Application of Elasticity Models with Constraints on Chains and Junctions to Characterization of Randomly Crosslinked Networks

J. P. Queslel

doi:10.5254/1.3536276

Application of Elasticity Models with Constraints on Chains and Junctions to Characterization of Randomly Crosslinked Networks

Rubber Chemistry and Technology ◽

10.5254/1.3536276 ◽

1989 ◽

Vol 62 (5) ◽

pp. 800-819 ◽

Cited By ~ 2

Author(s):

J. P. Queslel

Keyword(s):

Molecular Weight ◽

Deformation Model ◽

Chain Model ◽

Stress Strain ◽

Swelling Equilibrium ◽

Minimum Number ◽

Affine Deformation ◽

Crosslinked Networks ◽

Cycle Rank

Abstract Characterization of randomly crosslinked networks requires a topological description of imperfect network structure and a molecular-elasticity theory, preferably with a minimum number of adjustable parameters, relating macroscopic stress and strain or swelling ratios to molecular deformation. It is shown that simple relationships exist between the molecular weight between consecutive junctions, the molecular weight of linear precursor chains, the cycle rank, and the number of junctions for networks having no defects other than chain ends. The idealized affine deformation model (in which the constraints on junction fluctuations are infinite) and the idealized phantom-chain model (in which the constraints are absent) are inadequate for network characterization. The more realistic Flory-Erman constrained junction model is applied to the description of cis-polyisoprene cured with dicumyl peroxide. Swelling equilibrium experiments are in agreement with stress-strain measurements. Analysis of these stress-strain data with the constrained-junction and constrained-chain models gives similar results. This validates the Flory hypothesis that it is generally sufficient to concentrate the effects of the constraints on the junctions. Nevertheless, the constrained chain model proposed by Erman and Monnerie has the advantage of depending on one parameter, KG, instead of two, κ and ζ, for the constrained junction model.

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Experimental characterization of composites to support an orthotropic plasticity material model

Journal of Composite Materials ◽

10.1177/0021998317733319 ◽

2017 ◽

Vol 52 (14) ◽

pp. 1847-1872 ◽

Cited By ~ 5

Author(s):

Bilal Khaled ◽

Loukham Shyamsunder ◽

Canio Hoffarth ◽

Subramaniam D Rajan ◽

Robert K Goldberg ◽

...

Keyword(s):

Material Model ◽

Unidirectional Composite ◽

Deformation Model ◽

Test Results ◽

Dynamic Impact ◽

Test Procedures ◽

Stress Strain ◽

Damage And Failure ◽

Orthotropic Behavior

Test procedures for characterizing the orthotropic behavior of a unidirectional composite at room temperature and quasi-static loading conditions are developed and discussed. The resulting data consisting of 12 stress–strain curves and associated material parameters are used in a newly developed material model—an orthotropic elasto-plastic constitutive model that is driven by tabulated stress–strain curves and other material properties that allow for the elastic and inelastic deformation model to be combined with damage and failure models. A unidirectional composite—T800/F3900, commonly used in the aerospace industry, is used to illustrate how the experimental procedures are developed and used. The generated data are then used to model a dynamic impact test. Results show that the developed framework implemented into a special version of LS-DYNA yields reasonably accurate predictions of the structural behavior.

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Theoretical Equilibrium Moduli and Swelling Extents for Elastomers Crosslinked in Solution

Rubber Chemistry and Technology ◽

10.5254/1.3538241 ◽

1990 ◽

Vol 63 (1) ◽

pp. 46-55 ◽

Cited By ~ 5

Author(s):

J. P. Queslel ◽

J. E. Mark

Keyword(s):

Volume Fraction ◽

Amorphous Polymer ◽

Polymer Networks ◽

Deformation Model ◽

Chain Model ◽

Swelling Properties ◽

Plateau Modulus ◽

Contour Model ◽

Polymer Volume ◽

Affine Deformation

Abstract Equilibrium elongation moduli and swelling properties have been calculated for amorphous polymer networks prepared in a diluted reference state of polymer volume fraction υ2C. The three molecular elasticity theories employed are based on (i) an idealized affine deformation model (in which the constraints on junction fluctuations are infinite), (ii) an idealized phantom chain model (in which the constraints are absent), and (iii) the more realistic Flory-Erman theory (in which the constraints vary with crosslinking conditions, degree of swelling, and extent of elongation). A discussion of the dependence of the constraint parameter κ on υ2C is given, and is applied to the calculation of stress-strain isotherms in elongation specifically for cis-polyisoprene cured with dicumyl peroxide. The experimental dependence of κ on υ2C investigated by Erman and Mark was found to be similar to the dependence of the plateau modulus on dilution, and this is consistent with the constrained contour model proposed by Erman and Monnerie.

