scholarly journals Factorial Design Applied for Evaluation of Effect of Interactions among Precursors on the Thermal Decomposition Temperature of Montmorillonite/Poly(Methyl Methacrylate) Nanocomposites

2017 ◽  
Author(s):  
Joseane Santana ◽  
Rennan Araujo ◽  
Filipe de Jesus ◽  
Kelly Lima ◽  
Giovanna Machado ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Methyl Methacrylate ◽  
Factorial Design ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
Poly Methyl Methacrylate

Formation of aramid-silica-grafted-multi-walled carbon nanotube-based nanofiber via the sol-gel route: thermal and mechanical profile of hybrids with poly(methyl methacrylate)

e-Polymers ◽  
2014 ◽  
Vol 14 (3) ◽  
pp. 177-185
Author(s):  
Ayesha Kausar
Keyword(s):  
Carbon Nanotube ◽  
Methyl Methacrylate ◽  
Sol Gel ◽  
Tensile Modulus ◽  
Electrospun Nanofibers ◽  
Decomposition Temperature ◽  
Filler Loading ◽  
Silica Network ◽  
Poly Methyl Methacrylate ◽  
Multi Walled Carbon Nanotube

AbstractIn this study, thermally and mechanically stable poly(methyl methacrylate) (PMMA)-based nanocomposites were produced through the reinforcement of electrospun aramid-silica-grafted multi-walled carbon nanotube-based nanofibers (MWCNT-Ar-Si). The multi-walled carbon nanotube was initially modified to prepare an isocyanatopropyltriethoxysilane-grafted MWCNT via the sol-gel route using 3-isocyanatopropyl-triethoxysilane and tetraethoxysilane (TEOS). The silica network was developed and linked to MWCNT by hydrolysis and condensation of TEOS. The said isocyanatopropyltriethoxysilane-grafted MWCNT was electrospun with the aramid solution. The electrospun MWCNT-Ar-Si nanofibers (0.1–1 wt.%) were then reinforced in a PMMA matrix. For comparative analysis, PMMA was also reinforced with 0.1–1 wt.% of aramid nanofibers. The tensile modulus of PMMA/MWCNT-Ar-Si 0.1 was 5.11 GPa, which was increased to 13.1 GPa in PMMA/MWCNT-Ar-Si 1. The 10% decomposition temperature of PMMA/MWCNT-Ar-Si 0.1–1 hybrids was in the range of 479–531°C. The glass transition temperature, determined from the maxima of tan δ data using dynamic mechanical thermal analysis, showed an increase with the filler loading and was maximum (301°C) for PMMA/MWCNT-Ar-Si 1 with 1 wt.% of MWCNT-Ar-Si nanofibers. In contrast, PMMA/Ar 0.1–1 hybrids showed lower values in the thermal and the mechanical profile depicting the combined effect of nanotube and aramid in electrospun nanofibers.

Synthesis and thermal decomposition kinetics of poly(methyl methacrylate)-b-poly(styrene) block copolymers

2015 ◽  
Vol 30 (5) ◽  
pp. 691-706 ◽  
Author(s):  
Xinghua Guan ◽  
Xiaoyan Ma ◽  
Hualong Zhou ◽  
Fang Chen ◽  
Zhiguang Li
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Weight Loss ◽  
Block Copolymers ◽  
Methyl Methacrylate ◽  
Terminal Group ◽  
Loss Ratio ◽  
Poly Methyl Methacrylate ◽  
Second Stage ◽  
Weight Loss Ratio

Two diblock copolymers of poly(methyl methacrylate)- block-poly(styrene) with chlorine as terminal group (PMMA- b-PS-Cl) were synthesized via two-step atom transfer radical polymerization. The structures of the block copolymers were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and gel permeation chromatography. Thermal properties including glass transition temperature ( Tg) and thermal stability were studied by differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. The block copolymers of PMMA- b-PS-Cl exhibited two glass transitions, which were attributed to the Tgs of PMMA and PS segments, respectively. According to TGA, thermal decompositions of PMMA macro-initiator and PMMA- b-PS-Cl block copolymers had two stages. The weight loss ratio in the second stage was more significant than that in the first stage, which may be attributed to the separation of the halogen atom from the terminal group and the formation of a double bond. The breaking down of the backbone dominates in the second stage in which the weight loss ratio was more than 70%, represented the main stage of pyrolysis. It was found that the introduction of the PS chain remarkably enhanced the thermal stability of the copolymer, thus endowing the block copolymers high activation energy for thermal decomposition. On the other hand, the remaining two pyrolysis procedures further indicated that thermodynamic mechanism didn’t change due to the introduction of PS segments.

