Dominant factors affecting the pressure dependence of melting temperatures in homologous series of aliphatic polyesters

2012 ◽  
Vol 48 (10) ◽  
pp. 1768-1776 ◽  
Author(s):  
David Rohindra ◽  
Keiichi Kuboyama ◽  
Toshiaki Ougizawa
Keyword(s):  
Pressure Dependence ◽  
Homologous Series ◽  
Aliphatic Polyesters ◽  
Factors Affecting ◽  
Melting Temperatures

Modeling the physical properties of a homologous series on the melting temperatures and densities of n-alkanes and their simple alkyl-derivatives

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Antun Rubčić ◽  
Jasna Rubčić ◽  
James S. Chickos
Keyword(s):  
Numerical Methods ◽  
Physical Properties ◽  
Linear Dependence ◽  
Homologous Series ◽  
Recurrence Relations ◽  
Linear Chain ◽  
Exponential Functions ◽  
Melting Temperatures ◽  
Alkyl Derivatives ◽  
Limiting Value

AbstractSeveral aspects of the melting temperatures (MT) of linear chain homologs are discussed. It is shown that with some reasonable modifications of Einstein's model of simple solids, the MT of n-alkanes and their derivatives can be successfully modeled. Results are compared with those obtained by previous authors who have used numerical methods and thermodynamics. Results of investigation of quadratic recurrence relations of the second order and forms including exponential functions are reported. Finally, the correlation of MT with density at T = 298.15 K gives the limiting value, 0.86 gcm-3 , at the temperature of nearly 420 K. It is expected that proper correlations should use densities of liquids just at the MT, because some available data suggest a linear dependence of MT on density. All results obtained are mutually consistent

Behavior of pressure dependence of melting temperatures in aromatic polyesters: Influence of polymer structure

2009 ◽  
Vol 47 (18) ◽  
pp. 1799-1808 ◽  
Author(s):  
David R. Rohindra ◽  
Masakazu Tanaka ◽  
Keiichi Kuboyama ◽  
Toshiaki Ougizawa
Keyword(s):  
Pressure Dependence ◽  
Polymer Structure ◽  
Melting Temperatures ◽  
Aromatic Polyesters

Pressure dependence of the Grüneisen parameter and melting temperature of some metals

2021 ◽  
pp. 2150255
Author(s):  
K. Sunil ◽  
D. Ashwini ◽  
Vijay S. Sharma
Keyword(s):  
Experimental Data ◽  
Molecular Dynamics ◽  
Equation Of State ◽  
Pressure Dependence ◽  
High Pressures ◽  
Grüneisen Parameter ◽  
Thermal Equation ◽  
Gruneisen Parameter ◽  
Melting Temperatures ◽  
Volume Dependence

We have used a method for determining volume dependence of the Grüneisen parameter in the Lindemann law to study the pressure dependence of melting temperatures in case of 10 metals viz. Cu, Mg, Pb, Al, In, Cd, Zn, Au, Ag and Mn. The reciprocal gamma relationship has been used to estimate the values of Grüneisen parameters at different volumes. The results for melting temperatures of metals at high pressures obtained in this study using the Lindemann law of melting are compared with the available experimental data and also with the values calculated from the instability model based on a thermal equation of state. The analytical model used in this study is much simpler than the accurate DFT calculations and molecular dynamics.

Mesomorphic Properties of Three-Benzene-Ring Containing Bent-Core Liquid Crystals 1,3-Phenylene-bis[4-(alkylcarboyloxyl)benzylideneamine]

2010 ◽  
Vol 428-429 ◽  
pp. 57-61 ◽  
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Bao Gai Zhai
Keyword(s):  
High Temperature ◽  
Liquid Crystals ◽  
Low Temperature ◽  
Benzene Ring ◽  
Homologous Series ◽  
Melting Temperatures ◽  
Temperature Ranges ◽  
Mesomorphic Properties

A homologous series of three-benzene-ring containing bent-cores compounds 1,3-phenylene-bis[4-(alkylcarboyloxyl)benzylideneamine] were synthesized. In these molecules the terminal ester chains CH3(CH2)n-2COO-, where n was the number of carbon atoms in the terminal chains, were linked to the central three-benzene-ring containing bent-core. As n changed from 1-12, the melting temperatures and clearing points were in the high temperature ranges of 136-206oC. As n changed in the range of 14-19, the melting temperatures and clearing points were dramatically dropped in a low temperature ranges 60-82oC.

