Determination of Activation Energy of Relaxation events in composite solid propellants by Dynamic Mechanical Analysis

2014 ◽  
Vol 64 (2) ◽  
pp. 173-178 ◽  
Author(s):  
Bipin Bihari ◽  
V. Wani ◽  
N. Rao ◽  
P. Singh ◽  
B. Bhattacharya
Keyword(s):  
Activation Energy ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Solid Propellants ◽  
Dynamic Mechanical ◽  
Composite Solid Propellants ◽  
Composite Solid

scholarly journals Temperature Variability of Poisson’s Ratio and Its Influence on the Complex Modulus Determined by Dynamic Mechanical Analysis

Technologies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 81
Author(s):  
Vitor Carneiro ◽  
Helder Puga
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Poisson’S Ratio ◽  
Complex Modulus ◽  
Mechanical Analysis ◽  
Temperature Variability ◽  
Poisson's Ratio ◽  
Constant Frequency ◽  
Dynamic Mechanical ◽  
Characterization Of Materials

Dynamic mechanical analysis (DMA) is the usual technology for the thermomechanical viscoelastic characterization of materials. This method monitors the instant values of load and displacement to determine the instant specimen stiffness. Posteriorly, it recurs to those values, the geometric dimensions of the specimen, and Poisson’s ratio to determine the complex modulus. However, during this analysis, it is assumed that Poisson’s ratio is constant, which is not always true, especially in situations where the temperature can change and promote internal modification in the specimens. This study explores the error that is imposed in the results by the determination of the real values of complex moduli due to variable Poisson’s ratios arising from temperature variability using a constant frequency. The results suggest that the evolution of the dynamic mechanical analysis should consider the Poisson’s ratio input as a variable to eliminate this error in future material characterization.

Dynamic Mechanical Analysis of Polyurethane-Epoxy Interpenetrating Polymer Networks

2009 ◽  
Vol 21 (5) ◽  
pp. 608-623 ◽  
Author(s):  
Mariana Cristea ◽  
Sorin Ibanescu ◽  
Constantin N. Cascaval ◽  
Dan Rosu
Keyword(s):  
Activation Energy ◽  
Molecular Dynamics ◽  
Dynamic Mechanical Analysis ◽  
Loss Factor ◽  
Loss Modulus ◽  
Polymer Networks ◽  
Mechanical Analysis ◽  
Interpenetrating Polymer Networks ◽  
Dynamic Mechanical ◽  
Tan Δ

A series of semi-interpenetrated polymer networks based on bisphenol A epoxy resin and polyurethane was synthesized by sequential procedure. The molecular dynamics of polyurethane incorporated in the resin network with increasing amounts of resin was followed by dynamic mechanical analysis. All phenomena that concur in the material are evaluated by cross-examination of the storage modulus ( E'), loss modulus ( E'') and loss factor (tan δ) variation with temperature. Complex aspects were elucidated in consecutive heating-cooling-heating cycles and by calculating the apparent activation energy of relaxations in multiplex experiments.

Determination of Primary Amine Content in Bonding Agent Used in Composite Solid Propellants

2014 ◽  
Vol 39 (4) ◽  
pp. 538-544 ◽  
Author(s):  
José I. S. Oliveira ◽  
Darci C. Pires ◽  
Milton F. Diniz ◽  
Jorge L. Siqueira ◽  
Elizabeth C. Mattos ◽  
...  
Keyword(s):  
Primary Amine ◽  
Bonding Agent ◽  
Solid Propellants ◽  
Amine Content ◽  
Composite Solid Propellants ◽  
Composite Solid

Elastic Modulus Determination of ß-Si6-xAlxOxN8-x with Rare Earth Concentrate by Dynamic Mechanical Analysis

2003 ◽  
Vol 416-418 ◽  
pp. 579-583 ◽  
Author(s):  
I.R. Ruiz ◽  
Hidetoshi Takiishi ◽  
Rubens Nunes de Faria Jr. ◽  
Luis Filipe C.P. de Lima ◽  
José Carlos Bressiani
Keyword(s):  
Rare Earth ◽  
Elastic Modulus ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Dynamic Mechanical
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