scholarly journals Molecular dynamic simulation of performance of modified BAMO/AMMO copolymers and their effects on mechanical properties of energetic materials

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ke Wang ◽  
Huan Li ◽  
Jun-qiang Li ◽  
Hui-xiang Xu ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Diffusion Coefficient ◽  
Glass Transition ◽  
Molecular Dynamic ◽  
Energetic Materials ◽  
Molecular Dynamic Method ◽  
Dynamic Method ◽  
Mechanical Performance ◽  
Amino Group ◽  
Glass Transition Temperatures

Abstract Based on molecular dynamic method, densities, mechanical behavior and mechanical performance of P(BAMO/ AMMO) (Polymer 1) and two novel modified P(BAMO/AMMO) (Polymer 2: containing amino group, Polymer 3: containing nitro group), and their effects on mechanical properties of four energetic materials are investigated, the main results are as follow: Polymer 2 (1.235 g/cm3, 240 ± 5 K) and Polymer 3: 1.281 g/cm3, 181 ± 3 K) possess higher densities and lower glass transition temperatures than Polymer 1 (1.229 g/cm3, 247 ± 4 K). The modification makes Polymer 1 difficult to expand, improves its mechanical properties, but has few effect on its diffusion coefficient at same temperature and state. In addition, three binders are compatible with TNT, HMX and CL-20, and may react with DNTF. All polymers particularly improve rigidity of four energetic materials, and enhance their ductility except Polymer 2 on TNT. The ability of Polymer 2 and Polymer 3 improving rigidity (except Polymer 3 on HMX) and ductility of TNT and HMX is inferior to that of Polymer 1, but it is contrary for CL-20 and DNTF (except Polymer 2 on rigidity of DNTF). Moreover, Polymer 2-based interfacial crystals exhibit higher rigidity than Polymer 3-based interfacial crystals.

The Effect of the Vulcanizing System on Cure and Mechanical Properties of Nbr/Epdm Blends

2001 ◽  
Vol 9 (7) ◽  
pp. 459-468 ◽  
Author(s):  
Marcia G. Oliveira ◽  
Bluma G. Soares
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Glass Transition ◽  
Crosslink Density ◽  
Mechanical Performance ◽  
The Other ◽  
Glass Transition Temperatures ◽  
Sulphur Concentration ◽  
Curing Characteristics ◽  
Accelerator System

The effect of the curing system and curing parameters, mechanical properties, ageing resistance, and crosslink density of NBR/EPDM blends has been investigated. The curing characteristics of the blends were affected by the accelerator type and the sulphur concentration. The sulphur/benzothiazyl-disulphide (S/MBTS) vulcanizing system offered the best scorch safety, whereas those single and binary accelerator systems based on tetramethyl thiuram disulphide (TMTD) provided faster cure. The MBTS single accelerator system was able to crosslink the EPDM phase better and consequently displayed better mechanical performance than the other systems based on tetramethyl thiuram disulphide (TMTD). Higher thermal stability was also achieved in blends containing higher levels of sulphur, probably because of increased crosslinking in the EPDM phase. The results of dynamic mechanical investigations showed differences in the glass transition temperatures, which increased with increasing of the sulphur content in both S/MBTS and S/MBTS/TMTD vulcanizing systems. Formulations based on S/TMTD single accelerator systems gave the lowest values of Tg, and the amount of sulphur did not affect this property.

The glass transition temperature measurements of polyethylene: determined by using molecular dynamic method

RSC Advances ◽  
2016 ◽  
Vol 6 (15) ◽  
pp. 12053-12060 ◽  
Author(s):  
Qing Yang ◽  
Xin Chen ◽  
Zhouwen He ◽  
Fengtao Lan ◽  
Hui Liu
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Molecular Dynamic Simulation ◽  
Molecular Dynamic ◽  
Dynamic Simulation ◽  
Molecular Dynamic Method ◽  
Dynamic Method ◽  
Temperature Measurements ◽  
Good Agreement

Different measurements of molecular dynamic simulation are used to investigated the glass transition temperature of polyethylene in this work. The simulated value of the Tg is about 200 K, which is in good agreement with available data of 195 K in the literature.