Preparation of Magnesium Carbonate Whisker by Using Magnesite Tailings

2010 ◽  
Vol 654-656 ◽  
pp. 2022-2024
Author(s):  
Nan Wang ◽  
Yue Yuan Li ◽  
Hong Wei Ni
Keyword(s):  
Thermal Decomposition ◽  
Aspect Ratio ◽  
Magnesium Carbonate ◽  
Decomposition Temperature ◽  
Magnesium Salt ◽  
Thermal Decomposition Temperature ◽  
Stirring Intensity

Magnesium carbonate whisker was prepared by thermal decomposition of Mg(HCO3)2 solution that was prepared through hydration and carbonation of light burnt magnesia derived from magnesite tailings. The effects of thermal decomposition conditions on the morphology of magnesium carbonate crystal were investigated. Magnesium carbonate whiskers were successfully prepared when a kind of soluble magnesium salt was added, and magnesium carbonate whiskers with the length of 20 to 60μm and aspect ratio of 10~20 were obtained under the condition of 50 °C thermal decomposition temperature and 200 rpm stirring intensity.

Measurement of Thermal Decomposition Temperature and Rate of Sodium Hydride

2020 ◽  
Author(s):  
Munemichi Kawaguchi
Keyword(s):  
Thermal Decomposition ◽  
Mass Loss ◽  
Heating Temperature ◽  
Fission Products ◽  
Sodium Hydride ◽  
Decomposition Temperature ◽  
Cold Trap ◽  
Thermal Decomposition Temperature ◽  
Heating Rates ◽  
Fundamental Research

Abstract In decommissioning sodium-cooled fast reactors, the operators can be exposed to radiation during dismantling of cold trap equipment (C/T). The C/T is higher dose equipment because the C/T trapped tritium of fission products during the operation to purify the sodium coolant. In this study, thermal decomposition temperature and rate of sodium hydride (NaH) were measured as a fundamental research for development of “thermolysis” process prior to the dismantling. We measured the thermal decomposition temperature and rate using NaH powder (95.3%, Sigma-Aldrich) in alumina pan with ThermoGravimetry-Differential Thermal Analysis (TG-DTA) instrument (STA2500 Regulus, NETZSCH Japan). The heating rates of TG-DTA were set to β = 2.0, 5.0, 10.0 and 20.0 K/min. The DTA showed endothermic reaction and the TG showed two-steps mass-loss over 580K. This first-step mass-loss was consistent with change of chemical composition of the NaH with heating (NaH → Na+1/2H2). The thermal decomposition temperature and rate were obtained from the onset temperature of the mass-loss and the simplified Kissinger plots, respectively. Furthermore, we set to the thermal decomposition temperature of around 590K, and the mass-loss rates were measured. As a result, over 590K, the thermal decomposition occurred actively, and showed good agreement with the estimation curves obtained by the simplified Kissinger plots. The thermal decomposition rate strongly depended on the heating temperature.

Effect of Co(NO3)2·6H2O thermal decomposition temperature on the nano-Co3O4 product morphology and electrocatalysis of water oxidation

2019 ◽  
Vol 49 (3) ◽  
pp. 251-259 ◽  
Author(s):  
Mohammed Ameen Ahmed Qasem ◽  
Abuzar Khan ◽  
Sagheer A. Onaizi ◽  
Hatim Dafalla Mohamed ◽  
Aasif Helal ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Water Oxidation ◽  
Decomposition Temperature ◽  
Thermal Decomposition Temperature ◽  
Product Morphology

scholarly journals The influence of VO2(B) nanobelts on thermal decomposition of ammonium perchlorate

2015 ◽  
Vol 33 (3) ◽  
pp. 560-565 ◽  
Author(s):  
Yifu Zhang ◽  
Xianfang Tan ◽  
Changgong Meng
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Ammonium Perchlorate ◽  
Vanadium Dioxide ◽  
Thermo Gravimetric Analysis ◽  
Great Influence ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Thermal Decomposition Temperature ◽  
Thermo Gravimetric

