scholarly journals Effects of Hybridized Organically Modified Montmorillonite and Cellulose Nanocrystals on Rheological Properties and Thermal Stability of K-Carrageenan Bio-Nanocomposite

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1547 ◽  
Author(s):  
Siti Zarina Zakuwan ◽  
Ishak Ahmad
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Cellulose Nanocrystals ◽  
Nanocomposite Films ◽  
Morphological Properties ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
The Matrix ◽  
Thermal Stability Of

Herein, hybrid k-carrageenan bio-nanocomposite films were fabricated by using two types of nanofillers, organically modified montmorillonite (OMMT), and cellulose nanocrystals (CNCs). Hybrid bio-nanocomposite films were made by casting techniques employing 4 wt% of CNCs, OMMT, and hybridized CNCs/OMMT in a 1:1 ratio. The rheological and morphological properties and thermal stability of all composites were investigated using rotational rheometry, thermogravimetry analysis, differential scanning calorimetry, field emission scanning electron microscopy, and transmission electron microscopy (TEM). The results showed that the hybrid CNC/OMMT bio-nanocomposite exhibited significantly improved properties as compared to those for the bio-nanocomposites with single fillers due to the nanosize and homogenous nanofiller dispersion in the matrix. Rheological analysis of the hybrid bio-nanocomposite showed higher dynamic shear storage modulus and complex viscosity values when compared to those for the bio-nanocomposite with individual fillers. The TEM analysis of the hybridized CNC/OMMT bio-nanocomposite revealed that more particles were packed together in the CNC network, which restricted the matrix mobility. The heat resistance and thermal stability bio-nanocomposite k-carrageenan film enhanced rapidly with the addition of hybridized CNCs/OMMT to 275 °C. The hybridized CNCs/OMMT exhibited synergistic effects due to the good affinity through interfacial interactions, resulting in the improvement of the material properties.

Characterization of Nanoclay Modified Polycarbonate Blend with Secondary Acrylonitrile Butadiene Styrene Terpolymer

2016 ◽  
Vol 674 ◽  
pp. 173-178
Author(s):  
Remo Merijs Meri ◽  
Janis Zicans ◽  
Tatjana Ivanova ◽  
Rita Berzina ◽  
Ruta Saldabola ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Tensile Properties ◽  
Acrylonitrile Butadiene Styrene ◽  
Engineering System ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Thermal Stability Of ◽  
Butadiene Styrene

Acrylonitrile butadiene styrene (ABS) terpolymer is one of the major plastics in IT equipment waste stream. In the current research secondary ABS (s-ABS) is blended with polycarbonate (PC) by forming one of the most popular thermoplastics engineering system. The effect of organically modified montmorillonite clay (OMMT) on the tensile properties and thermal stability of PC+10wt.%s-ABS blend is investigated. Increase in stiffness, strength and thermal stability is observed along with rising OMMT content. Highest increments of the aforementioned properties are observed within the OMMT range of 1-1,5 wt.%.

An easy approach to fabricating HgS/chitosan nanocomposite films and their ability to sense triethylamine

2014 ◽  
Vol 34 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Shan Wang ◽  
Minyan Zheng
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Fluorescence Emission ◽  
Nanocomposite Films ◽  
Scanning Calorimetry ◽  
Sem Image ◽  
Thermal Stability Of ◽  
Scanning Electron

Abstract A chitosan (CS)–HgS nanocomposite was synthesized by a simulating biomineralization method. The effect of HgS nanoparticles on the physical properties of the composite was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The glass transition temperature (Tg) of the composite was 22°C higher than that of CS. The thermal stability of the composite was higher than that of CS, which was evidenced by the shift of onset temperature of degradation by 22°C as measured by DSC. The SEM image of the HgS/CS nanocomposite film shows that the nanoparticle size was 100 nm. The fluorescence emission of nanocomposite films was found to be very sensitive to the presence of triethylamine; even a small amount of triethylamine dramatically increased emissions. By contrast, emission was hardly affected by other common ions in water. The films are predicted to have the potential to be developed into excellent sensing films for triethylamine.

