scholarly journals RESEARCH OF THERMAL PROPERTIES OF UHMWPE BASED COMPOSITES AFTER EXPLOSIVE PRESSING

2021 ◽  
pp. 34-37
Author(s):  
N. A. Adamenko ◽  
G. V. Agafonova ◽  
V. S. Pirozhenko ◽  
D. A. An ◽  
D. V. Savin ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermal Oxidation ◽  
Crystalline Phase ◽  
Thermal Destruction ◽  
Chemical Interaction ◽  
Thermal Characteristics ◽  
Melting Points ◽  
Similar Composition ◽  
Cross Links ◽  
Explosive Pressing

The thermal characteristics of the initial UHMWPE and its composites with QGP and MDF, as well as those obtained by explosive pressing (VP), have been investigated. It has been established that explosive pressing leads to hindering the processes of melting and thermal destruction, which may be associated with chemical interaction, the formation of inter- and intramolecular cross-links characteristic of this polymer. UHMWPE and its compositions with 3% CHP after VP have higher melting points of the crystalline phase, thermal oxidation and thermal destruction in comparison with the starting materials of similar composition. In the UHMWPE composition with 10% MDF, no increase in thermal properties after VP was observed, similar to the original fluoroplastic.

scholarly journals RESEARCH OF THERMAL PROPERTIES OF UHMWPE BASED COMPOSITES AFTER EXPLOSIVE PRESSING

2021 ◽  
pp. 34-37
Author(s):  
N. A. Adamenko ◽  
G. V. Agafonova ◽  
V. S. Pirozhenko ◽  
D. A. An ◽  
D. V. Savin ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Thermal Oxidation ◽  
Crystalline Phase ◽  
Thermal Destruction ◽  
Chemical Interaction ◽  
Thermal Characteristics ◽  
Melting Points ◽  
Similar Composition ◽  
Cross Links ◽  
Explosive Pressing

The thermal characteristics of the initial UHMWPE and its composites with QGP and MDF, as well as those obtained by explosive pressing (VP), have been investigated. It has been established that explosive pressing leads to hindering the processes of melting and thermal destruction, which may be associated with chemical interaction, the formation of inter- and intramolecular cross-links characteristic of this polymer. UHMWPE and its compositions with 3% CHP after VP have higher melting points of the crystalline phase, thermal oxidation and thermal destruction in comparison with the starting materials of similar composition. In the UHMWPE composition with 10% MDF, no increase in thermal properties after VP was observed, similar to the original fluoroplastic.

Alternating poly(ester amide)s from glutaric anhydride and α,ω-aminoalcohols: synthesis and thermal properties

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Thomas Fey ◽  
Helmut Keul ◽  
Hartwig Höcker
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Homologous Series ◽  
Average Molecular Weight ◽  
Number Average Molecular Weight ◽  
Melting Points ◽  
Glutaric Anhydride ◽  
H Nmr ◽  
Activating Agent ◽  
Dimethylformamide Solution

Abstract Alternating poly(ester amide)s 6a - e were prepared by polycondensation of α-carboxyl-ω-hydroxyamides 3a - e which were obtained by aminolysis of glutaric anhydride (1) and α,ω-aminoalcohols, H2N-(CH2)x-OH (x = 2 - 6) 2a - e. The polycondensation was performed in dimethylformamide solution using a carbodiimide as activating agent, or in bulk with Bu2Sn(OMe)2, Ti(OBu)4 and Sn(octoate)2 as a catalyst. For the polycondensation in bulk, the influence of catalyst and of temperature on the number-average molecular weight was studied. 1H NMR analyses of the poly(ester amide)s clearly show the alternating microstructure. The poly(ester amide)s from glutaric anhydride and the homologous series of α,ω-aminoalcohols are semicrystalline materials; their melting points show the odd/even effect observed for other poly(ester amide)s.

Investigation of the Structure and Distribution of Chemical Elements between the Phases of Hard Alloys of the Cr3C2-Ti System, Obtained at Various Modes of Explosive Compaction

2020 ◽  
Vol 992 ◽  
pp. 487-492
Author(s):  
V.O. Kharlamov ◽  
Aleksandr Vasilevich Krokhalev ◽  
S.V. Kuz’min ◽  
V.I. Lysak
Keyword(s):  
Phase Composition ◽  
Powder Mixture ◽  
Chemical Interaction ◽  
Chemical Elements ◽  
Equilibrium Phase ◽  
Hard Alloys ◽  
Explosive Compaction ◽  
Thermo Calc Software ◽  
Equilibrium Phases ◽  
Explosive Pressing