Abstract The influence of vanadium dioxide VO2(B) on thermal decomposition of ammonium perchlorate (AP) has not been reported before. In this contribution, the effect of VO2(B) nanobelts on the thermal decomposition of AP was investigated by the Thermo- Gravimetric Analysis and Differential Thermal Analysis (TG/DTA). VO2(B) nanobelts were hydrothermally prepared using peroxovanadium (V) complexes, ethanol and water as starting materials. The thermal decomposition temperatures of AP in the presence of I wt.%, 3 wt.% and 6 wt.% of as-obtained VO2<B) nanobelts were reduced by 39 °C. 62 °C and 74 °C, respectively. The results indicated that VO2(B) nanobelts had a great influence on the thermal decomposition temperature of AP Furthermore, the influence of the corresponding V2Os, which was obtained by thermal treatment of VO2(B) nanobelts, on the thermal decomposition of AP was also investigated. The resufs showed that VO2(B) nanobelts had a greater influence on the thermal decomposition temperature of AP than that of V2Os.

Effect of Nano Cr2O3 in HTPB/AP/Al Based Composite Propellant Formulations

2016 ◽  
Vol 66 (2) ◽  
pp. 100 ◽  
Author(s):  
Dhirendra Kshirsagar ◽  
Ramesh Kurva ◽  
Kashinath Dhabbe ◽  
Lalita Jawale ◽  
Sudhir Singh ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Elastic Modulus ◽  
Chromium Oxide ◽  
Decomposition Temperature ◽  
Solid Loading ◽  
Thermal Decomposition Temperature ◽  
Composite Propellant ◽  
Ballistic Properties

<p>Different compositions have been prepared by incorporating nano sized chromium oxide from 0.25 % to 1 % in HTPB/AP/Al based composite propellant formulation having 86% of solid loading and studied its effect on viscosity build-up, thermal, mechanical and ballistic properties. The findings reveal that on increasing the percentage of nano Cr2O3 in the composition, there is an increase in end of mix viscosity, elastic modulus and tensile strength while elongation decreases accordingly. The data on thermal properties envisage the reduction in thermal decomposition temperature of ammonium perchlorate as well as formulations based on HTPB/AP/Al. The data on ballistic properties reveal that there is an enhancement in burning rate from 6.11 mm/s to 7.88 mm/s at 6.86 MPa, however, marginal increase in  pressure exponent (‘n’ values) from 0.35 to 0.53 with 1 wt % of nano Cr2O3 was observed  in comparison to reference composition without chromium oxide. </p><p> </p>

Studies on Thermal Stability and Rheological Property of PU/PVDF Blend

2011 ◽  
Vol 311-313 ◽  
pp. 1065-1070
Author(s):  
Guo Lan Huan ◽  
Jian Li Liu ◽  
Qi Yun Du ◽  
Xiao Yu Hu
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Decomposition ◽  
Shear Stress ◽  
Rheological Property ◽  
Decomposition Temperature ◽  
Dynamic Equations ◽  
Thermal Decomposition Temperature ◽  
Thermal Stability Of ◽  
Decomposition Activation Energy

In this article, the thermal stability of PU/PVDF blend was investigated by thermogravimetry (TG), and their rheological property was studied through testing and analyzing the rheological curves. The results showed that, with the increase in PVDF content, the thermal decomposition temperature of PU/PVDF blend increased, and by fitting relevant data to thermal decomposition dynamic equations, it was found that thermal decomposition activation energy of the blend increased gradually, i.e. the thermal stability of the blend increased gradually. Meantime, based on the curves of shear stress vs. shear rate of the blend at 180°C and 200°C, it was shown that for PU/PVDF blend, with the decrease of temperature and the increase in PVDF content, the non-Newtonian index decreased, while the viscosity of the blend increased.

A Further Research on the Properties of PLA/TiO2 Nanocomposites

2014 ◽  
Vol 608-609 ◽  
pp. 996-1000
Author(s):  
Yan Bing Luo
Keyword(s):  
Mechanical Property ◽  
Thermal Decomposition ◽  
Lactic Acid ◽  
Thermal Property ◽  
Deformation Temperature ◽  
Thermal Deformation ◽  
Decomposition Temperature ◽  
Dynamic Mechanical Property ◽  
Thermal Decomposition Temperature ◽  
Inorganic Nanocomposites

Organic/inorganic nanocomposites have been widely focused because of their special properties. By modifying nanoTiO2and polylactic acid (PLA) with lactic acid, PLA/TiO2nanocomposites was prepared, and the test on the dynamic mechanical property, thermal property, and thermal deformation temperature showed that adding nanoTiO2helped improve PLA's mechanics property, thermal decomposition temperature, and thermal deformation temperature to certain extent.

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