Effect of surface functionalization on mechanical properties and decomposition kinetics of high performance polyetherimide/MWCNT nano composites

2016 ◽  
Vol 90 ◽  
pp. 147-160 ◽  
Author(s):  
Mohan Kumar Pitchan ◽  
Shantanu Bhowmik ◽  
Meera Balachandran ◽  
M. Abraham
Keyword(s):  
Mechanical Properties ◽  
Surface Functionalization ◽  
High Performance ◽  
Decomposition Kinetics ◽  
Nano Composites ◽  
Kinetics Of ◽  
Effect Of Surface

scholarly journals Studies on Sheet Explosive Formulation Based on Octahydro-1,3,5,7-Tetranitro-1,3,5,7-Tetrazocine and Hydroxyl Terminated Polybutadiene

2017 ◽  
Vol 67 (6) ◽  
pp. 617 ◽  
Author(s):  
Suresh Kumar Jangid ◽  
Mrityunjay Kumar Singh ◽  
Vasant Jadavji Solanki ◽  
Rabindra Kumar Sinha ◽  
Krothapalli Prabhakara Subrahmania Murthy
Keyword(s):  
Mechanical Properties ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Kinetic Method ◽  
Decomposition Kinetics ◽  
Thermal And Mechanical Properties ◽  
Binder System ◽  
Scanning Calorimetry ◽  
Velocity Of Detonation ◽  
Kinetics Of

<p class="p1">The effect of replacing hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) in HTPB-binder on the performance, sensitivity, thermal, and mechanical properties of the sheet explosive formulation has been studied. The maximum loading of HMX was achieved up to 78 per cent in HTPB-binder system. The velocity of detonation (VOD) of HMX-based sheet explosive was observed about 7300 m/s which is marginally higher than existing RDX-based sheet explosive formulation (RDX/HTPB-binder, 80/20). The VOD trends were verified by theoretical calculation by BKW code using FORTRAN executable program. The thermal decomposition kinetics of sheet explosive formulations was investigated by differential scanning calorimetry. The activation energy for sheet explosive formulation HMX/HTPB-binder (78/22) was calculated using Kissinger kinetic method and found to be 170.08 kJ/mol, infer that sheet explosive formulation is thermally stable.</p>

INFLUENCE OF DIANILINE CROSS-LINKING SYSTEMS ON THE STRUCTURE, CURING MECHANISM, AND PROPERTIES OF POLYACRYLICESTER ELASTOMER

2018 ◽  
Vol 91 (4) ◽  
pp. 729-750 ◽  
Author(s):  
Tuhin Saha ◽  
Anil K. Bhowmick ◽  
Takeshi Oda ◽  
Toshiaki Miyauchi ◽  
Nobuhiko Fujii
Keyword(s):  
Mechanical Properties ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Density Functional ◽  
Functional Theory ◽  
Spectroscopic Analyses ◽  
Curing Mechanism ◽  
Temperature Superposition ◽  
Kinetics Of ◽  
Kinetics Of Vulcanization

ABSTRACT To develop high-performance polyacrylicester (ACM) elastomeric components with higher scorch safety and superior thermal and mechanical properties, we replaced aliphatic diamine curatives with aromatic dianiline curatives. The influence of dianiline curatives 4,4′-(4,4′-isopropylidenediphenyl-1,1′-diyldioxy)dianiline, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline, and 4,4′-(1,1′-biphenyl-4,4′-diyldioxy)dianiline on the network structures and thermal, dynamic mechanical, and mechanical properties of ACM vulcanizates was investigated. The kinetics of vulcanization was analyzed for different dianiline curatives, with the use of rheometer curves. To understand the electronic properties and study the relation between chemical structure and reactivity, density functional theory was used. The time–temperature superposition principal was used to evaluate the activation energy for degradation of cross-linked samples. Finally, the curing mechanism of ACM in the presence of dianiline curative was studied with X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. These spectroscopic analyses suggested that the reaction mechanism took place via two steps: the first step was formation of the amide linkage and the second step was formation of imide linkages.

scholarly journals Dry-Jet Wet Spinning of Thermally Stable Lignin-Textile Grade Polyacrylonitrile Fibers Regenerated from Chloride-Based Ionic Liquids Compounds

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3687
Author(s):  
Muhannad Al Aiti ◽  
Amit Das ◽  
Mikko Kanerva ◽  
Maija Järventausta ◽  
Petri Johansson ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Ionic Liquids ◽  
High Performance ◽  
Paper Industry ◽  
Mechanical Tests ◽  
Coagulation Bath ◽  
Scanning Calorimetry ◽  
The Impact ◽  
Kinetics Of