The Article presents the findings of the studies of the microstructure, chemical and phase composition of the Cr3C2-Ti system alloys obtained by the explosion. Scanning electron microscopy, energy dispersive and x-ray diffraction analyses were used. The program Thermo-Calc software was used to calculate the equilibrium phases. The phase composition of the compact was shown to fully correspond to that of the initial powder mixture during explosive pressing in the modes of heating from 300 ̊С to 600 ̊С. When heated above 600 ̊С, the chemical interaction of the initial components begins with the formation of new boundary phases. Meanwhile, there is a change in the sample destruction nature and a significant increase in hardness, which points to the hard alloy consolidation. The increase in the powder mixture heating in shock waves to 1000 ̊С leads to intensive macrochemical interaction of the powder mixture components and to formation of an equilibrium phase composition. The established temperature limits determine the most appropriate parameters of shock-wave loading when producing hard alloys by explosive pressing.

scholarly journals Effect of the annealing procedure and the molecular weight on the crystalline phase morphology and thermal properties of polylactide

2019 ◽  
Vol 68 (10) ◽  
pp. 1767-1775 ◽  
Author(s):  
Martí Hortós ◽  
Jon Anakabe ◽  
Alex Arrillaga ◽  
Sebastián Espino ◽  
Jordi J Bou
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Crystalline Phase ◽  
Phase Morphology ◽  
Annealing Procedure

scholarly journals A Study of the Mechanical and Thermal Characteristics of an Al-Si-Fe Alloy Fabricated by Rolling and Heat Treatment

Metals ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Yu Guo ◽  
Ye Wang ◽  
Jieren Yang ◽  
Hongyu Xu ◽  
Maoliang Hu ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Properties ◽  
Cast Alloy ◽  
Thermal Characteristics ◽  
Spherical Shape ◽  
Mean Free Path ◽  
Homogeneous Distribution ◽  
Mechanical And Thermal Properties ◽  
Obvious Effect ◽  
T6 Heat Treatment

The effects of a rolling process and heat treatment on the mechanical and thermal properties of an Al-Si-Fe alloy were studied. The achieved thermal conductivity of the as-rolled alloy treated by a T6 heat treatment was 188.22 W/(m·K), which is as good as that of the as-cast alloy treated by the T6 heat treatment directly, mostly because of changes in the silicon morphology. The results also revealed that the lower quantity of precipitated Al8Fe2Si and Mg2Si phases had no obvious effect on the thermal properties of the material because the interphase spaces between precipitated phases were larger than the mean free path of electrons. However, the precipitated second phases influenced the elongation. The best mechanical properties of the Al-Si-Fe alloy were obtained by rolling and T6 treatment. The corresponding best tensile strength, yield strength, and elongation were 244 MPa, 295 MPa, and 9.56%, respectively, which are attributed to the near-spherical shape, small size, homogeneous distribution of the Si particles, and the precipitation strengthening of Mg2Si.

Effect of Ventilation in Protected Escape Ways upon the Thermal Properties of these Spaces

2016 ◽  
Vol 861 ◽  
pp. 409-416
Author(s):  
Marie Rusinová ◽  
Markéta Sedláková ◽  
Miloš Kalousek
Keyword(s):  
Thermal Properties ◽  
Positive Pressure Ventilation ◽  
Thermal Characteristics ◽  
Positive Pressure ◽  
Escape Route

Protected escape routes enable the rescuing of persons to the outside of a building on fire. They are characterized, in particular, by strict requirements relating to the aeration of such spaces. However, the fulfilling of these limits may impact the monitored thermal characteristics of the respective internal areas. The outlined dilemma will be illustrated by way of an example of a protected escape route aerated by positive-pressure ventilation.

Pore Structure and Thermal Characteristics of Clay Bricks

2014 ◽  
Vol 982 ◽  
pp. 104-107 ◽  
Author(s):  
Monika Čáchová ◽  
Dana Koňáková ◽  
Eva Vejmelková ◽  
Martin Keppert ◽  
Kirill Polozhiy ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Structural Material ◽  
Physical Properties ◽  
Thermal Characteristics ◽  
Clay Brick ◽  
Pore System ◽  
Clay Bricks ◽  
Vacuum Saturation ◽  
The Difference ◽  
System Characteristics

Clay brick was perhaps to be the first artificial structural material. First bricks were dried by sun; later people had started to burn bricks by fire and in that time further enhancements appeared. This article deals with two kinds of fired clay bricks; basic physical properties, pore system characteristics and thermal properties are studied. The values of basic physical properties by water vacuum saturation vary slightly; bulk density shows values around 1880 kg/m3 and in the case of open porosity it is around 27%. Regarding thermal properties the difference is higher, obtained results of thermal conductivities in dried state vary by about 33%.