Analysis of melting curves of MgO and LiF using the Lindemann law

2018 ◽  
Vol 32 (30) ◽  
pp. 1850339 ◽  
Author(s):  
K. Sunil ◽  
S. B. Sharma ◽  
B. S. Sharma
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Finite Difference ◽  
Bulk Modulus ◽  
Melting Temperature ◽  
Pressure Dependence ◽  
Grüneisen Parameter ◽  
Gruneisen Parameter ◽  
Melting Temperatures ◽  
Volume Dependence

We have determined the melting slopes as a function of pressure for MgO up to a pressure of 135 GPa, and for LiF up to a pressure of 100 GPa using the Lindemann law. Values of melting temperature have also been calculated from the melting slopes using Euler’s finite difference calculus method. It is found that the melting slope decreases continuously with the increase in pressure giving a nonlinear pressure dependence of the melting temperature. Values of bulk modulus and the Grüneisen parameter appearing in the Lindemann law of melting have been determined using the Stacey reciprocal K-primed equation of state and the Shanker reciprocal gamma relationship. The results for melting temperatures of MgO and LiF at different pressures are compared with the available experimental data. Values of melting temperatures at different pressures determined from the Al’tshuler relationship for the volume dependence of the Grüneisen parameter have also been included in the comparison presented.

Pressure dependence of melting temperatures in branched polyethylene up to 2 GPa

Polymer ◽  
1998 ◽  
Vol 39 (18) ◽  
pp. 4267-4271 ◽  
Author(s):  
S. Saeki ◽  
S. Takei ◽  
Y. Ookubo ◽  
M. Tsubokawa ◽  
T. Yamaguchi ◽  
...  
Keyword(s):  
Pressure Dependence ◽  
Branched Polyethylene ◽  
Melting Temperatures

scholarly journals Dependence of Liquid Crystalline Behaviors on Molecular Flexibility

2015 ◽  
Vol 47 ◽  
pp. 77-86 ◽  
Author(s):  
S.A. Maheta ◽  
G.N. Bhola ◽  
Umed C. Bhoya
Keyword(s):  
Liquid Crystal ◽  
Homologous Series ◽  
Liquid Crystalline ◽  
Molecular Structures ◽  
Melting Temperatures ◽  
Normal Manner ◽  
Optical Polarizing Microscopy ◽  
Transition Curves ◽  
Mesomorphic Properties ◽  
Phase Length

A novel homologous series of thermotropic liquid crystal (LC) has been synthesized with a view to understand and establish the effect of molecular structure on liquid crystal behaviors of a series. The present LC series consist of twelve homologues (C1 to C16); whose mesomorphic properties commence from octyloxy (C8) homologue of a series. C8, C10 and C12 members of a series are monotropic smectic and C14, C16 members are enantiotropically smectogenic. C1 to C7 homologues are nonmesomorphic. Nematogenic property is totally absent. Transition and melting temperatures are determined by an optical polarizing microscopy equipped with a heating stage. Textures of smectic mesophases are focal conic three or two dimensional networking of the type A or C. Cr-I/Sm and Sm-I or I-Sm transition curves behaved in normal manner. Analytical and spectral data confirms the molecular structures of homologues. Thermal stability of smectogenic mesophase is 100.6 oC and mesomorphic phase length is very short (12.9 °C to 15.3 oC). LC properties of a present novel series are compared with the structurally similar homologous series. Present series is partly smectogenic and partly non mesomorphic with poor degree of mesomorphism and middle ordered melting type without exhibition of nematogenic behavior.

scholarly journals Study of Melting Temperature of Metals: Pressure Dependence

2011 ◽  
Vol 21 (1) ◽  
pp. 77 ◽  
Author(s):  
Vu Van Hung ◽  
Hoang Van Tich ◽  
Dang Thanh Hai
Keyword(s):  
Melting Temperature ◽  
Pressure Dependence ◽  
Moment Method ◽  
Statistical Moment ◽  
Experimental Results ◽  
Melting Temperatures ◽  
Statistical Moment Method

The melting temperature of metals are studied using the statistical moment method, going the quasi-harmonic appromations. The melting temperature of metals are calculated as a function of the pressure. We discuss the pressure dependence of melting temperatures of Ce, Fe metals and compare the present results with those of the experimental results.

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