Results 251 to 260 of about 28,638 (302)

Crystallization and Melting of Poly(Oxyethylene) Analyzed by Temperature-Modulated Calorimetry

Journal of Polymer Science, Part B: Polymer Physics, 1997
Temperature-modulated calorimetry, TMC, is used to evaluate the temperature region of metastability between crystallization and melting. While crystals like indium can be made to melt practically reversibly during a TMC cycle of low amplitude so that sufficient crystal nuclei remain unmelted, linear macromolecules cannot, because of their need to ...
Bernhard Wunderlich
exaly   +2 more sources

Influence of the Temperature of Crystallization on the Melting of Crystalline Rubber

Rubber Chemistry and Technology, 1941
Abstract Data presented in this communication show an instance in which melting of a crystalline material is very much dependent on the temperature at which the crystals have been formed. It is well known that many substances in which crystallization is relatively slow can be crystallized at different temperatures in a range below the melting ...
Norman Bekkedahl, Lawrence A. Wood
openaire   +2 more sources

The crystallization and melting of copolymers I—The effect of the crystallization temperature upon the apparent melting temperature of polymethylene copolymers

Polymer, 1966
The apparent melting temperatures for a series of polymethylene copolymers were determined as a function of crystallization temperature and level of crystallinity. The copolymers contained from 1·2 to 6·4 mole per cent of either methyl or n -propyl side groups arranged in random sequence distribution.
C.H. Baker, L. Mandelkern
openaire   +1 more source

Melting the Ice: On the Relation between Melting Temperature and Size for Nanoscale Ice Crystals

ACS Nano, 2011
Although the melting of ice is an everyday process, important issues remain unclear particularly on the nanoscale. Indeed despite extensive studies into ice melting and premelting, little is known about the relationship between (pre)melting and crystal size and morphology, with, for example, the melting temperature of ice nanocrystals being unclear ...
Pan, Ding, Liu, Limin, Slater, Ben J., Michaelides, Angelos, Wang, Ee Ge   +4 more
openaire   +3 more sources

Effect of atmosphere on the crystallization temperature of BaB2O4 melt

Journal of Crystal Growth, 2001
Abstract The differential thermal analysis (DTA) on BaB 2 O 4 (BBO) single crystals and polycrystalline material has been performed under both oxidising and inert atmospheres. The melt under oxygen is found to supercool down to 966°C, while under argon the crystallization temperature is further lowered to 887°C. This novel observation has been found
. Sangeeta, S.C. Sabharwal
openaire   +1 more source

Melt temperature effects on the polymorphic behaviour of melt-crystallized polypivalolactone

Polymer, 1994
Abstract Experimental evidence is discussed indicating that in the case of polypivalolactone (PPVL), the time spent in the melt, and the melt temperature from which the samples are quenched to the crystallization temperature, both affect the subsequent crystallization process, and specifically the relative proportions of the α- and γ-modifications ...
openaire   +1 more source

Influence of the melt temperature on the thermoplastics crystallization process

Polymer Bulletin, 1990
The influence of the melt temperature (T1) on the crystallization kinetics and the morphology of two semicrystalline polymers: poly(oxymethylene): Tm0=198° C and poly(ether-ether-ketone) Tm0=380° C) was investigated using thermal analysis and optical microscopy.
A. Franbourg, F. Rietsch
openaire   +1 more source

The effect of melt temperature on nucleation in crystallizing polymers

Die Makromolekulare Chemie, 1963
Abstract A study has been made of the temperature dependence of the nucleation process in poly(ethylene oxide), and also of the related bulk crystallization rate determined from dilatometric experiments. Variations in these quantities were found, both above and below the melting point, and these are discussed in relation to current ...
W. Banks, A. Sharples
openaire   +1 more source

Relationship between crystallization temperature and melting temperature in crystalline materials

Journal of Materials Science, 1990
The ratio of the absolute temperature at which the homogeneous nucleation rate or the crystal growth rate is maximum (Tcmax) to the absolute melting temperature (Tm) is analysed by two parameters: one is the ratio of the activation energy for migration (ΔE) and the heat of fusion (ΔHm), the other is the ratio of mean molar surface energy\(\left( {\bar \
openaire   +1 more source

Pre‐melting temperature effect on the isothermal melt crystallization and multiple melting behavior of syndiotactic polystyrene

Polymer Engineering & Science, 2001
AbstractThis work examined how pre‐melting temperature (Tmax) affects the isothermal melt crystallization kinetics, the resulting melting behavior and crystal structure of syndiotactic polystyrene (sPS) by using differential scanning calorimetry (DSC), polarized light microscopy (PLM) and the wide angle X‐ray diffraction (WAXD) technique.
Fang‐chyou Chiu, Kuan‐yeu Shen, Stanley H. Y. Tsai, Chien‐ming Chen   +3 more
openaire   +1 more source