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Characterization of NBR networks from stress–strain and swelling equilibrium measurements

Journal of Applied Polymer Science ◽

10.1002/app.1971.070150803 ◽

1971 ◽

Vol 15 (8) ◽

pp. 1837-1850 ◽

Cited By ~ 6

Author(s):

A. M. Hassan ◽

L. N. Ray

Keyword(s):

Stress Strain ◽

Swelling Equilibrium

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Isolation and Characterization of Plasminogen Activator from Pig Leucocytes

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649147 ◽

1974 ◽

Vol 31 (01) ◽

pp. 072-085 ◽

Cited By ~ 5

Author(s):

M Kopitar ◽

M Stegnar ◽

B Accetto ◽

D Lebez

Keyword(s):

Molecular Weight ◽

Plasminogen Activator ◽

Gel Electrophoresis ◽

Gel Filtration ◽

Ph Optimum ◽

Isolation And Characterization ◽

Ph Range ◽

Inhibition Studies ◽

Final Purification

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.

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Studies on the Characterization of Factor VIII and a Co-factor VIII

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649167 ◽

1974 ◽

Vol 31 (02) ◽

pp. 328-338

Author(s):

M. M. P Paulssen ◽

H. L. M. A Vandenbussche-Scheffers ◽

P. B Spaan ◽

T de Jong ◽

M. C Planje

Keyword(s):

Molecular Weight ◽

Factor Viii ◽

The Body ◽

Haemophilia A ◽

Von Willebrand's Disease ◽

Von Willebrand’S Disease ◽

Polysaccharide Content ◽

Plasma Factor ◽

Two Factors

SummaryFactor VIII occurs in the body in two different forms. In lymph factor VIII is bound to chylomicra. In plasma, factor VIII is bound to a protein.After delipidation of chylomicra we obtained a glycoprotein with a high polysaccharide content and a molecular weight of approx. 160,000.In plasma, factor VIII is attached to a protein which is present in normal concentrations in plasma of patients with haemophilia A and in serum (co-factor VIII).This factor is deficient in both the plasma and the serum of patients with von Willebrand’s disease.The binding between factor VIII and co-factor VIII is reversible.Some properties of these two factors are described.

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Rapid Isolation of High Molecular Weight Urokinase from Native Human Urine

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657167 ◽

1982 ◽

Vol 47 (03) ◽

pp. 197-202 ◽

Cited By ~ 23

Author(s):

Kurt Huber ◽

Johannes Kirchheimer ◽

Bernd R Binder

Keyword(s):

Molecular Weight ◽

High Molecular Weight ◽

Human Urine ◽

Gel Filtration ◽

Chain Structure ◽

The Other ◽

Single Chain ◽

Apparent Homogeneity ◽

Sequential Adsorption

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.

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Prothrombin Metz : Purification and Characterization of a Variant of Human Prothrombin

10.1055/s-0038-1665670 ◽

1979 ◽

Author(s):

M Ribieto ◽

J Elion ◽

D Labie ◽

F Josso

Keyword(s):

Molecular Weight ◽

Gel Electrophoresis ◽

Polyacrylamide Gel Electrophoresis ◽

Factor Xa ◽

Polyacrylamide Gel ◽

Cleavage Pattern ◽

Purification And Characterization ◽

Double Immunodiffusion ◽

The Family

For the purification of the abnormal prothrombin (Pt Metz), advantage has been taken of the existence in the family of three siblings who, being double heterozygotes for Pt Metz and a hypoprothrombinemia, have no normal Pt. Purification procedures included barium citrate adsorption and chromatography on DEAE Sephadex as for normal Pt. As opposed to some other variants (Pt Barcelona and Madrid), Pt Metz elutes as a single symetrical peak. By SDS polyacrylamide gel electrophoresis, this material is homogeneous and appears to have the same molecular weight as normal Pt. Comigration of normal and abnormal Pt in the absence of SDS, shows a double band suggesting an abnormal charge for the variant. Pt Metz exhibits an identity reaction with the control by double immunodiffusion. Upon activation by factor Xa, Pt Metz can generate amydolytic activity on Bz-Phe-Val-Arg-pNa (S2160), but only a very low clotting activity. Clear abnormalities are observed in the cleavage pattern of Pt Metz when monitored by SDS gel electrophoresis. The main feature are the accumulation of prethrombin l (Pl) and the appearance of abnormal intermediates migrating faster than Pl.

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Experimental Characterization of Mechanical Behavior of Cord-Rubber Composites

Tire Science and Technology ◽

10.2346/1.2150974 ◽

1982 ◽

Vol 10 (1) ◽

pp. 37-54 ◽

Cited By ~ 11

Author(s):

M. Kumar ◽

C. W. Bert

Keyword(s):

Response Characteristic ◽

Cord Compression ◽

Complete Characterization ◽

Strain Response ◽

Strain Gages ◽

Experimental Characterization ◽

Rubber Composites ◽

Stress Strain ◽

Strain Data

Abstract Unidirectional cord-rubber specimens in the form of tensile coupons and sandwich beams were used. Using specimens with the cords oriented at 0°, 45°, and 90° to the loading direction and appropriate data reduction, we were able to obtain complete characterization for the in-plane stress-strain response of single-ply, unidirectional cord-rubber composites. All strains were measured by means of liquid mercury strain gages, for which the nonlinear strain response characteristic was obtained by calibration. Stress-strain data were obtained for the cases of both cord tension and cord compression. Materials investigated were aramid-rubber, polyester-rubber, and steel-rubber.

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