scholarly journals Thermally Stable Forms of Pure Polyaniline Catalyzed by an Acid-Exchanged Montmorillonite Clay Called Maghnite- as an Effective Catalyst

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Rahmouni Abdelkader ◽  
Harrane Amine ◽  
Belbachir Mohammed
Keyword(s):  
Oxidative Polymerization ◽  
Montmorillonite Clay ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Effective Catalyst ◽  
H Nmr ◽  
Western Algeria ◽  
Local Company ◽  
Stable Forms ◽  
Thermal Stability Of

Polyaniline salt form (PANI-ES) was synthesized by oxidative polymerization of aniline using potassium persulfate as an oxidant and an acid-exchanged montmorillonite clay called Maghnite-H+as an effective catalyst. The clay, which was used as a catalyst, was supplied by a local company known as ENOF Maghnia (Western Algeria). The chemical stability of PANI has been investigated by thermogravimetry and differential scanning calorimetry, that a good thermal stability of PANI could be improved by combining PANI with montmorillonite. TGA results illustrated that there were two major stages for weight loss of the ES-form PANI powder sample. The different forms of PANI were characterized by infrared spectroscopy, thermal analysis, and H-NMR spectroscopy and conductivity measurements.

scholarly journals Synthesis of Polyethers Containing Triazole Units in the Backbone by Click Chemistry in a Tricomponent Reaction

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Moslem Mansour Lakouraj ◽  
Vahid Hasantabar ◽  
Nazanin Bagheri
Keyword(s):  
Thermal Stability ◽  
Click Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
One Pot ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Good Solubility ◽  
Nmr Techniques ◽  
Thermal Stability Of

A series of linear aromatic polyethers containing triazole units were synthesized via the direct click reaction of dibromide and bisethynyl compounds in the presence of sodium azide as one pot reaction. The structures of polymers were approved by using IR and 1H NMR techniques. The solubility experiments showed that polymers have good solubility in polar aprotic solvents such as DMSO, DMF, and NMP at higher temperatures. Thermal stability of the polymers was measured using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) which indicated that they possessed good thermal stability ( up to 558°C) and high (191.7–260°C) under N2 atmosphere. All the polymers were amorphous according to the DSC and X-ray diffraction. These polymers exhibited strong UV-vis absorption maxima near to 400 nm and up to 500 nm in DMSO solution.

Synthesis and Application of a Novel Intumescent Flame Retardant Containing Ferrocenyl

2014 ◽  
Vol 1033-1034 ◽  
pp. 931-936
Author(s):  
Cong Yan Chen ◽  
Rui Lan Fan ◽  
Guan Qun Yun
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Flame Retardants ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
H Nmr ◽  
Positive Effect ◽  
Thermal Stability Of ◽  
Phosphate Groups

A novel intumescent flame retardant (IFR) containing ferrocene and caged bicyclic phosphate groups, 1-oxo-4-[4'-(ferrocene carboxylic acid phenyl ester)] amide-2, 6, 7-trioxa-1-phosphabicyclo- [2.2.2] octane (PFAM), was successfully synthesized. The synthesized PFAM were added to flammable polyurethane (PU) as flame retardants and smoke suppressants. The structure of PFAM was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR) and elemental analysis. Thermal stability of PFAM was tested by themogravimetric analysis (TGA). The results revealed that PFAM had good thermal stability and high char weight, the char weight up to 54% at 600 °C. Flammability properties of PU/PFAM composites were investigated by limiting oxygen index (LOI) test and UL-94 test, respectively. The results of LOI tests showed that the addition of PFAM enhanced flame retardancy of PU. When the content of PFAM reaches to 3%, the LOI value is 22.2. The morphologies of the char for PU and PU/3% PFAM composite can be obtained after LOI testing were examined by SEM. The results demonstrated that PFAM could promote to form the compact and dense intumescent char layer. Experiments showed that, the PFAM application of polyurethane showed positive effect.

scholarly journals Electrospun Silk-Boron Nitride Nanofibers with Tunable Structure and Properties

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1093
Author(s):  
Ye Xue ◽  
Xiao Hu
Keyword(s):  
Thermal Stability ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Environmental Research ◽  
Strong Interactions ◽  
Helical Structures ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Thermal Stability Of

In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and the strong interactions between BN and SF molecules were revealed by temperature modulated differential scanning calorimetry (TMDSC). With the addition of BN, the boundary water content also decreased, which may be due to the high hydrophobicity of BN. These results indicate that silk-based BN composite nanofibers can be potentially used in biomedical fields or green environmental research.

