Some Aspects of Time-Temperature Superposition Principle Applied for Predicting Mechanical Properties of Solid Rocket Propellants

1999 ◽  
Vol 24 (4) ◽  
pp. 221-223 ◽  
Author(s):  
Radun Jeremic
Keyword(s):  
Mechanical Properties ◽  
Superposition Principle ◽  
Rocket Propellants ◽  
Temperature Superposition ◽  
Time Temperature Superposition ◽  
Solid Rocket ◽  
Time Temperature Superposition Principle ◽  
Solid Rocket Propellants

Integration of Atomistic Simulation with Experiment Using Time−Temperature Superposition for a Cross-Linked Epoxy Network

2019 ◽  
Author(s):  
Ketan Khare ◽  
Frederick R. Phelan Jr.
Keyword(s):  
Master Curve ◽  
Glassy State ◽  
Superposition Principle ◽  
Quantitative Comparison ◽  
Time Shift ◽  
Data Sets ◽  
Epoxy Network ◽  
Temperature Superposition ◽  
Time Temperature Superposition ◽  
Time Temperature Superposition Principle

<a></a><a>Quantitative comparison of atomistic simulations with experiment for glass-forming materials is made difficult by the vast mismatch between computationally and experimentally accessible timescales. Recently, we presented results for an epoxy network showing that the computation of specific volume vs. temperature as a function of cooling rate in conjunction with the time–temperature superposition principle (TTSP) enables direct quantitative comparison of simulation with experiment. Here, we follow-up and present results for the translational dynamics of the same material over a temperature range from the rubbery to the glassy state. Using TTSP, we obtain results for translational dynamics out to 10<sup>9</sup> s in TTSP reduced time – a macroscopic timescale. Further, we show that the mean squared displacement (MSD) trends of the network atoms can be collapsed onto a master curve at a reference temperature. The computational master curve is compared with the experimental master curve of the creep compliance for the same network using literature data. We find that the temporal features of the two data sets can be quantitatively compared providing an integrated view relating molecular level dynamics to the macroscopic thermophysical measurement. The time-shift factors needed for the superposition also show excellent agreement with experiment further establishing the veracity of the approach</a>.

scholarly journals Synthesis of HTPB using a semi-batch method

2020 ◽  
pp. 192-202
Author(s):  
Michał Chmielarek ◽  
Wincenty Skupiński ◽  
Zdzisław Wieczorek
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Peroxide ◽  
Synthesis Method ◽  
Batch Method ◽  
Synthesis Conditions ◽  
Rocket Propellants ◽  
Wide Range ◽  
Military Applications ◽  
Solid Rocket ◽  
Solid Rocket Propellants

Hydroxyl-terminated polybutadiene is widely used in industry for both civil and military applications. In munitions, HTPB is mostly used as a binder for heterogenic rocket propellants and as a component of plastic bonded explosives, as well as a phlegmatizer in explosives sensitive to friction and impact. The wide range of HTPB applications results from the good mechanical properties of HTPB-based polyurethanes, in particular at temperatures down to –40 °C. A synthesis method for HTPB, different from the commonly used semi-batch and continuous methods, is presented. The effect of parameters including reaction temperature, 1,3-butadiene pressure and hydrogen peroxide concentration on the properties of the obtained polymer is determined. The synthesis conditions enabling new HTPB species to be obtained, which meet the requirements for binders used in solid rocket propellants, are specified.

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