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Chemical Engineering

William MacKnight

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Full-Text Articles in Engineering

Spherulite Formation From Microphase-Separated Lamellae In Semi-Crystalline Diblock Copolymer Comprising Polyethylene And Atactic Polypropylene Blocks, William Macknight, Masaya Ueda, Kazuo Sakurai, Shigeru Okamoto, David J. Lohse, Seiji Shinkai, Shinichi Sakurai, Shunji Nomura Dec 2002

Spherulite Formation From Microphase-Separated Lamellae In Semi-Crystalline Diblock Copolymer Comprising Polyethylene And Atactic Polypropylene Blocks, William Macknight, Masaya Ueda, Kazuo Sakurai, Shigeru Okamoto, David J. Lohse, Seiji Shinkai, Shinichi Sakurai, Shunji Nomura

William MacKnight

No abstract provided.

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Blending Of Immiscible Polymers In A Mixing Zone Of A Twin Screw Extruder- Effects Of Compatibilization, William Macknight, O. Franzheim, T. Rische, M. Stephan Dec 1999

Blending Of Immiscible Polymers In A Mixing Zone Of A Twin Screw Extruder- Effects Of Compatibilization, William Macknight, O. Franzheim, T. Rische, M. Stephan

William MacKnight

The dependence of the morphology development of physical as well as of reactive
compatibilized polypropylene/polyamide 6 (PP /PA6) blends in a mixing zone of a
co-rotating twin screw extruder on blend composition and screw rotational speed
was investigated. A special process analytical set-up based on a co-rotating twin
screw extruder was used, which allowed melt sampling from different positions
along the operating extruder in time periods less than 10 seconds. It has been
shown that the disperse particle sizes in physical blends depend crucially on the
blend composition because of the increasing influence of coalescence with an increasing
concentration of …

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Miscibility And Characterization Of The Ternary Crystalline System: Poly(Vinyl Butyral)/Poly(Vinyl Alcohol)/Nylon6, William Macknight, H. Jeong, M. Rooney, D. J. David, F. E. Karasz, T. Kajiyama Dec 1999

Miscibility And Characterization Of The Ternary Crystalline System: Poly(Vinyl Butyral)/Poly(Vinyl Alcohol)/Nylon6, William Macknight, H. Jeong, M. Rooney, D. J. David, F. E. Karasz, T. Kajiyama

William MacKnight

No abstract provided.

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Miscibility Of Polyvinyl Butyral/Nylon 6 Blends, William Macknight, H. Jeong, M. Rooney, D. J. David, F. E. Karasz, T. Kajiyama Dec 1999

Miscibility Of Polyvinyl Butyral/Nylon 6 Blends, William Macknight, H. Jeong, M. Rooney, D. J. David, F. E. Karasz, T. Kajiyama

William MacKnight

No abstract provided.

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Phase Behaviour In Blends Of Poly[Styrene-Co-Ortho(Para)-Bromostyrene] And Phenylsulfonated Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Copolymers, William Macknight, R. Vukovic, G. Bogdanic, A. Erceg, D. Fles, F. E. Karasz Dec 1997

Phase Behaviour In Blends Of Poly[Styrene-Co-Ortho(Para)-Bromostyrene] And Phenylsulfonated Poly(2,6-Dimethyl-1,4-Phenylene Oxide) Copolymers, William Macknight, R. Vukovic, G. Bogdanic, A. Erceg, D. Fles, F. E. Karasz

William MacKnight

Random copolymers of styrene with ortho- or para-bromostyrene differ substantially in their blend behaviour with partly sulfonylated poly(2,6-dimethyl-l,4-phenylene oxide) (SPPO). Copolymers of styrene with ortho­bromostyrene exhibit a very narrow window of miscibility in comparison with styrene-para-bromostyrene copolymer blends with SPPOs. The experimental results can be accounted for on the basis of individual segmental interaction parameters by applying mean-field theory.

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Thermally Stable Silphenylene Vinyl Siloxane Elastomers And Their Blends, William Macknight, H. Dennis Zhu, Simon W. Kantor Dec 1997

Thermally Stable Silphenylene Vinyl Siloxane Elastomers And Their Blends, William Macknight, H. Dennis Zhu, Simon W. Kantor

William MacKnight

No abstract provided.