Reverse Plasticity in Nanoindentation

2007 ◽  
Vol 1049 ◽  
Author(s):  
Yongjiang Huang ◽  
Nursiani Indah Tjahyono ◽  
Jun Shen ◽  
Yu Lung Chiu
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Glass Transition ◽  
Single Crystal ◽  
Metallic Glasses ◽  
Deformation Mechanisms ◽  
Glass Transition Temperatures ◽  
Loading Rates ◽  
Nanoindentation Experiment ◽  
Properties Of Materials

AbstractThis paper summarises our recent cyclic nanoindentation experiment studies on a range of materials including single crystal and nanocrystalline copper, single crystal aluminium and bulk metallic glasses with different glass transition temperatures. The unloading and reloading processes of the nanoindentation curves have been analysed. The reverse plasticity will be discussed in the context of plastic deformation mechanisms involved. The effect of loading rates on the mechanical properties of materials upon cyclic loading will also be discussed.

Glass Transition Temperature, Mechanical Properties of Rice and their Relationships with Milling Quality

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Kobra Tajaddodi Talab ◽  
Mohd. Nordin Ibrahim ◽  
Sergey Spotar ◽  
Rosnita A. Talib ◽  
Kharidah Muhammad
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Moisture Content ◽  
Bending Strength ◽  
Bending Test ◽  
Transition Line ◽  
Transition Temperatures ◽  
Drying Process ◽  
Glass Transition Temperatures ◽  
Grain Moisture

Abstract Glass transition temperatures (Tg) of MR219 rice variety were measured by differential scanning calorimeter (DSC). State diagram was developed and used to evaluate drying process in this study. Glass transition temperatures range of 9.65- 61.79°C were observed for gains with moisture content of 26.8 – 7.4% (w.b.). For mechanical properties and milling test, statistical analysis was performed by using a two factor experiment in completely randomized design (CRD). Two selected factors were drying temperatures at 5 levels (40, 45, 50, 55, and 60°C) and final moisture content (FMC) at 4 levels (10-10.5, 11-11.5, 12-12.5 and 13-13.5%). Three–point bending test was applied to measure the mechanical properties of rice kernel. Generally, bending strength, apparent modulus of elasticity and fracture energy of brown rice kernel increased with decreasing the grain moisture content. Maximum bending strength was 35.69 and 33.64 MPa for 55, and 60°C, respectively. All samples that were dried at 55 and 60°C experienced to go through the glass transition line after reaching their temperature to the room temperature at the end of drying process. The effect of drying temperature, paddy FMC and their interactions on whole kernel percentage (WKP) and mechanical properties were significant (α = 0.05). An inverse relationship was observed between WKP and the percentage of strong kernels for all treatments.

A Molecular Dynamic Study on the Equation of State for Argon Fluid at Temperatures Near its Critical Point

2014 ◽  
Vol 543-547 ◽  
pp. 3959-3962
Author(s):  
Xiao Bin Lv ◽  
Xiao Feng Yang
Keyword(s):  
Equation Of State ◽  
Molecular Dynamic ◽  
Cluster Expansion ◽  
Simple Form ◽  
Empirical Formula ◽  
Molecular Dynamic Method ◽  
Dynamic Method ◽  
The Third ◽  
Ideal Gases ◽  
Expansion Technique

In this paper, we have developed an empirical formula describing the equation of state of argon fluid using cluster expansion technique and commonly used force parameters. To test the reliability of the formula, we have further simulated the equation of state for argon at corresponding states employing molecular dynamic method. The comparisons have shown that the empirical formula gives much better prediction than that from the simple form equation of ideal gases and the inclusion of the third virial terms in expansions is prominently important.

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