scholarly journals Melting Temperature of Thermally Reversible Gel. V. Heat of Fusion of Cellulose Triacetate and the Melting of Cellulose Diacetate–Benzyl Alcohol Gel

1979 ◽  
Vol 11 (8) ◽  
pp. 671-675 ◽  
Author(s):  
Akira Takahashi ◽  
Toyoharu Kawaharada ◽  
Tadaya Kato
Keyword(s):  
Benzyl Alcohol ◽  
Melting Temperature ◽  
Cellulose Triacetate ◽  
Heat Of Fusion ◽  
Cellulose Diacetate ◽  
Reversible Gel

ChemInform Abstract: Pressure Dependence of the Heat of Fusion and Melting Temperature of Indium.

ChemInform ◽  
2010 ◽  
Vol 27 (28) ◽  
pp. no-no
Author(s):  
G. W. H. HOEHNE ◽  
W. DOLLHOPF ◽  
K. BLANKENHORN ◽  
P. U. MAYR
Keyword(s):  
Melting Temperature ◽  
Pressure Dependence ◽  
Heat Of Fusion

scholarly journals Production of Cellulosic Polymers from Agricultural Wastes

2008 ◽  
Vol 5 (1) ◽  
pp. 81-85 ◽  
Author(s):  
A. U. Israel ◽  
I. B. Obot ◽  
S. A. Umoren ◽  
V. Mkpenie ◽  
J. E. Asuquo
Keyword(s):  
Cocos Nucifera ◽  
Cellulose Triacetate ◽  
Agricultural Wastes ◽  
Pulp Yield ◽  
Cellulose Derivatives ◽  
Cellulose Diacetate ◽  
Ethanoic Acid ◽  
Bamboo Pulp ◽  
Cellulosic Polymers ◽  
Soda Pulping

Cellulosic polymers namely cellulose, di-and triacetate were produced from fourteen agricultural wastes; Branch and fiber after oil extraction from oil palm(Elais guineensis), raffia, piassava, bamboo pulp, bamboo bark from raphia palm(Raphia hookeri), stem and cob of maize plant(Zea mays), fruit fiber from coconut fruit(Cocos nucifera), sawdusts from cotton tree(Cossypium hirsutum), pear wood(Manilkara obovata), stem of Southern gamba green (Andropogon tectorus), sugarcane baggase(Saccharium officinarum)and plantain stem (Musa paradisiaca). They were subjected to soda pulping and hypochlorite bleaching system. Results obtained show that pulp yield from these materials were: 70.00, 39.59, 55.40, 86.00, 84.60, 80.00, 40.84, 81.67, 35.70, 69.11, 4.54, 47.19, 31.70 and 52.44% respectively. The pulps were acetylated with acetic anhydride in ethanoic acid catalyzed by conc. H2SO4 to obtain cellulose derivatives (Cellulose diacetate and triacetate). The cellulose diacetate yields were 41.20, 17.85, 23.13, 20.80, 20.23, 20.00, 39.00, 44.00, 18.80, 20.75, 20.03, 41.20, 44.00, and 39.00% respectively while the results obtained as average of four determinations for cellulose triacetate yields were: 52.00, 51.00, 43.10, 46.60, 49.00, 35.00, 40.60, 54.00, 57.50, 62.52, 35.70. 52.00, 53.00 and 38.70% respectively for all the agricultural wastes utilized. The presence of these cellulose derivatives was confirmed by a solubility test in acetone and chloroform.

Thermodynamics of Crystallization in High Polymers. Natural Rubber

1955 ◽  
Vol 28 (3) ◽  
pp. 718-727 ◽  
Author(s):  
Donald E. Roberts ◽  
Leo Mandelkern
Keyword(s):  
Natural Rubber ◽  
Melting Temperature ◽  
Low Temperatures ◽  
Rapid Heating ◽  
Heat Of Fusion ◽  
Low Molecular Weight ◽  
Heating Rates ◽  
Equilibrium Melting Temperature ◽  
Clapeyron Equation ◽  
Melting Temperatures

Abstract The existence of an equilibrium melting temperature, T0m, at 28 ± 1°, for unstretched natural rubber has been established, using dilatometric methods. The lower melting temperatures previously observed are a consequence of the low temperatures of crystallization and the rapid heating rates employed. From melting point studies of mixtures of the polymer with low molecular-weight diluents, the heat of fusion per repeating unit, ΔHu has been evaluated as 15.3 ± 0.5 cal./g. The values of ΔHu and T0m have then been combined with data of other workers to obtain the following information concerning natural rubber: (1) The variation of melting temperature with applied hydrostatic pressure has been calculated from the Clapeyron equation to be 0.0465° C/atm. (2) The degree of erystallinity resulting from maintaining a sample at 0° until the rate of crystallization is negligible has been calculated, by three independent methods, to be in the range 26 to 31 per cent. (3) Analysis of the stress-strain-temperature relationship has indicated that crystallization is the cause of the large internal energy changes that are observed at relatively high elongations.