In this paper, we report on the use of amorphous lignin, a waste by-product of the paper industry, for the production of high performance carbon fibers (CF) as precursor with improved thermal stability and thermo-mechanical properties. The precursor was prepared by blending of lignin with polyacrylonitrile (PAN), which was previously dissolved in an ionic liquid. The fibers thus produced offered very high thermal stability as compared with the fiber consisting of pure PAN. The molecular compatibility, miscibility, and thermal stability of the system were studied by means of shear rheological measurements. The achieved mechanical properties were found to be related to the temperature-dependent relaxation time (consistence parameter) of the spinning dope and the diffusion kinetics of the ionic liquids from the fibers into the coagulation bath. Furthermore, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical tests (DMA) were utilized to understand in-depth the thermal and the stabilization kinetics of the developed fibers and the impact of lignin on the stabilization process of the fibers. Low molecular weight lignin increased the thermally induced physical shrinkage, suggesting disturbing effects on the semi-crystalline domains of the PAN matrix, and suppressed the chemically induced shrinkage of the fibers. The knowledge gained throughout the present paper allows summarizing a novel avenue to develop lignin-based CF designed with adjusted thermal stability.

Surface Functionalization of Carbon Nanotubes and Compressive Strength of MWCNTs-OPC

2012 ◽  
Vol 511 ◽  
pp. 171-174 ◽  
Author(s):  
Fu Xia Wang ◽  
Yu Ying Wang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Surface Functionalization ◽  
High Performance ◽  
Multiwall Carbon Nanotubes ◽  
Reinforcing Effect ◽  
Cement Based Materials ◽  
Highly Dispersed ◽  
Functionalization Of Carbon Nanotubes ◽  
Multiwall Carbon

Due to their remarkable mechanical properties, carbon nanotubes (CNTs) are considered to be one of the most promising reinforcing materials for the next generation of high-performance cementitious composites. However, the major problem is the highly attractive van der Waals forces between CNTs, which create coherent agglomerates that prove difficult to disperse in cement based materials and reduce the fluidity of the fresh mixture. In this study, the reinforcing effect of highly dispersed multiwall carbon nanotubes (MWCNTs) at ratios of 0.05, 0.1, 0.15， 0.2 and 0.25wt.% of cement has been investigated. The results show that small amount of effectively dispersed MWCNTs can significantly increase the strength of the cementitious

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Mechanical properties and durability of high - performance concrete for bridge decks

PCI Journal ◽  
2008 ◽  
Vol 53 (4) ◽  
pp. 108-130
Author(s):  
Mohsen A. Issa ◽  
Atef A. Khalil ◽  
Shahidul Islam ◽  
Paul D. Krauss
Keyword(s):  
Mechanical Properties ◽  
High Performance ◽  
High Performance Concrete ◽  
Bridge Decks

Thermal Decomposition Kinetics of Torrefied Oil Palm Empty Fruit Bunch Briquettes

2016 ◽  
Vol 10 (3) ◽  
pp. 325-328 ◽  
Author(s):  
Bemgba Nyakuma ◽  
◽  
Arshad Ahmad ◽  
Anwar Johari ◽  
Tuan Abdullah ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Oil Palm ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetic Properties ◽  
Tg Analysis ◽  
Empty Fruit Bunches ◽  
Thermal Lag ◽  
Profile Characteristics ◽  
Kinetics Of

The study is aimed at investigating the thermal behavior and decomposition kinetics of torrefied oil palm empty fruit bunches (OPEFB) briquettes using a thermogravimetric (TG) analysis and the Coats-Redfern model. The results revealed that thermal decomposition kinetics of OPEFB and torrefied OPEFB briquettes is significantly influenced by the severity of torrefaction temperature. Furthermore, the temperature profile characteristics; Tonset, Tpeak, and Tend increased consistently due to the thermal lag observed during TG analysis. In addition, the torrefied OPEFB briquettes were observed to possess superior thermal and kinetic properties over the untorrefied OPEFB briquettes. It can be inferred that torrefaction improves the fuel properties of pelletized OPEFB for potential utilization in bioenergy conversion systems.

Thermal Decomposition Kinetics of Glyphosate (GP) and its Metabolite Aminomethylphosphonic Acid (AMPA)

2019 ◽  
Author(s):  
Milad Narimani ◽  
Gabriel da Silva
Keyword(s):  
Thermal Decomposition ◽  
Reaction Rate ◽  
Decomposition Kinetics ◽  
Rate Theory ◽  
Thermal Decomposition Mechanism ◽  
Treatment Processes ◽  
Aminomethylphosphonic Acid ◽  
Reaction Rate Theory ◽  
Decomposition Chemistry ◽  
Kinetics Of

Glyphosate (GP) is a widely used herbicide worldwide, yet accumulation of GP and its main byproduct, aminomethylphosphonic acid (AMPA), in soil and water has raised concerns about its potential effects to human health. Thermal treatment processes are one option for decontaminating material containing GP and AMPA, yet the thermal decomposition chemistry of these compounds remains poorly understood. Here, we have revealed the thermal decomposition mechanism of GP and AMPA by applying computational chemistry and reaction rate theory methods. <br>

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