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Water-Insoluble Complexes Of Poly(L-Lysine) With Mixed Alkyl Sulfates: Composition-Controlled Solid State Structures, William Macknight, Ekaterina A. Ponomarenko, David A. Tirrell Dec 1997

Water-Insoluble Complexes Of Poly(L-Lysine) With Mixed Alkyl Sulfates: Composition-Controlled Solid State Structures, William Macknight, Ekaterina A. Ponomarenko, David A. Tirrell

William MacKnight

Structures of the water-insoluble complexes of poly(L-lysine) with octyl and octadedecyl
sulfates, and with the mixtures of these surfactants, were examined via X-ray diffraction, infrared
spectroscopy, and differential scanning calorimetry. The solid-state structures of the complexes were
shown to be governed by their compositions. In the stoichiometric poly(L-lysine) complex with octadecyl
sulfate, surfactant chains crystallize on a hexagonal lattice. In the poly(L-lysine)-octyl sulfate complex
of nearly stoichiometric composition, the surfactants are arranged on an alkane-type two-dimensional
lattice. In the complex with 20 mol % octadecyl sulfate and about 75 mol % octyl sulfate, the longer
surfactant chains form hexagonal crystalline …

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Self-Assembled Polyelectrolyte-Surfactant Complexes In Nonaqueous Solvents And In The Solid State, William Macknight, Ekaterina A. Ponomarenko, David A. Tirrell Dec 1997

Self-Assembled Polyelectrolyte-Surfactant Complexes In Nonaqueous Solvents And In The Solid State, William Macknight, Ekaterina A. Ponomarenko, David A. Tirrell

William MacKnight

No abstract provided.

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End-Group Effect On Chain Conformation Of Poly(Propylene Glycol) And Poly(Ethylene Glycol), William Macknight, Sunghoe Yoon, Shaw Ling Hsu Dec 1996

End-Group Effect On Chain Conformation Of Poly(Propylene Glycol) And Poly(Ethylene Glycol), William Macknight, Sunghoe Yoon, Shaw Ling Hsu

William MacKnight

No abstract provided.

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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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Effects Of Water On The Mechanical Relaxation In Polyamide 4, William Macknight, M. A. Bellinger, C.-W.A. Ng Dec 1994

Effects Of Water On The Mechanical Relaxation In Polyamide 4, William Macknight, M. A. Bellinger, C.-W.A. Ng

William MacKnight

No abstract provided.

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Spectroscopic Analysis Of Chain Conformation Distribution In A Biodegradable Polyester Elastomer, Poly(Beta-Hydroxyoctanoate), William Macknight, Hun Jan Tao, K. D. Gagnon, R. W. Lenz, Shaw L. Hsu Dec 1994

Spectroscopic Analysis Of Chain Conformation Distribution In A Biodegradable Polyester Elastomer, Poly(Beta-Hydroxyoctanoate), William Macknight, Hun Jan Tao, K. D. Gagnon, R. W. Lenz, Shaw L. Hsu

William MacKnight

Chain conformational distribution of a biodegradable polyester elastomer, poly(p-hydroxy­octanoate) (PHO), has been analyzed using vibrational spectroscopy in conjunction with normal vibrational analysis. For the as-prepared, mainly amorphous materials, side-chain conformation distribution is extremely broad and is consistent with the expected three-state rotational isomeric model. On the basis of our vibrational analysis, we have established that side-chain conformational distribution transforms to one containing mainly the extended form after thermal annealing. In contrast, the conformational distribution of the side chains remains unchanged as a function of strain. Additionally, the carbonyl stretching vibrations were found to be sensitive to changes in the crystalline …

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Segmented Polyurethane Elastomers With Liquid Crystalline Hard Segments. 3. Infrared Spectroscopic Study, William Macknight, Weiming Tang, Shaw L. Hsu Dec 1994

Segmented Polyurethane Elastomers With Liquid Crystalline Hard Segments. 3. Infrared Spectroscopic Study, William Macknight, Weiming Tang, Shaw L. Hsu

William MacKnight

Segmented liquid crystalline polyurethanes (LCPUE) have been studied by infrared
spectroscopy. The nematic liquid crystalline hard domains act as physical cross-links and can be oriented
by the application of mechanical strain. The orientation function achievable in the hard segments results
from the combination of mechanical strain and stress-softening. Furthermore, elastic deformation induces
the rearrangement of some hard segments in the mesophase into a more ordered packing. Hightemperature
infrared spectra have been correlated with thermal transitions of the LCPUE, and a liquidliquid
microphase-separated morphology above the isotropization of the mesophase appears to exist.

