scholarly journals Supramolecular structure and thermal stability of polyamide composite fi lms containing polyfl uorinated alcohol

2019 ◽  
pp. 44-46
Author(s):  
S. V. Kudashev ◽  
V. M. Shapovalov ◽  
A. M. Valenkov ◽  
I. M. Gres ◽  
M. V. Odintsovа ◽  
...  

The infl uence of 1,1,9-trihydroperfl uorononanol-1 immobilized on montmorillonite nanoclay, supramolecular structure polycaproamide fi lms and their stability at elevated temperatures. The gaseous products of thermal degradation of polyamide fi lms, including carbon oxides, water, ε-caprolactam, aldehydes and methanol, have been studied by FTIR and mass spectroscopy. The method of thermogravimetry shows that the fl uorine-containing polyamide has a high thermal stability.

2020 ◽  
Vol 117 (8) ◽  
pp. 082405 ◽  
Author(s):  
Delin Zhang ◽  
Dingbin Huang ◽  
Ryan J. Wu ◽  
Dustin Lattery ◽  
Jinming Liu ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shengxi Wang ◽  
Anurag Roy ◽  
Kyriakos Komvopoulos

AbstractAmorphous carbon (a-C) films are widely used as protective overcoats in many technology sectors, principally due to their excellent thermophysical properties and chemical inertness. The growth and thermal stability of sub-5-nm-thick a-C films synthesized by filtered cathodic vacuum arc on pure (crystalline) and nitrogenated (amorphous) silicon substrate surfaces were investigated in this study. Samples of a-C/Si and a-C/SiNx/Si stacks were thermally annealed for various durations and subsequently characterized by high-resolution transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The TEM images confirmed the continuity and uniformity of the a-C films and the 5-nm-thick SiNx underlayer formed by silicon nitrogenation using radio-frequency sputtering. The EELS analysis of cross-sectional samples revealed the thermal stability of the a-C films and the efficacy of the SiNx underlayer to prevent carbon migration into the silicon substrate, even after prolonged heating. The obtained results provide insight into the important attributes of an underlayer in heated multilayered media for preventing elemental intermixing with the substrate, while preserving the structural stability of the a-C film at the stack surface. An important contribution of this investigation is the establishment of an experimental framework for accurately assessing the thermal stability and elemental diffusion in layered microstructures exposed to elevated temperatures.


2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  

AbstractAdvanced medium-Mn sheet steels show an opportunity for the development of cost-effective and light-weight automotive parts with improved safety and optimized environmental performance. These steels utilize the strain-induced martensitic transformation of metastable retained austenite to improve the strength–ductility balance. The improvement of mechanical performance is related to the tailored thermal and mechanical stabilities of retained austenite. The mechanical stability of retained austenite was estimated in static tensile tests over a wide temperature range from 20 °C to 200 °C. The thermal stability of retained austenite during heating at elevated temperatures was assessed by means of dilatometry. The phase composition and microstructure evolution were investigated by means of scanning electron microscopy, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy techniques. It was shown that the retained austenite stability shows a pronounced temperature dependence and is also stimulated by the manganese addition in a 3–5% range.


2013 ◽  
Vol 820 ◽  
pp. 84-87
Author(s):  
Zheng Zhou Wang ◽  
Charles A. Wilkie

Cadmin sulfate nanoparticles, hollow sphere (CdS-HS) and rode (CdS-NR) were synthesized by ultrasonic and solvothermal process, respectively. The effect of the two kinds of nanoparticles on flammability of polystyrene was investigated using cone calorimeter (Cone) and microscale combustion calorimeter (MCC). Cone data indicate that the incorporation of 1% CdS nanoparticles leads to a about 20% reduction in the peak heat release rate (PHRR) compared to the pure PS; CdS-NR is more efficient in reducing the PHRR proved by both Cone and MCC results. The TG results show that the addition of the nanoparticles mainly increases thermal stability of PS at high temepratures.


2010 ◽  
Vol 59 (4) ◽  
pp. 733-740 ◽  
Author(s):  
M. P. Yutkin ◽  
M. S. Zavakhina ◽  
D. G. Samsonenko ◽  
D. N. Dybtsev ◽  
V. P. Fedin

2017 ◽  
Vol 71 (12) ◽  
pp. 2626-2631 ◽  
Author(s):  
Jeffrey L. Wheeler ◽  
McKinley Pugh ◽  
S. Jake Atkins ◽  
Jason M. Porter

In this work, the thermal stability of the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) is investigated using infrared (IR) spectroscopy. Quantitative IR absorption spectral data are measured for heated [EMIM][EtSO4]. Spectra have been collected between 25 ℃ and 100 ℃ using a heated optical cell. Multiple samples and cell pathlengths are used to determine quantitative values for the molar absorptivity of [EMIM][EtSO4]. These results are compared to previous computational models of the ion pair. These quantitative spectra are used to measure the rate of thermal decomposition of [EMIM][EtSO4] at elevated temperatures. The spectroscopic measurements of the rate of decomposition show that thermogravimetric methods overestimate the thermal stability of [EMIM][EtSO4].


Author(s):  
F.F. do Carmo ◽  
J.P.C. do Nascimento ◽  
J.E.V. de Morais ◽  
V.C. Martins ◽  
J.C. Sales ◽  
...  

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