scholarly journals Synergistic Effect of Hybridized Cellulose Nanocrystals and Organically Modified Montmorillonite on κ-Carrageenan Bionanocomposites

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 874 ◽  
Author(s):  
Siti Zakuwan ◽  
Ishak Ahmad
Keyword(s):  
Synergistic Effect ◽  
Water Uptake ◽  
Cellulose Nanocrystals ◽  
Food Packaging ◽  
Filler Loading ◽  
X Ray Diffraction ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
And Performance

The synergistic effect of using κ-carrageenan bionanocomposites with the hybridization of cellulose nanocrystals (CNCs) and organically modified montmorillonite (OMMT) reinforcements was studied. The effects of different reinforcements and filler contents were evaluated through mechanical testing, and morphological and water uptake properties. The tensile strength and Young’s modulus of both bionanocomposites increased with filler loading and optimized at 4%. OMMT incorporation into the κ-carrageenan/CNCs bionanocomposites resulted in further mechanical property improvement with an optimum ratio of 1:1 (CNCs:OMMT) while maintaining high film transparency. X-ray diffraction and morphological analyses revealed that intercalation occurred between the κ-carrageenan bionanocomposite matrix and OMMT. The water uptake of the κ-carrageenan bionanocomposites was significantly reduced by the addition of both CNCs and OMMT. The enhancements in the mechanical properties and performance of the hybrid bionanocomposite indicate compatibility among the reinforcement, biopolymer, and well-dispersed nanoparticles. This renders the hybrid CNC/OMMT/κ-carrageenan nanocomposites extremely promising for food packaging applications.

scholarly journals Preparation of Polyimide-Clay Nanocomposites and Their Performance

2009 ◽  
Vol 1 (2) ◽  
pp. 326-333 ◽  
Author(s):  
S. M. M. Alam
Keyword(s):  
Tensile Modulus ◽  
Clay Nanocomposites ◽  
Gravimetric Analysis ◽  
Modified Clay ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Layered Clay ◽  
Tetracarboxylic Dianhydride ◽  
Thermal Stability Of

A series of polyimide (PI)-organically modified clay nanocomposites were made to enhance tensile modulus, thermal stability of PI. PI was made from 3, 3', 4, 4'-biphenyl tetracarboxylic dianhydride (BPDA), p-phenylediamine (PDA).  Montmorillonite (MMT), one type of layered clay, was treated by dodecylamine salt.  XRD indicated that organically modified montmorillonite (OMMT) layers were exfoliated and dispersed into PI-film.  Tensile measurements indicated that small amount of OMMT (up to 3%) increased tensile modulus nicely.  The glass transition temperatures (Tg) of the nano-composites are higher than those of pristine PI.  Thermal gravimetric analysis (TGA) showed that nanocomposites have higher decomposition temperatures in comparison with the original PI.  Keywords: Polyimide; Organically modified clay; Nanocomposites; Dodecylamine. © 2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.DOI: 10.3329/jsr.v1i2.2297

scholarly journals Investigations of the Montmorillonite and Aluminium Trihydrate Addition Effects on the Ignitability and Thermal Stability of Asphalt

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kai Zhu ◽  
Ke Wu ◽  
Bin Wu ◽  
Zhiyi Huang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Thermal Stability Of

By means of limiting oxygen index (LOI), cone calorimeter, and TG-DSC tests, this paper investigated the effect of unmodified montmorillonite (MMT), organically modified montmorillonite (OMMT), and aluminium trihydrate (ATH) additions on the flame retardancy for asphalt combustion. Experimental results showed that adding a small amount of montmorillonite did not significantly increase the oxygen index of the asphalt but reduced the heat release rate during asphalt combustion. TGA tests had indicated that the montmorillonite (MMT and OMMT) could suppress the release of flammable volatiles and form more asphaltenes, which hence postponed the burnout time of asphalt. Furthermore, the combination of montmorillonite (MMT and OMMT) and ATH had yielded a synergistic effect, which had further reduced the heat release rate and also increased the oxygen index of asphalt. In particular, after further addition of OMMT, the barrier layer showed less crack, leading to a significant decrease in the heat release rate as compared to the adding of ATH alone.