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Topological Effects On Blend Miscibility, William Macknight, W. L. Nachlis, J. T. Bendler, Roger P. Kambour Dec 1994

Topological Effects On Blend Miscibility, William Macknight, W. L. Nachlis, J. T. Bendler, Roger P. Kambour

William MacKnight

No abstract provided.

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Complexation Of Ionomers And Surfactant Molecules Of The Same Charge In A Nonpolar Solvent, William Macknight, Kirill N. Bakeev, Sergey A. Chugunov, Iwao Teraoka, Alexander B. Zezin, Victor A. Kabanov Dec 1993

Complexation Of Ionomers And Surfactant Molecules Of The Same Charge In A Nonpolar Solvent, William Macknight, Kirill N. Bakeev, Sergey A. Chugunov, Iwao Teraoka, Alexander B. Zezin, Victor A. Kabanov

William MacKnight

Complexation between sulfonated polystyrene ionomers and bis(2-ethylhexyl) sulfosuccinate
sodium salt (aerosol OT, AOT) surfactant molecules in m-xylene was studied by ultracentrifugation, vapor
pressure osmometry, viscometry, and dynamic light scattering. When the dilute ionomer solution is mixed
with the AOT soluti6n, complexation takes place for both the slightly aggregated state of AOT and reversed
micelles of AOT containing water. In the presence of excess AOT molecules, some of the AOT are free from
the ionomers, and there are well-defined limiting compositions for complexes of the ionomer and AOT and
for those of the ionomer and AOT micelles. The limiting composition depends …

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Dynamic Mechanical And Spectroscopic Study Of Ionomer Blends Based On Carboxylated Or Sulfonated Flexible Polystyrene And Rigid Poly(Diacetylenes) With Functional Side Groups, William Macknight, C. D. Eisenbach, J. Hofmann Dec 1993

Dynamic Mechanical And Spectroscopic Study Of Ionomer Blends Based On Carboxylated Or Sulfonated Flexible Polystyrene And Rigid Poly(Diacetylenes) With Functional Side Groups, William Macknight, C. D. Eisenbach, J. Hofmann

William MacKnight

The dynamic mechanical and infrared spectroscopic investigation of ionomer blends of poly-
(diacety1ene)-a nd polystyrene-based ionomers has shown that miscibility of this usually incompatible polymer
pair can be achieved through ion-ion interactions between the blend components. Microphase separation
is prevented through ionic contacts generated during the blend formation; a schematic model of mixing in
the blends is proposed.

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Compatibility Enhancement Of Blends Of Nylon 4 With Lithium-Neutralized Sulfonated Polystyrene, William Macknight, C. -W. Alice Ng, Michelle A. Bellinger Dec 1993

Compatibility Enhancement Of Blends Of Nylon 4 With Lithium-Neutralized Sulfonated Polystyrene, William Macknight, C. -W. Alice Ng, Michelle A. Bellinger

William MacKnight

No abstract provided.

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Blends Of Amorphous-Crystalline Block Copolymers With Amorphous Homopolymers. 2. Synthesis And Characterization Of Poly(Ethylene-Propylene) Diblock Copolymer And Crystallization Kinetics For The Blend With Atactic Polypropylene, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano Dec 1993

Blends Of Amorphous-Crystalline Block Copolymers With Amorphous Homopolymers. 2. Synthesis And Characterization Of Poly(Ethylene-Propylene) Diblock Copolymer And Crystallization Kinetics For The Blend With Atactic Polypropylene, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano

William MacKnight

No abstract provided.

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Application Of A Molecular Simulation Technique For Prediction Of Phase-Separated Structures Of Semirigrid Model Polyurethanes, William Macknight, Hun-Jan Tao, Cun F. Fan, Shaw L. Hsu Dec 1993

Application Of A Molecular Simulation Technique For Prediction Of Phase-Separated Structures Of Semirigrid Model Polyurethanes, William Macknight, Hun-Jan Tao, Cun F. Fan, Shaw L. Hsu

