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Polymer Science Commons™

Open Access. Powered by Scholars. Published by Universities.®

1996

Selected Works

Articles 1 - 7 of 7

Full-Text Articles in Polymer Science

On The Importance Of Chain Reptation In Models Of Dissolution Of Glassy Polymers, Balaji Narasimhan, Nikolaos A. Peppas Jan 1996

On The Importance Of Chain Reptation In Models Of Dissolution Of Glassy Polymers, Balaji Narasimhan, Nikolaos A. Peppas

Balaji Narasimhan

Polymer dissolution was described by chain reptation incorporated into penetrant transport. The penetrant concentration field was divided into three regimes which delineate three different transport processes. Solvent penetration through the polymer was modeled to occur as a consequence of a diffusional flux and an osmotic pressure contribution. Species momentum balances were written that coupled the polymer viscoelastic behavior with the transport mechanism. Transport in the second penetrant concentration regime was modeled to occur in a diffusion boundary layer adjacent to the rubbery-solvent interface, where a Smoluchowski type diffusion equation was obtained. The disentanglement rate of the polymer is given by …

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Dynamic Viscoelastic Properties Of Poly(Ethylene-Propylene) Diblock Copolymer In The Melt State And Solutions, William Macknight, K. Sakurai, D.J. Lohse, D.N. Schulz, J.A. Sissano, W. Wedler, H. H. Winter Dec 1995

Dynamic Viscoelastic Properties Of Poly(Ethylene-Propylene) Diblock Copolymer In The Melt State And Solutions, William Macknight, K. Sakurai, D.J. Lohse, D.N. Schulz, J.A. Sissano, W. Wedler, H. H. Winter

William MacKnight

No abstract provided.

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Structure And Properties Of Polyelectrolyte-Surfactant Nonstoichiometric Complexes In Low-Polarity Solvents, William Macknight, Kirill N. Bakeev, Yang M. Shu, Alexander B. Zezin, Viktor A. Kabanov, Andrey V. Lezov, Alexander B. Mel'nikov, Igor P. Kolomiets, Evgenii I. Rjumtsev Dec 1995

Structure And Properties Of Polyelectrolyte-Surfactant Nonstoichiometric Complexes In Low-Polarity Solvents, William Macknight, Kirill N. Bakeev, Yang M. Shu, Alexander B. Zezin, Viktor A. Kabanov, Andrey V. Lezov, Alexander B. Mel'nikov, Igor P. Kolomiets, Evgenii I. Rjumtsev

William MacKnight

No abstract provided.

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Ionomeric Blends Of Poly(Ethyl Acrylate-Co-4-Vinylpyridine) With Zinc-Neutralized Sulfonated Poly(Ethylene Terephthalate). 3. Effects Of Functionalization Level, William Macknight, C. W. Alice Ng Dec 1995

Ionomeric Blends Of Poly(Ethyl Acrylate-Co-4-Vinylpyridine) With Zinc-Neutralized Sulfonated Poly(Ethylene Terephthalate). 3. Effects Of Functionalization Level, William Macknight, C. W. Alice Ng

William MacKnight

No abstract provided.

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Self-Assembled Complexes Of Synthetic Polypeptides And Oppositely Charged Low Molecular Weight Surfactants. Solid-State Properties, William Macknight, Ekaterina A. Ponomarenko, Alan J. Waddon, Kirill N. Bakeev, David A. Tirrell Dec 1995

Self-Assembled Complexes Of Synthetic Polypeptides And Oppositely Charged Low Molecular Weight Surfactants. Solid-State Properties, William Macknight, Ekaterina A. Ponomarenko, Alan J. Waddon, Kirill N. Bakeev, David A. Tirrell

William MacKnight

Solid-state properties of the stoichiometric complexes formed by sodium poly(a,L-glutamate)
and oppositely charged low molecular weight surfactants (alkyltrimethylammonium bromides) were
examined by circular dichroism, infrared, and X-ray diffraction techniques. The polypeptide chains in
the complexes were shown to be predominantly in the a-helical conformation at room temperature. At
higher temperatures, weakening or disruption of intramolecular hydrogen bonds stabilizing the a-helical
conformation was observed. The polypeptide-surfactant complexes were shown to adopt lamellar
structures in the temperature range 20-150 °C. The lamellae consist of alternating layers of
polyglutamate chains and bimolecular layers of surfactant, with the surfactant alkyl chains aligned
perpendicular to …

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Ionomeric Blends Of Poly(Ethyl Acrylate-Co-4-Vinylpyridine) With Metal-Neutralized Sulfonated Poly(Ethylene Terephthalate). 4. Effects Of Counterions, William Macknight Dec 1995

Ionomeric Blends Of Poly(Ethyl Acrylate-Co-4-Vinylpyridine) With Metal-Neutralized Sulfonated Poly(Ethylene Terephthalate). 4. Effects Of Counterions, William Macknight

William MacKnight

No abstract provided.

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Blends Of Amorphous-Crystalline Block Copolymers With Amorphous Homopolymers. Morphological Studies By Electron Microscopy And Small Angle Scattering, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano, Jar-Shyoung Lin, Mikhail Agamalyan Dec 1995

Blends Of Amorphous-Crystalline Block Copolymers With Amorphous Homopolymers. Morphological Studies By Electron Microscopy And Small Angle Scattering, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano, Jar-Shyoung Lin, Mikhail Agamalyan

William MacKnight

A morphological study was performed with symmetric diblock ethylene-propylene copolymer (DEP) and
the binary blends made from DEP and atactic polypropylene (APP) by use of small angle X-ray, light
and neutron scattering, and also scanning and transmission electron microscopy. DEP contains
a crystallizable polyethylene block and an amorphous atactic polypropylene block. Quenching the blends
in liquid nitrogen preserved the morphology in the melt state. This quenching technique revealed that DEP
forms a lamellar microdomain structure and blending DEP and APP includes morphological changes in the
microdomain structures as well as macrophase separation. When the APP chain was shorter than the …

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