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William MacKnight

Selected Works

Polyurethanes

Articles 1 - 8 of 8

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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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Transport-Morphology Relationships In Segmented Polybutadiene Polyurethanes: 2. Analysis, William Macknight, Myrna Serrano, Edwin L. Thomas, J Dottino Dec 1986

Transport-Morphology Relationships In Segmented Polybutadiene Polyurethanes: 2. Analysis, William Macknight, Myrna Serrano, Edwin L. Thomas, J Dottino

William MacKnight

No abstract provided.

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Structure And Properties Of Polybutadiene Polyurethanes, William Macknight, N. S. Schneider, C. M. Brunette, S. L. Hsu Dec 1980

Structure And Properties Of Polybutadiene Polyurethanes, William Macknight, N. S. Schneider, C. M. Brunette, S. L. Hsu

William MacKnight

No abstract provided.

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Thermal And Mechanical Properties Of Linear Segmented Polyurethanes With Butadiene Soft Segments, William Macknight, C. M. Brunette, S. L. Hsu, M. Rossman, N. S. Schneider Dec 1980

Thermal And Mechanical Properties Of Linear Segmented Polyurethanes With Butadiene Soft Segments, William Macknight, C. M. Brunette, S. L. Hsu, M. Rossman, N. S. Schneider

William MacKnight

No abstract provided.

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Structural And Mechanical Properties Of Polybutadiene-Containing Polyurethanes, William Macknight, C. M. Brunette, S. L. Hsu, N. S. Schneider Dec 1980

Structural And Mechanical Properties Of Polybutadiene-Containing Polyurethanes, William Macknight, C. M. Brunette, S. L. Hsu, N. S. Schneider

William MacKnight

No abstract provided.

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Property-Structure Relationships In Poly-Urethanes: Infrared Studies, William Macknight, M. Yang Dec 1972

Property-Structure Relationships In Poly-Urethanes: Infrared Studies, William Macknight, M. Yang

William MacKnight

No abstract provided.

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Thermal Properties Of Polyurethanes. Enthalpies And Entropies Of Fusion, William Macknight, T. Kajiyama Dec 1969

Thermal Properties Of Polyurethanes. Enthalpies And Entropies Of Fusion, William Macknight, T. Kajiyama

William MacKnight

Enthalpies and entropies of fusion have been determined for two series of scmicrystalline polyurethanes. The H series is based on 1,6-hexamethylene diiso­cyanate and various a, 01-diols containing from 2 to 10 methylene units. The DP series is based on 4,4'-methylene diphenyl diisocyanate and various a, m-diols containing from 2 to 10 methylene units. Differential Scanning Calorimetry (DSC) was used in con­j unction with X-ray analysis (X-ray method) and low molecular-weight diluents (diluent method) to determine the enthalpies of fusion. Agreement between the X-ray method and the diluent method was good. 
Differences between the enthalpies and entropies of fusion of the …

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Relaxation In Polyurethanes In The Glass Transition Region, William Macknight, T. Kajiyama Dec 1968

Relaxation In Polyurethanes In The Glass Transition Region, William Macknight, T. Kajiyama

William MacKnight

A study has been made of the relaxation phenomena in three series of poly­urethanes in the neighborhood of their glass transition temperatures and above. The technique of dynamic mechanical relaxation was used in the investigation at various frequencies up to 110 Hz. Differential Scanning Calorimetry (DSC) was also used as a supplement to the mechanical measurements. The series are: (1) H series based on polymerization of hexamethylene diisocyanate and various diols, (2) DP series based on polymerization of 4,4' diphenylmethane diisocyanate and various diols, and (3) 4M series based on polymerization of 4-methyl meta pheny lene diisocyanate and various diols. …

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