William MacKnight

A combination of a molecular simulation method and the Monte Carlo method has been
succe88fully utilizedto calculate phase diagrams of model polyurethanes. In our model, the entropic contribution
of the Flory-Huggins expression has been modified to incorporate the contribution arising from orientation
of hard segments. The constraint associated with chain rigidity of hard segments has been explicitly considered.
In addition, the interaction term has been modified to include the relative packing of hard segments. Phase
diagrams of various MDI-PPG model polyurethanes have thus been predicted utihhg these modifications.
The effecta of soft- and hard-segment lengths have been considered and the …

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Phase Behavior In Copolymer Blends Of Poly(P-Chlorostyrene-Co-O-Chlorostyrene) And Phenylsulfonylated Poly(2,6-Dimethyl-1,4-Phenylene Oxide), William Macknight, R. Vukovic, G. Bogdanic, Vjera Kuresevic, M. Tomaskovic, F. E. Karasz Dec 1993

Phase Behavior In Copolymer Blends Of Poly(P-Chlorostyrene-Co-O-Chlorostyrene) And Phenylsulfonylated Poly(2,6-Dimethyl-1,4-Phenylene Oxide), William Macknight, R. Vukovic, G. Bogdanic, Vjera Kuresevic, M. Tomaskovic, F. E. Karasz

William MacKnight

The miscibility of random copolymers of o-chlorostyrene and p -chlorostyrene [ P (oC1Stco-
pC1St)] with partially phenylsulfonylated poly (2,6-dimethyl-1,4-phenylenoex ide)
( SPPO) copolymers has been studied, using differential scanning calorimetry (DSC) to
establish Tg behavior. It already has been established that the isomeric effect of the chlorine
substitution on miscibility is large. Thus the para-chloro-substituted styrenic homopolymer
is miscible with all SPPOs containing more than - 5 mol % phenylsulfonylation, whereas
the ortho-chloro-substituted homopolymer is immiscible with the entire range of SPPO
copolymer compositions (and also with the respective homopolymers) . As a result of this
asymmetric behavior of the …

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Structure And Morphology Of Nylon 4 Chain-Folded Lamellar Crystals, William Macknight, M. A. Bellinger, Alan J. Waddon, E. D. T. Atkins Dec 1993

Structure And Morphology Of Nylon 4 Chain-Folded Lamellar Crystals, William Macknight, M. A. Bellinger, Alan J. Waddon, E. D. T. Atkins

William MacKnight

No abstract provided.

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Thermal Degradation Of Segmented Polyurethanes, William Macknight, Zoran S. Petrovic, Zoltan Zavargo, Joseph H. Flynn Dec 1993

Thermal Degradation Of Segmented Polyurethanes, William Macknight, Zoran S. Petrovic, Zoltan Zavargo, Joseph H. Flynn

William MacKnight

Thermal degradation of polyurethane samples was studied by a thermogravimetric method. The effect of soft-segment length and soft-segment concentration on activation energy of the degradation process was measured. Three methods of calculation gave activation energies at different stages of the very complex weight loss process. It was shown that at initial stages of the weight loss the process was dominated by hard-segment degradation. Activation energy of the whole process calculated by the Ozawa-Flynn method did not offer clear insight into the structure-stability relationship of polyurethanes. The second method showed that activation energy of the initial stage of degradation increased with …

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Viscoelastic And Morphological Study Of Ionic Aggregates In Ionomers And Ionomer Blends, William Macknight, Elliot P. Douglas, Alan J. Waddon Dec 1993

Viscoelastic And Morphological Study Of Ionic Aggregates In Ionomers And Ionomer Blends, William Macknight, Elliot P. Douglas, Alan J. Waddon

William MacKnight

No abstract provided.

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Intramolecular Interactions In Poly(Styrene-Co-Acrylonitrile)/Poly(Epsilon-Caprolactone) Blends.Pdf, William Macknight, V. Janarthanan, J. Kressler, F. E. Karasz Dec 1992

Intramolecular Interactions In Poly(Styrene-Co-Acrylonitrile)/Poly(Epsilon-Caprolactone) Blends.Pdf, William Macknight, V. Janarthanan, J. Kressler, F. E. Karasz

William MacKnight

No abstract provided.

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Amorphous-Crystalline Block Copolymer And Amorphous Homopolymer Blends. 1. A Preliminary Report, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano Dec 1992

Amorphous-Crystalline Block Copolymer And Amorphous Homopolymer Blends. 1. A Preliminary Report, William Macknight, Kazuo Sakurai, David J. Lohse, Donald N. Schulz, J.A. Sissano

William MacKnight

No abstract provided.

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