New Absolute Molecular Weight Method for Linear Polymers

1959 ◽  
Vol 32 (1) ◽  
pp. 99-106
Author(s):  
F. Bueche ◽  
S. W. Harding
Keyword(s):  
Molecular Weight ◽  
Linear Polymers ◽  
Weight Method

A new absolute molecular weight method for linear polymers

1958 ◽  
Vol 32 (124) ◽  
pp. 177-186 ◽  
Author(s):  
F. Bueche ◽  
S. W. Harding
Keyword(s):  
Molecular Weight ◽  
Linear Polymers ◽  
Weight Method

Processability predictions for mechanically recycled blends of linear polymers

2020 ◽  
Vol 40 (9) ◽  
pp. 771-781
Author(s):  
Janne van Gisbergen ◽  
Jaap den Doelder
Keyword(s):  
Molecular Weight ◽  
Circular Economy ◽  
Melt Flow Index ◽  
Building Blocks ◽  
Experimental Designs ◽  
New Method ◽  
Flow Index ◽  
Linear Polymers ◽  
Combined Method

AbstractRecycling of thermoplastic polymers is an important element of sustainable circular economy practices. The quality of mechanically recycled polymers is a concern. A method is presented to predict the structure and processability of recycled blends of polymers based on processability knowledge of their virgin precursor components. Blending rules at molecular weight distribution level are well established and form the foundation of the new method. Two essential fundamental building blocks are combined with this foundation. First, component and blend structure are related to viscosity via tube theories. Second, viscosity is related to melt flow index via a continuum mechanics approach. Emulator equations are built based on virtual experimental designs for fast forward and reverse calculations directly relating structure to viscosity and processability. The new combined method is compared with empirical blend rules, and shows important similarities and also clear quantitative differences. Finally, the new method is applied to practical recycling quality challenges.

Synthesis and Properties of Regular Star Polybutadienes with 32 Arms

1992 ◽  
Vol 65 (2) ◽  
pp. 303-314 ◽  
Author(s):  
L-L. Zhou ◽  
N. Hadjichristidis ◽  
P. M. Toporowski ◽  
J. Roovers
Keyword(s):  
Molecular Weight ◽  
Coupling Agent ◽  
Hard Sphere ◽  
Star Polymers ◽  
Radius Of Gyration ◽  
Linear Polymers ◽  
Solution Properties ◽  
Mean Square ◽  
Dilute Solution ◽  
Dilute Solution Properties

Abstract A dendrimer carbosilane containing 32 Si—Cl bonds in the perimeter has been prepared and has been used as a coupling agent to prepare 32-arm star polybutadienes. The dilute-solution properties 〈RG2〉, A2, [η], and D0 have been measured in one good solvent and in one ¸ -solvent. The dimensions of the 32-arm star polymers are compared with those of linear polymers at constant molecular weight. It is shown that the 32-arm star polybutadiene has the characteristic properties of a hard-sphere molecule in dilute solution. The equivalent hard-sphere radii calculated from A2, D0 and [η] are identical and 1.29 times larger than the root mean-square radius of gyration. The Daoud—Cotton scaling model for stars is also tested.

DISSOCIATION AND SUBUNIT SIZE OF β-LIPOVITELLIN

1965 ◽  
Vol 43 (6) ◽  
pp. 661-670 ◽  
Author(s):  
W. H. Cook ◽  
R. A. Wallace
Keyword(s):  
Molecular Weight ◽  
Light Scattering ◽  
Dissociation Constants ◽  
Dry Weight ◽  
Ph Values ◽  
Scattering Measurements ◽  
Solvent Displacement ◽  
Weight Method ◽  
Kinetics Of ◽  
Good Agreement

Dissociation of β-lipovitellin was detectable at pH 5.8 and increased linearly with pH. Light-scattering measurements at different pH values were consistent with a molecular weight of 2.27 × 105 for the subunit and twice this value for the associated form, confirming that it is a monomer–dimer system. This value for the molecular weight of the dimer is somewhat higher than previously reported (4.0 × 105) partly because a solvent displacement correction was used in estimating concentration by a dry weight method. Dissociation constants evaluated from light-scattering measurements and by ultracentrifugal separation were 22 × 10−6 and 29 × 10−6 respectively, in good agreement with provisional values already reported. Preliminary studies on the kinetics of this reaction indicate that, when the pH is altered, dissociation reaches the new equilibrium in about 0.5 minute but that reassociation requires about 50 minutes.

scholarly journals Anti-Inflammatory Properties of Dendrimersper se

2011 ◽  
Vol 11 ◽  
pp. 1367-1382 ◽  
Author(s):  
Myriam Hayder ◽  
Séverine Fruchon ◽  
Jean-Jacques Fournié ◽  
Mary Poupot ◽  
Rémy Poupot
Keyword(s):  
Molecular Weight ◽  
Linear Polymers ◽  
Inflammatory Disorders ◽  
Drug Candidates ◽  
The Past ◽  
Anti Inflammatory

Dendrimers are polybranched and polyfunctionalized tree-like polymers. Unlike linear polymers, they have perfectly defined structure and molecular weight, due to their iterative step-by-step synthesis. Their multivalent structure and supramolecular properties have made them attractive nanotools for applications, particularly in biology and medicine. Among the different biological and medical properties of dendrimers that have been developed over the past decades, the anti-inflammatory properties of several groups of dendrimers are the most recently discovered. Thereof, dendrimers emerge as promising, although heretical, drug candidates for the treatment of still-uncured chronic inflammatory disorders. This mini-review is based on the five main scientific articles giving an overview of what can be the spectrum of anti-inflammatory characteristics displayed by dendrimers.

scholarly journals Determining the Dilution Exponent for Entangled 1,4-Polybutadienes Using Blends of Near-Monodisperse Star with Unentangled, Low Molecular Weight Linear Polymers

2019 ◽  
Vol 52 (4) ◽  
pp. 1757-1771 ◽  
Author(s):  
Ryan Hall ◽  
Beom-Goo Kang ◽  
Sanghoon Lee ◽  
Taihyun Chang ◽  
David C. Venerus ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
Linear Polymers
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