Measurement of the Heat of Fusion of Crystalline Polymers by a Calorimetric Melting Point Depression Technique

1968 ◽  
pp. 9-14 ◽  
Author(s):  
J. R. Knox
Keyword(s):  
Melting Point ◽  
Melting Point Depression ◽  
Heat Of Fusion ◽  
Crystalline Polymers

scholarly journals Stress-Generated Ice Crystals in a Nearly Isothermal Two-Phase System

1968 ◽  
Vol 7 (50) ◽  
pp. 183-198 ◽  
Author(s):  
E. LaChapelle
Keyword(s):  
Melting Point ◽  
Hydrostatic Stress ◽  
Ice Crystals ◽  
Melting Point Depression ◽  
Heat Of Fusion ◽  
Phase System ◽  
Two Phase ◽  
History Of ◽  
Pressure Melting ◽  
Ice Water

The use of the two-phase system ice–water to illustrate the effects on equilibrium of both hydrostatic and non-hydrostatic stresses has been a recurrent theme in the history of thermodynamic theory. The effects of hydrostatic pressure on the melting point of ice are firmly established by theory and experiment. Those of non-hydrostatic stress are still a subject of debate today; several theorists have predicted ice re-crystallization under such stress, but the magnitude of any slight melting-point depression is not known with certainty. The recrystallization of ice caused by local variations in hydrostatic stress was predicted and experimentally confirmed over a century ago. Cavities deep within temperate glaciers provide a suitable environment for the occurrence of this latter phenomenon. A water-filled cavity intersected by a tunnel in nearly stagnant ice of the Blue Glacier, Washington State, U.S.A., was lined with large and unusual single ice crystals which apparently owe their origin to the effects of hydrostatic stress. Even the minute differences in pressure melting point around this cavity are adequate to remove the heat of fusion as ice forms within it. There is evidence that interstitial movement of melt water in the surrounding ice also contributes to the heat and mass transfer. The form of these crystals indicates that they grew into slightly supercooled water. It is suggested that this growth pattern is sustained by the existence of oriented stresses at the cavity walls.

scholarly journals Stress-Generated Ice Crystals in a Nearly Isothermal Two-Phase System

1968 ◽  
Vol 7 (50) ◽  
pp. 183-198 ◽  
Author(s):  
E. LaChapelle
Keyword(s):  
Melting Point ◽  
Hydrostatic Stress ◽  
Ice Crystals ◽  
Melting Point Depression ◽  
Heat Of Fusion ◽  
Phase System ◽  
Two Phase ◽  
History Of ◽  
Pressure Melting ◽  
Ice Water

The use of the two-phase system ice–water to illustrate the effects on equilibrium of both hydrostatic and non-hydrostatic stresses has been a recurrent theme in the history of thermodynamic theory. The effects of hydrostatic pressure on the melting point of ice are firmly established by theory and experiment. Those of non-hydrostatic stress are still a subject of debate today; several theorists have predicted ice re-crystallization under such stress, but the magnitude of any slight melting-point depression is not known with certainty. The recrystallization of ice caused by local variations in hydrostatic stress was predicted and experimentally confirmed over a century ago. Cavities deep within temperate glaciers provide a suitable environment for the occurrence of this latter phenomenon. A water-filled cavity intersected by a tunnel in nearly stagnant ice of the Blue Glacier, Washington State, U.S.A., was lined with large and unusual single ice crystals which apparently owe their origin to the effects of hydrostatic stress. Even the minute differences in pressure melting point around this cavity are adequate to remove the heat of fusion as ice forms within it. There is evidence that interstitial movement of melt water in the surrounding ice also contributes to the heat and mass transfer. The form of these crystals indicates that they grew into slightly supercooled water. It is suggested that this growth pattern is sustained by the existence of oriented stresses at the cavity walls.

scholarly journals Heat of fusion of nylon-12 from melting point depression by methoxymethylation.

1989 ◽  
Vol 45 (7) ◽  
pp. 307-309
Author(s):  
Nobuyuki Tanaka ◽  
Yukio Abe ◽  
Kazumitsu Tamura
Keyword(s):  
Melting Point ◽  
Melting Point Depression ◽  
Heat Of Fusion ◽  
Nylon 12

Melting point depression in poly(butylene terephthalate)/polyarylate blends

1993 ◽  
Vol 26 (12) ◽  
pp. 3127-3130 ◽  
Author(s):  
Peter P. Huo ◽  
Peggy Cebe
Keyword(s):  
Melting Point ◽  
Melting Point Depression ◽  
Butylene Terephthalate

Melting point depression study of polyacrylonitrile

1960 ◽  
Vol 43 (142) ◽  
pp. 467-488 ◽  
Author(s):  
W. R. Krigbaum ◽  
Noboru Tokita
Keyword(s):  
Melting Point ◽  
Melting Point Depression

Standard enthalpy of fusion of N,N′-ethylenebis (2,4-pentanedion-iminoato)nickel(II) complex by DTA-based melting point depression studies

2005 ◽  
Vol 59 (11) ◽  
pp. 1334-1337 ◽  
Author(s):  
S. Arockiasamy ◽  
P. Antony Premkumar ◽  
O.M. Sreedharan ◽  
C. Mallika ◽  
V.S. Raghunathan ◽  
...  
Keyword(s):  
Melting Point ◽  
Standard Enthalpy ◽  
Enthalpy Of Fusion ◽  
Melting Point Depression

Evaluation of Color Additives Using a Differential Scanning Calorimeter

1970 ◽  
Vol 53 (2) ◽  
pp. 244-249
Author(s):  
Daniel M Marmion
Keyword(s):  
Melting Point ◽  
Moisture Content ◽  
Differential Scanning Calorimeter ◽  
Relative Stability ◽  
Heat Of Fusion ◽  
Permanent Record ◽  
Natural Color ◽  
Sensitive Tool ◽  
Similar Information

Abstract DSC is a rapid and sensitive tool for the determination of the melting point, moisture content, purity, and heat of fusion of certifiable colors. The relative stability and the identification of the colorants may also be deduced from the thermograms. The procedures outlined require only a few milligrams of sample and provide a permanent record. Attempts to obtain similar information for natural color additives were unsuccessful due to the inability to obtain reproducible thermograms.

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