylene by diffusion into mixtures of n-hexane and acetone resulted in the separation of the lower polymer fractions.

Viscosity and Cryoscopic Data on Polystyrene. Discussion of Staudinger's Viscosity Rule

1943 ◽  
Vol 16 (1) ◽  
pp. 58-68
Author(s):  
A. R. Kemp ◽  
H. Peters
Keyword(s):  
Molecular Weight ◽  
Raoult’S Law ◽  
Wide Range ◽  
Raoult's Law

Abstract 1. The cryoscopic method is not satisfactory for polystyrenes containing more than twelve styrene units in the chain on account of the failure of their solutions to obey Raoult's law. 2. The present work has established a new Kcm value of 0.45×104 for benzene solutions of polystyrene to be used in the equation: A Kcm value of 0.6×104 has been similarly established for benzene solutions of polyindene. 3. Increased confidence in the viscosity-molecular weight procedure is derived from the data presented for the new Kcm equivalent covering a wide range of different polymers.

RAOULT'S LAW–BASED METHOD FOR DETERMINATION OF COAL TAR AVERAGE MOLECULAR WEIGHT

2005 ◽  
Vol 24 (8) ◽  
pp. 1886 ◽  
Author(s):  
Derick G. Brown ◽  
Lovleen Gupta ◽  
Horace Keith Moo-Young ◽  
Andrew J. Coleman
Keyword(s):  
Molecular Weight ◽  
Coal Tar ◽  
Average Molecular Weight ◽  
Raoult’S Law ◽  
Raoult's Law

scholarly journals Facile construction of a family of supramolecular gels with good levofloxacin hydrochloride loading capacity

RSC Advances ◽  
2021 ◽  
Vol 11 (21) ◽  
pp. 12641-12648
Author(s):  
Renyuan Chen ◽  
Caidie Xu ◽  
Yihao Lei ◽  
Hongxin Liu ◽  
Yabin Zhu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Alkyl Chain ◽  
Low Molecular Weight ◽  
Loading Capacity ◽  
Supramolecular Gels ◽  
Low Molecular Weight Gelators ◽  
Chain Lengths

A family of low molecular weight gelators with different alkyl chain lengths was constructed, having excellent gelation ability and antibiotic loading capacity. A low molecular weight hydrogelator was obtained by adjusting the length of alkyl chain.

The entropy of liquid mixtures: I. The theory of Raoult's Law

1941 ◽  
Vol 60 (2) ◽  
pp. 76-84 ◽  
Author(s):  
A. J. Staverman ◽  
J. H. van Santen
Keyword(s):  
Liquid Mixtures ◽  
Raoult’S Law ◽  
Raoult's Law
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