Synthesis and Thermal Stability of Unsaturated Polyamides

1992 ◽  
Vol 4 (2) ◽  
pp. 67-71
Author(s):  
N. R. Patel ◽  
N. Z. Patel ◽  
R. M. Patel
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Scanning Calorimetry ◽  
Aromatic Diamines ◽  
Good Thermal Stability ◽  
Kinetics Of Decomposition ◽  
Glutaconic Acid ◽  
Kinetics Of ◽  
Thermal Stability Of

Unsaturated polyamides were prepared by condensing /3(4-ethoxyphenyl) glutaconic acid with various aromatic diamines. The polycondensates were characterized by IR spectroscopy, vapor phase osmometry, thermogravimetric analysis, differential scanning calorimetry and elemental analysis. All resins were found to decompose in the range '-210-600 °C. The kinetics of decomposition were studied. The results indicated that the resins possess reasonably good thermal stability.

scholarly journals Thermal Stability Analysis of the Mg/TeO2 Ignition Composition after 180 °C Exposure

2020 ◽  
Vol 10 (22) ◽  
pp. 8122
Author(s):  
Xiang He ◽  
Yaokun Ye ◽  
Nan Yan ◽  
Feng Ding ◽  
Chaozhen Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Environment ◽  
Exothermic Reaction ◽  
Pressure Rise ◽  
Optical Microscope ◽  
Main Reaction ◽  
Scanning Calorimetry ◽  
Change Analysis ◽  
Good Thermal Stability ◽  
Thermal Stability Of

In order to satisfy the performance requirements of the pyrotechnic ignition composition of a space mission under an extreme thermal environment, it is necessary to analyze and verify the thermal stability of magnesium/tellurium dioxide (Mg/TeO2) ignition composition at a temperature of 180 °C. The thermal stability of the ignition composition of Mg/TeO2 and its components after exposure to 180 °C for 2–10 days was studied by means of apparent morphology analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), content change analysis, and the P-t curve test. The results showed that after exposure to 180 °C for 2–10 days, no obvious changes, such as ruptures, expansion, or shrinkage, were found by optical microscope, and no changes in morphology and surface details were found by scanning electron microscope (SEM). XRD showed that no other new substance was found in the mixture except magnesium hydroxide (Mg (OH)2). DSC showed that the main reaction peak temperature of the ignition composition of Mg/TeO2 was after 500 °C and that no endothermic/exothermic reaction occurred before 380 °C. The exothermic pre-reaction took place at 381 °C to 470 °C, the weight loss ratio was within 0.71%, the content of the magnesium component varied from 0.49% to 0.90%, the peak pressure attenuation of the ignition composition of 360-mesh Mg/TeO2 was 8.07%, and the pressure rise time was basically unchanged. The results showed that the ignition composition of Mg/TeO2 had good thermal stability after exposure to 180 °C temperatures.

Halogenated sunflower oil as a precursor for synthesis of polysulfide polymer

e-Polymers ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Samira Moqadam ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Sunflower Oil ◽  
Proton Nuclear Magnetic Resonance ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir ◽  
Harsh Conditions ◽  
Thermal Stability Of ◽  
Polysulfide Polymer

AbstractPolysulfide polymers usually are prepared by the reaction of different dihalide compounds with disodium polysulfides. In this field, dihalides are expensive and produced from halogenation of organic compounds by different methods with harsh conditions. To overcome this problem, in this work, sunflower oil as polyunsaturated oil was used as precursor to produce polyhalide compound. In this field, double bonds of oil were applied as functional groups to halogenate the sunflower via benzoyl peroxide-catalyzed reaction with hydrochloric acid. Also, Na2S3 was synthesized via the reaction between sulfur and sodium hydroxide. Then, halogenated oil was reacted with Na2S3 to produce sunflower oil-based polysulfide polymer. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) were used to characterize the structure of sunflower oil and synthesized polysulfide polymer. The content of halogenation was also obtained via energy-dispersive X-ray spectroscopy (EDX). Thermal stability of synthesized polymer was determined by means of thermal gravimetric analysis (TGA) and glass transition temperature was investigated by differential scanning calorimetry (DSC).

