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.
A Comment On The T.... Relaxation As Observed In Polymers By Means Of Thermally Stimulated Current (Tsc) Measurements, William Macknight, R. M. Neumann
Dec 1980
A Comment On The T.... Relaxation As Observed In Polymers By Means Of Thermally Stimulated Current (Tsc) Measurements, William Macknight, R. M. Neumann
William MacKnight
No abstract provided.
A Critical Analysis Of The Use Of Sample-Supportive Techniques In The Measurement Of Dynamic Mechanical Relaxation Processes, William Macknight, R. M. Neumann, G. A. Senich
Dec 1977
A Critical Analysis Of The Use Of Sample-Supportive Techniques In The Measurement Of Dynamic Mechanical Relaxation Processes, William Macknight, R. M. Neumann, G. A. Senich
William MacKnight
It is shown that the technique of dynamic spring analysis (DSA) gives rise to a dynamic mechanical loss dispersion well above the glass transition temperature, T0, analogous to the T11 process observed in torsional braid analysis. A mechanical model is proposed which explains why any composite sample consisting of an elastic support coupled to a viscous liquid must necessarily produce such a relaxation regardless of whether the liquid is monomeric or polymeric-in nature. Loss tangent measurements performed on a series of polystyrenes of varying molecular weight and on glycerol using both DSA and a Rheometrics mechanical spectrometer show that the …
Infrared Dichroism Studies Of The Relaxation Of Ethylene-Methacrylic Acid Copolymers And Their Salts, William Macknight, Y. Uemura, R. S. Stein
Dec 1970
Infrared Dichroism Studies Of The Relaxation Of Ethylene-Methacrylic Acid Copolymers And Their Salts, William Macknight, Y. Uemura, R. S. Stein
William MacKnight
The change in infrared dichroism with elongation has been observed at a series of temperatures for several infrared bands of ethylene-methacrylic acid copolymers and their salts. The orientation functions of hydrocarbon and methacrylic acid parts of the molecule were calculated as a function of the temperature of stretching. It is found that the orientation function-strain coefficient for the un-ionized acid decreases uniformly with temperature, but that for the ionized salt passes through a maximum at about 40° where the strain-optical coefficient has been observed to pass through a maximum. Maxima are observed for the dichroism-strain coefficients for both the hydrocarbon …
Birefringence Studies Of The Relaxation Of Ethylene-Methacrylic Acid Copolymers And Their Salts, William Macknight
Dec 1969
Birefringence Studies Of The Relaxation Of Ethylene-Methacrylic Acid Copolymers And Their Salts, William Macknight
William MacKnight
The strain-optical coefficient of ethylene-methacrylic acid copolymers is measured in static and dynamic experiments as a function of temperature and degree of ionization. An alpha optical loss peak which corresponds to a mechanical loss peak is found for the ionized salt but not for the un-ionized acid. This peak is associated with mobility of an ionized domain. Birefringence relaxation curves are found to be superposable using horizontal and vertical shift factors. A plot of the logarithmic shift factor against (1/T) gives a broken curve exhibiting two activation energies for the salt indicating contributions by two processes.
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. …
Chemical Stress Relaxation, William Macknight
Dec 1966
Chemical Stress Relaxation, William Macknight
William MacKnight
No abstract provided.
Relaxation Of Disulfide And Tetrasulfide Polymers, William Macknight, A. V. Tobolsky, M. Takahashi
Dec 1963
Relaxation Of Disulfide And Tetrasulfide Polymers, William Macknight, A. V. Tobolsky, M. Takahashi
William MacKnight
The chemorheology of cross-linked polyethylene disulfide, polyethylene tetrasulfide, and mixtures of these polymers with elemental sulfur is investigated. It is shown that stress decay in the disulfide polymer occurs by scission of the small quantities of higher polysulfide linkages present in the network. It is also shown that elemental sulfur decreases the chemical relaxation time in cross-linked polyethylene disulfide in a predictable manner.