Influence of Moisture Content on the Thermal Properties of Concrete Containing Agricultural Waste Materials

2016 ◽  
Vol 677 ◽  
pp. 241-245
Author(s):  
Dana Koňáková ◽  
Monika Čáchová ◽  
Eva Vejmelková
Keyword(s):  
Thermal Properties ◽  
Moisture Content ◽  
Physical Properties ◽  
Agricultural Waste ◽  
Thermal Characteristics ◽  
Waste Materials ◽  
Experimental Measurements ◽  
Transport Parameters ◽  
Cement Replacement ◽  
Coir Pith

This article deals with concrete containing waste material originating in a coir fibres extraction from outer protective peel of a coconut. Coir pith is used as cement replacement in amount of 5% and 10%. The influence of moisture content on the thermal properties of studied concrete is determined by means of experimental measurements of basic physical properties, hygric transport parameters and thermal characteristics. From achieved results it can be concluded, that the higher amount of coir pith is used, the better values of thermal characteristics material show. But at the same time thermal characteristics are more influenced by moisture content.

scholarly journals EFFECT OF ALUMINUM DROSS AND RICE HUSK ASH ON THERMAL AND MOULDING PROPERTIES OF SILICA SAND

2017 ◽  
Vol 36 (3) ◽  
pp. 794-800
Author(s):  
EF Ochulor ◽  
HOH Amuda ◽  
SO Adeosun ◽  
SA Balogun
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Thermal Characteristics ◽  
Silica Sand ◽  
Cast Part ◽  
Solidification Kinetics ◽  
Moulding Sand

Moulding properties of foundry sand should be controlled so as to minimize casting defects. Its thermal characteristics are vital in defining the solidification kinetics of a cast part,  evolving microstructure and mechanical properties. Modification of the thermal properties of the moulding sand mix is important in achieving desired structure and mechanical properties in the cast component. This study investigates the incorporation of 2-12 wt. % aluminium dross (AlDr) and 1-6 wt. % rice husk ash (RHA) in silica sand on moulding and thermal properties of the resulting sand mix. Results show that RHA significantly reduced thermal conductivity of the moulding sand from 1.631-1.141 W/m. K (a 30% reduction).However, AlDr increased its thermal conductivity from 1.631-1.787 W/m.K for 1-6 wt. % AlDr, which later dropped progressively from 1.753-1.540 W/m.K for 8-12 wt. %. The moisture content increased abruptly from 4.0-4.2 % for 6-8 wt. % AlDr addition but decreased from 4.0-2.8% for0-6 wt. % RHA addition in the moulding sand mix. http://dx.doi.org/10.4314/njt.v36i3.19

scholarly journals Physicochemical and thermal properties of durian seed flour from three varieties of durian native of Sabah

Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 374-381
Author(s):  
Siti Faridah M.A. ◽  
Nur Atikah M.R.L. ◽  
Jau-Shya L. ◽  
Hasmadi M. ◽  
Mohd Rosni S. ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Protein Content ◽  
High Capacity ◽  
Thermal Characteristics ◽  
Absorption Capacity ◽  
Assessment Process ◽  
Composite Flour ◽  
Seed Flour ◽  
Seed Flours ◽  
Durian Seed

This study was aimed at assessing the physicochemical and thermal properties of flour, acquired from the seeds of three native Sabah durian species. The three durian species concerned are the Dalit, Sukang and Pulu. Flour deriving from the seeds of the dalit (DDSF), sukang (DSSF) and pulu (DPSF) durian species, were put through a physicochemical, pasting and thermal characteristics assessment process. The protein content in flours, derived from the seeds of durian native to Sabah, demonstrated a high capacity for the absorption of both water (r = -0.855, p<0.01), and oil (r = 0.921, p<0.01). DPSF, which holds the most protein content at 6.92%, demonstrated the lowest water absorption capacity, and greatest oil absorption capacity (p<0.05). Moreover, DPSF was observed to have the lowest swelling power, solubility and peak viscosity (p<0.05). In terms of pasting temperature, no outstanding disparities were detected between the three durian seed flours (p>0.05), but they were considered to have high pasting temperatures. The lowest setback viscosity (p<0.05) displayed by DPSF, is an indication that the following gelatinization, will quickly dissolve. Additionally, the enthalpy ΔH of DPSF revealed as 0.29 J/g (p<0.05) is deemed significantly low. This undertaking delves into the physicochemical and thermal characteristics of durian seed flour, to its use as composite flour.

Sign in / Sign up

Export Citation Format

Share Document