Optically active polymer: synthesis and characterization of new optically active poly (hydrazide-imide)s incorporating L- leucine

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Specific Rotation ◽  
Optically Active ◽  
Gravimetric Analysis ◽  
Optically Active Polymer ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Good Thermal Stability ◽  
H Nmr

AbstractThis paper deals with the polycondensation between a chiral diacyl chloride (N,N′-Pyromelliticdiimido-di-L-leucine chloride) and six different dihydrazides. The corresponding poly (hydrazide-imide)s which have been obtained in quantitative yields are moderately soluble in polar aprotic solvents, have good thermal stability and optical activity. The synthetic compounds have been characterized by IR, UV and 1H NMR spectroscopy, elemental analysis and specific rotation. The thermal properties of the polymers (10 and 15) have been studied by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC).

Preparation of Nickel/Poly(m-Toluidine) Composites and its Magnetic Properties

2012 ◽  
Vol 217-219 ◽  
pp. 142-145
Author(s):  
Hong Wang ◽  
Yong Zhong Jin ◽  
Tao Wang ◽  
Di Liu ◽  
Xue Fei Li
Keyword(s):  
Quantum Interference ◽  
Oxidative Polymerization ◽  
Ammonium Persulfate ◽  
Ferromagnetic Behavior ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Ni Powder ◽  
Thermal Stability Of

Ni/poly(m-toluidine)(PMT) nanocomposites were prepared by in situ chemical oxidative polymerization of m-toluidine (MT) monomer in the presence of Ni powder, with ammonium persulfate (APS) as oxidant and citric acid (C6H8O7) as dopant. The resultant products were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and superconducting quantum interference device magnetometer (SQUID). The results exhibited that Ni/PMT nanocomposites show a ferromagnetic behavior with saturation magnetization strength (Ms) and coercivity of 28.4emu/g and 105.8Oe at room temperature. The prepared Ni/PMT composites were soft and ferromagnetic materials. Moreover, thermal Stability of nanocomposites was also investigated.

Glass Fiber Reinforced Composites of Coloured Epoxy Resin Cured with Different Amines

2002 ◽  
Vol 10 (6) ◽  
pp. 441-446
Author(s):  
Milan R. Patel ◽  
Manish P. Patel ◽  
Rashmika H. Patel ◽  
Ranjan G. Patel
Keyword(s):  
Thermal Stability ◽  
Epoxy Resin ◽  
Chemical Resistance ◽  
The Novel ◽  
Reinforced Composites ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Glass Fiber Reinforced ◽  
Fibre Composites ◽  
Thermal Stability Of

A novel coloured epoxy resin has been synthesized by reaction between epichlorohydrin and bisazodiol. The curing of the resin, blended with a DGEBA resin, were characterized by differential scanning calorimetry (DSC). The thermal stability of the cured products has been investigated by thermogravimetric analysis (TGA). The cured products showed good thermal stability. Glass fibre composites were fabricated by blending a DGEBA resin and the novel coloured epoxy resin and their mechanical properties, electrical properties and chemical resistance were studied.

Synthesis and Characterization of Novel Arylidene and Cardo Ester Bismaleimides and Poly(aminoaspartimide)s Therefrom

2003 ◽  
Vol 15 (3) ◽  
pp. 301-318 ◽  
Author(s):  
Vasile Cozan ◽  
Mitica Sava ◽  
Luminita Marin ◽  
Maria Bruma
Keyword(s):  
Thermal Stability ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Analysis Data ◽  
Synthesis And Characterization ◽  
Elemental Analysis Data ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
H Nmr

Six new bismaleimides (BMIs) having arylidene or cardo cycloaliphatic internal moieties were prepared by reacting 4-maleimidobenzoyl chloride with various arylidene or cardo bisphenols. The structures of BMIs were confirmed using elemental analysis data and spectroscopic (IR, 1H-NMR) characterizations. Two poly(aminoaspartimide)s (PAAs) were synthesized to exemplify one of the post-reaction abilities of the BMIs. Thermotropic liquid crystalline behavior was observed by differential scanning calorimetry and polarized light microscopy. The thermal stability of BMIs and PAAs was determined by thermogravimetric analysis and they showed good thermal stability except BMI 10, containing a cyclopentanone unit, which decomposed around 235°C. In this paper, we discuss the synthesis and characterization of these materials.

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