scholarly journals Polyethylene/Layered Aluminosilicate Nanocomposites: Investigation of Thermal Stability under Static and Dynamic Conditions

2017 ◽  
Vol 18 (4) ◽  
pp. 305
Author(s):  
V.V. Dolgov ◽  
Sh.G. Sadykov ◽  
M.M. Usmanova ◽  
N.R. Ashurov ◽  
S.Sh. Rashidova

Based on linear low-density polyethylene and maleated polyethylene a polymer nanocomposites containing modified montmorillonite have been obtained, structure is investigated by XRD analysis. In turn, by the methods of thermal analysis in static and dynamic modes, the resistance of polymer nanocomposites to oxidative destruction it was investigated. In parallel with this, a comparative analysis of the thermal stability of polymer nanocomposites and polymer compositions containing commercially available organic antioxidants for stabilization of materials based on polyolefins. By results of the analysis carried out in a dynamic mode, for a series of polymer composites the activation energy of thermooxidative destruction was calculated. It is shown that the nanocomposites based on polyethylene, containing the modified montmorillonite not only not concede to polymer compositions with antioxidants in to thermal stability, but also exceed their. Accelerated tests, carried out at relatively high temperatures allowed evaluate the durability of polymer nanocomposites to thermooxidative destruction. Received results allow approve about a long-term thermal stability of these materials in the processing, and in the exploitation conditions.

2021 ◽  
Vol 31 (22) ◽  
pp. 2170155
Author(s):  
Herlina Arianita Dewi ◽  
Jia Li ◽  
Hao Wang ◽  
Bhumika Chaudhary ◽  
Nripan Mathews ◽  
...  

2016 ◽  
Vol 677 ◽  
pp. 307-315 ◽  
Author(s):  
Güher Tan ◽  
Y. Eren Kalay ◽  
C. Hakan Gür

2017 ◽  
Vol 656 ◽  
pp. 70-84 ◽  
Author(s):  
D. Blanco ◽  
P. Oulego ◽  
D. Ramos ◽  
B. Fernández ◽  
J.M. Cuetos

2021 ◽  
Vol 900 (1) ◽  
pp. 012042
Author(s):  
N Stevulova ◽  
A Estokova

Abstract This paper is addressed to comparative study of changes in thermal stability of surface-modified hemp-hurds aggregates long-term incorporated in bio-aggregate-based composites with the original ones before their integration into alternative binder matrix. In this study, the effectiveness of alkaline treatment of hemp hurds compared to the raw bio-aggregates as well as in relation to their behaviour when they are long-term incorporated in the MgO-cement environment is investigated. The differences in the thermal behaviour of the samples are explained by the changed structure of hemp hurds constituents due to the pre-treatment and long-term action of the alternative binder components on the bio-aggregates. Alkaline treatment increases thermal stability of hemp hurds compared to raw sample. Also long-term incorporation of hemp hurds in MgO-cement matrix had a similar effect in case of alkaline modified bio-aggregates. The more alkali ions present in the structure of hemp hurdssamples, the more ash is formed during their thermal decomposition studied by thermal gravimetry (TG) and differential scanning calorimetry (DSC).


2021 ◽  
Vol 2144 (1) ◽  
pp. 012019
Author(s):  
S V Savushkina ◽  
A M Borisov ◽  
I V Suminov ◽  
E V Vysotina ◽  
A A Ashmarin

Abstract Nanostructured and nanocomposite layers NiCoCrAlY+ ZrO2-7%Y2O3, ZrO2-7% Y2O3+HfO2-9%Y2O3, HfO2-9%Y2O3 with thickness of ∽ 20 μm were formed by low pressure plasma spraying. The structure and composition of the layers have been studied using a scanning electron microscopy, X-ray microanalysis, and XRD analysis. Thermal stability of the coatings has been analyzed using synchronous thermal analysis at temperatures up to 1600 °C. The results of structure and composition analysis of ZrO2-7%Y2O3+HfO2-9%Y2O3 layer suggest the formation ofnanocomposite co-doped regions of the ZrO2-HfO2-Y2O3 solid solution. The layer has greater thermal stability at temperatures up to 1600 ° C and a smaller subgrain size (∽ 33 nm) than for the ZrO2-7% Y2O3 and HfO2-9%Y2O3 layers.


2019 ◽  
Vol 154 ◽  
pp. 181-192 ◽  
Author(s):  
Yuxiao Wu ◽  
Etienne Bousser ◽  
Thomas Schmitt ◽  
Nabil Tarfa ◽  
Fadila Khelfaoui ◽  
...  

2018 ◽  
Vol 28 (2) ◽  
pp. 115-133 ◽  
Author(s):  
Yuki Kubota ◽  
Takefumi Furuta ◽  
Takuya Aoki ◽  
Yuichi Ishida ◽  
Toshio Ogasawara ◽  
...  

2014 ◽  
Vol 122 ◽  
pp. 11-16 ◽  
Author(s):  
S. Behzadi ◽  
M.M. Farid

Processes ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 908 ◽  
Author(s):  
Muhammad Shahzad Kamal ◽  
Syed Muhammad Shakil Hussain ◽  
Lionel Talley Fogang

Long-term thermal stability of surfactants under harsh reservoir conditions is one of the main challenges for surfactant injection. Most of the commercially available surfactants thermally degrade or precipitate when exposed to high-temperature and high-salinity conditions. In this work, we designed and synthesized three novel betaine-based polyoxyethylene zwitterionic surfactants containing different head groups (carboxybetaine, sulfobetaine, and hydroxysulfobetaine) and bearing an unsaturated tail. The impact of the surfactant head group on the long-term thermal stability, foam stability, and surfactant–polymer interactions were examined. The thermal stability of the surfactants was assessed by monitoring the structural changes when exposed at high temperature (90 °C) for three months using 1H-NMR, 13C-NMR, and FTIR analysis. All surfactants were found thermally stable regardless of the headgroup and no structural changes were evidenced. The surfactant–polymer interactions were dominant in deionized water. However, in seawater, the surfactant addition had no effect on the rheological properties. Similarly, changing the headgroup of polyoxyethylene zwitterionic surfactants had no major effect on the foamability and foam stability. The findings of the present study reveal that the betaine-based polyoxyethylene zwitterionic surfactant can be a good choice for enhanced oil recovery application and the nature of the headgroup has no major impact on the thermal, rheological, and foaming properties of the surfactant in typical harsh reservoir conditions (high salinity, high temperature).


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