scholarly journals Effects of Ultrasonication Time on Thermal Stability and Swelling Behaviour of The Commercial Organo-Montmorillonite (O-MMT)

2018 ◽  
Vol 7 (2.23) ◽  
pp. 288 ◽  
Author(s):  
Asna R.A. Hamid ◽  
Azlin F. Osman
Keyword(s):  
Thermal Stability ◽  
Interlayer Spacing ◽  
Water Medium ◽  
Melt Compounding ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Polymer Clay Nanocomposite ◽  
Organically Modified ◽  
Ultrasonication Time ◽  
Stability Enhancement

In this contribution, we report the effect of ultrasonication time on thermal stability and swelling of organically modified montmorillonite (O-MMT) upon ultrasonication in a water medium. In the production of well-exfoliated polymer/clay nanocomposite, ultrasonication was employed as a method to exfoliate and disperse organically modified montmorillonite (O-MMT) platelets prior to melt compounding with the polymer matrix. The suspension of distilled water and O-MMT was magnetically stirred for 2 hours and then ultrasonicated at the different sonicating time, namely, 2 minutes, 5 minutes, 10 minutes, 15 minutes and 20 minutes (min) at room temperature. Thermogravimetry analysis (TGA) suggested that dispersion of the O-MMT by ultrasonication for 5 minutes resulted in thermal stability enhancement without destruction of the organic surface modifier structure and bonding on the clay platelets. X-ray diffraction (XRD) also indicated that application of 5 minutes ultrasonication time has most obviously improved the swelling of the O-MMT platelets. This was further proved by Field emission scanning electron microscope (FeSEM) which revealed greater interlayer spacing within the O-MMT platelets was obtained. 

scholarly journals Thermal Stability and Degradation Kinetics of Polystyrene/Organically-Modified Montmorillonite Nanocomposites

2008 ◽  
Vol 8 (4) ◽  
pp. 1927-1936 ◽  
Author(s):  
Grace Chigwada ◽  
Everson Kandare ◽  
Dongyan Wang ◽  
Stephen Majoni ◽  
Darlington Mlambo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Mass Loss ◽  
Degradation Kinetics ◽  
X Ray Diffraction ◽  
Cone Calorimetry ◽  
Model Free ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Transmission Electron ◽  
Organically Modified

Organically-modified montmorillonite (MMT) clays have been prepared using ammonium salts containing quinoline, pyridine, benzene, and styrenic groups. The nanocomposites were prepared by melt blending and the formation of nanocomposites was characterized using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermal stability and flammability were evaluated by thermogravimetric analysis (TGA) and cone calorimetry measurements, respectively. The presence ofmodified MMT at 5% loading resulted in significant improvement in thermal stability compared to the virgin polymer. Effective activation energies for mass loss were determined via a model-free isoconversional approach from TGA data obtained under N2 and under air. The additives served to raise the activation energy, with a more significant impact observed under pyrolysis conditions. The onset temperature of degradation and temperature of maximum decomposition rate are increased, while the peak heat release rate and mass loss rates are significantly reduced in the presence of three of the modified clays. No reduction in the total heat released is observed.

scholarly journals Mechanical and thermal stability of retained austenite in plastically deformed bainite-based TRIP-aided medium-Mn steels

2021 ◽  
Vol 21 (3) ◽  
Author(s):  
Aleksandra Kozłowska ◽  
Adam Grajcar ◽  
Aleksandra Janik ◽  
Krzysztof Radwański ◽  
Ulrich Krupp ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Retained Austenite ◽  
Elevated Temperatures ◽  
Mechanical Performance ◽  
Mechanical Stability ◽  
Electron Backscatter Diffraction ◽  
Cost Effective ◽  
Tensile Tests ◽  
Thermal Stability Of

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.

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