On the pressure dependence of the heat of fusion and melting temperature of indium

1996 ◽  
Vol 273 ◽  
pp. 17-24 ◽  
Author(s):  
G.W.H. Höhne ◽  
W. Dollhopf ◽  
K. Blankenhorn ◽  
P.U. Mayr
Keyword(s):  
Melting Temperature ◽  
Pressure Dependence ◽  
Heat Of Fusion

Latent Heat of Fusion and Melting Temperature of Molten Salt Based Carbon Nanotube Suspensions Used as Phase Change Materials

2015 ◽  
Author(s):  
Pau Gimenez-Gavarrell ◽  
Vincent D. Romanin ◽  
Sonia Fereres
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Melting Temperature ◽  
Latent Heat ◽  
Base Fluid ◽  
Phase Change Materials ◽  
Heat Of Fusion ◽  
Latent Heat Of Fusion ◽  
Base Materials ◽  
Nanoparticle Suspensions

Thermal Energy Storage (TES) can improve the efficient and economical use of available resources associated with renewable energies. The choice of Phase Change Materials (PCM) for TES applications is particularly attractive, since PCMs provide high energy storage densities, low costs, and allow energy storage at constant temperatures during the melting/solidification process. However, most commonly used PCMs have low thermal conductivity values, typically less than 1 W/mK. This leads to insufficient heat exchange rates in many applications, where power is as important as the amount of energy stored. Previous studies have shown that adding nanoparticles to molten salts can enhance the thermal conductivity and heat capacity, thus improving performance in TES systems. This study analyzes how adding nanoparticles to ionic liquids/solids affects the latent heat of fusion and melting temperature, critical characteristics of many thermal management systems. An important aspect of nanoparticle suspension preparation is the synthesis method, both from the point of view of scalability and effect on thermophysical properties. Several nanoparticle suspensions are synthesized with carbon nanotubes (CNT) and salt or ionic liquid base materials, using different synthesis methods and sonication times. The melting point and latent heat of fusion are measured for the base materials and nanoparticle suspensions using a Differential Scanning Calorimeter (DSC). The change in latent heat and melting temperature of the nanofluid with respect to the base fluid is shown to be present but not substantial. Possible explanations for the modification of thermal properties with respect to the base fluid are discussed.

Influence Of Cr, Mn, Co and Ni on the Crystallization Behaviour of (Fel−xMx)y Metalloid1−y Metallic Glasses

1981 ◽  
Vol 8 ◽  
Author(s):  
H. W. Bergmann ◽  
U. Brokmeier
Keyword(s):  
Thermodynamic Properties ◽  
Melting Temperature ◽  
Metallic Glasses ◽  
Crystallization Behaviour ◽  
Heat Of Fusion ◽  
Temperature Crystallization

ABSTRACTThe influence of Cr, Mn, Co and Ni on the thermodynamic properties (molar heat of fusion, heat of crystallization and melting temperature), crystallization behaviour and hardness was studied in (Fe1-xMx)83B17 as a function of the x content. The crystallization behaviour can be described by three parameters which enables an extrapolation to longer times.

Melting temperature and heat of fusion of cytosine revealed from fast scanning calorimetry

2017 ◽  
Vol 657 ◽  
pp. 47-55 ◽  
Author(s):  
A. Abdelaziz ◽  
D.H. Zaitsau ◽  
T.A. Mukhametzyanov ◽  
B.N. Solomonov ◽  
P. Cebe ◽  
...  
Keyword(s):  
Melting Temperature ◽  
Heat Of Fusion ◽  
Scanning Calorimetry ◽  
Fast Scanning Calorimetry

Low Dosage Gamma Irradiation of Poly(glycerol sebacate)-co-lactic Acid Utilizing Methyl Methacrylate Crosslinker

2015 ◽  
Vol 799-800 ◽  
pp. 110-114
Author(s):  
Eduardo R. Magdaluyo ◽  
Jerilene L. Medrano
Keyword(s):  
Lactic Acid ◽  
Melting Temperature ◽  
Radiation Dosage ◽  
Energy Requirements ◽  
Heat Of Fusion ◽  
Curing Time ◽  
Thermal Curing ◽  
Time And Energy ◽  
Low Dosage ◽  
Low Radiation Dosage

The use of low dosage gamma radiation and crosslinker was explored to reduce time and energy requirements for the crosslinking of the biomedical polymer poly(glycerol sebacate)-co-lactic acid (PGS-co-LA) and to determine the effect of these parameters on the polymer’s properties. Curing time was effectively reduced to less than 2 hours from the typical 48 hours required by thermal curing. Analysis using infrared spectroscopy identifies the bonds forming PGS-co-LA and confirms the formation in all low radiation dosage settings and crosslinker amounts. Increasing the amount of crosslinker did not change the polymer’s thermal properties significantly whereas increasing the radiation dosage from 5 kGy to 10 kGy resulted to more negative value of melting temperature and increase in heat of fusion. The sample with the highest amount of crosslinker irradiated at the lowest level of radiation dosage has the least negative melting temperature and lowest heat of fusion

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