The melt viscosity-molecular weight relationship for linear polymers

1987 ◽  
Vol 20 (9) ◽  
pp. 2226-2237 ◽  
Author(s):  
Ralph H. Colby ◽  
Lewis J. Fetters ◽  
William W. Graessley
Keyword(s):  
Molecular Weight ◽  
Linear Polymers ◽  
Melt Viscosity ◽  
Weight Relationship

Investigating the Rheological Properties and Heat Stability of Polyarylsulphone Sulphides of Domestic Grades

2017 ◽  
Vol 44 (1) ◽  
pp. 23-26
Author(s):  
A.B. Baranov ◽  
I.D. Simonov-Emel'yanov ◽  
T.I. Andreeva ◽  
T.N. Prudskova ◽  
V.I. Sazikov
Keyword(s):  
Molecular Weight ◽  
Heat Stability ◽  
Chain Structure ◽  
Low Flow ◽  
Processing Temperature ◽  
Rheological Characteristics ◽  
Melt Viscosity ◽  
Full Curve ◽  
Temperature Range ◽  
Service Characteristics

The rheological characteristics of melts of polyarylsulphone sulphides of domestic grades were investigated in the temperature range 240–360°C. Full curves of heat stability were obtained, and formulae were proposed for their description. Polyarylsulphone sulphides (PSPSs) are heat-resistant polymers of structural designation of the polysulphone (PSP) class, the domestic production technology of which was developed at OAO “Institut plastmass”, which makes it possible to carry out the production of a wide grade range of PSP of different polymer chain structure and molecular weight. The main problem in the processing of PSPSs is their high melt viscosity and fairly low flow. Increase in the processing temperature lowers their melt viscosity, but there is then the danger of thermooxidative degradation of the polymer and consequently of deterioration in the service characteristics and appearance of articles. The aim of this work was to investigate the rheological characteristics and to obtain the full curve of heat stability for domestic grades of PSPSs and PSP of different molecular weight in a wide processing temperature range.

Viscosity—molecular weight relationship for cellulose tripropionate in chloroform

Polymer ◽  
1979 ◽  
Vol 20 (6) ◽  
pp. 667-669 ◽  
Author(s):  
G.R. Farvardin ◽  
P. Howard
Keyword(s):  
Molecular Weight ◽  
Weight Relationship

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.

Intrinsic viscosity–molecular weight relationship for low molecular weight nylon 6

1968 ◽  
Vol 12 (9) ◽  
pp. 2105-2109 ◽  
Author(s):  
P. Hague ◽  
M. B. Huglin ◽  
B. L. Johnson ◽  
J. Smith
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Nylon 6 ◽  
Low Molecular Weight ◽  
Weight Relationship

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.

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