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.

Effect of Surface Characteristics on Polystyrene/Clay Nanocomposite via Emulsion Polymerization

2006 ◽  
Vol 111 ◽  
pp. 187-190 ◽  
Author(s):  
B.J. Park ◽  
Hyoung Jin Choi
Keyword(s):  
Emulsion Polymerization ◽  
Surface Characteristics ◽  
Clay Nanocomposites ◽  
X Ray Diffraction ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Transmission Electron ◽  
Organically Modified ◽  
Plate Geometry ◽  
Effect Of Surface

Polystyrene/clay nanocomposite with organically modified montmorillonite was synthesized via emulsion polymerization. Organic styrene monomer was first intercalated into intergalley of the clay hosts, followed by a typical emulsion polymerization with surfactant and initiator. To investigate the effect of clay loading, we also prepared PS/clay nanocomposites with different clay contents. Wide angle X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the emulsion polymerization of PS in the presence of clay produces partially exfoliated and intercalated nanocomposites. In order to study their rheological properties, the melt pallets of composite materials were prepared and measured via a rotational rheometer with a parallel plate geometry.

Optimisation of the ceramic-like body for ceramifiable EVA-based composites

2017 ◽  
Vol 24 (4) ◽  
pp. 599-607 ◽  
Author(s):  
Xinhao Gong ◽  
Tingwei Wang
Keyword(s):  
Ceramic Body ◽  
Ethylene Vinyl Acetate ◽  
Melt Blending ◽  
Red Phosphorus ◽  
X Ray Diffraction ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Dense Ceramic ◽  
Acetate Copolymer

AbstractVarious ceramifiable ethylene-vinyl acetate copolymer (EVA) composites were prepared by melt blending with two kinds of glass frits, organically modified montmorillonite (OMMT) and whitened and capsulised red phosphorus (WCRP). The influence of different filler components and firing temperatures on the ceramifiable properties of the composites was studied. The dripping behaviour of the composites was analyzed by a vertical burning test. The microstructure of the residues was characterised by X-ray diffraction (XRD) and scanning electron microscopy. The results showed that the optimised EVA composite was free of melt dripping during burning with the addition of OMMT. A dimensionally stable and dense ceramic residue was also obtained, especially with the addition of WCRP. It was suggested that new phases were formed at firing temperatures, and WCRP could promote the formation of ceramic body which was not fused during firing at 900°C as evidenced by XRD.

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.

Preparation, Physical and Mechanical Characterization of Montmorillonite/Polyethylene Nanocomposites

2006 ◽  
Vol 312 ◽  
pp. 205-210 ◽  
Author(s):  
V. Pettarin ◽  
Victor Jayme Roget Rodriguez Pita ◽  
Francisco Rolando Valenzuela-Díaz ◽  
S. Moschiar ◽  
L. Fasce ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Clay Platelet ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

In this paper, we report the preparation of polyethylene composites with organically modified montmorillonite. Three different Na+-montmorillonites were modified in order to obtain organoclays and two grades of high-density polyethylene were used as composite matrices. All composites were prepared by melt blending, and their physical and mechanical properties were thoroughly characterized. The extent of clay platelet exfoliation in the composites was confirmed by X-ray diffraction (XRD). Mechanical properties under static and impact conditions were evaluated to assess the influence of the reinforcement on the properties of polyethylene.

Effects of Surface Properties of Montmorillonite for their Cytocompatibility

2016 ◽  
Vol 696 ◽  
pp. 80-84 ◽  
Author(s):  
Ko Nakanishi ◽  
Shigeaki Abe ◽  
Shuichi Yamagata ◽  
Yasuhiro Yoshida ◽  
Junichiro Iida
Keyword(s):  
Coupling Reaction ◽  
Diffraction Peak ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Silane Coupling ◽  
Organically Modified ◽  
Size And Morphology

We modified the surface of organically modified montmorillonite (OMMT) with the carboxyl group using the silane coupling reaction and assessed its characteristics and cytocompatibility. Scanning electron microscope observations show that while the size and morphology of the obtained OMMT (OMMT-COOH) was unchanged, the surface of OMMT-COOH was coarser than that of OMMT. Fourier transform infrared spectra showed characteristic strong peaks at 1210 and 1630 cm−1, corresponding to the peaks of the carboxyl group. X-ray diffraction analysis showed that the diffraction peak of OMMT-COOH corresponding to the (001) reflection was located at higher a 2θ value than that of OMMT. Results of the proliferation ratio and cell viability measurements indicated that the OMMT-COOH cytocompatibility is higher than that of OMMT. Based on these results, we conclude that cytocompatibility of montmorillonite would be improved by tuning the properties of the surface.

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. 

The Mechanical and Thermal Properties of Polyoxymethylene (POM)/Organically Modified Montmorillonite (OMMT) Engineering Nanocomposites Modified with Thermoplastic Polyurethane (TPU) Compatibilizer

2012 ◽  
Vol 714 ◽  
pp. 201-209 ◽  
Author(s):  
Agnieszka Leszczyńska ◽  
Krzysztof Pielichowski
Keyword(s):  
Thermal Properties ◽  
Formic Acid ◽  
Mass Loss ◽  
Thermoplastic Polyurethane ◽  
Layered Silicate ◽  
Thermal Stabilization ◽  
Mechanical And Thermal Properties ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified

In this work the effect of macromolecular polyurethane compatibilizer on the structure, mechanical and thermal properties of polyoxymethylene/organically modified montmorillonite (POM/OMMT) nanocomposites was investigated. The thermal stability of obtained systems was significantly enhanced by compatibilizer both in oxidative and inert atmosphere. The thermoanalytical methods (TG-FTIR and TG-MS) were used for identification of gaseous products of degradation. The results showed less intensive evolution of formaldehyde and formic acid during the thermal degradation of POM/TPU/OMMT nanocomposites. Both formaldehyde and formic acid had an autocatalytic effect on degradation of neat POM and POM/MMT nanocomposites, especially in the initial stage of the process. However, in the presence of TPU the monomer formed in depolymerization reaction was captured most probably by urethane linkage in a formylation process. The decreased concentration of catalytic agent is considered as a cause of the reduced rate of mass loss of POM/TPU/OMMT nanocomposites. Interestingly, during thermooxidative degradation the temperature of maximum rate of mass loss was shifted towards higher temperature more than it could be anticipated from the TGA results obtained for neat POM, POM/TPU blend and POM/OMMT nanocomposite material with corresponding contents of nanofiller and compatibilizer. It is likely that the mechanism of thermal stabilization may be also related to the physical barrier effect of layered silicate towards oxygen diffusion. Both chemical and physical mechanisms of stabilization are referred to the structure and interfacial area developed in nanocomposite materials and thus can be influenced by addition of a compatibilizer. The obtained POM/TPU/OMMT nanocomposites revealed higher impact strength as compared to POM/OMMT materials due to the presence of elastomeric domains facilitating the dissipation of impact energy.

Thermomechanical behavior of nanoclay filled TPU/PP blends

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Kannan ◽  
S.S. Bhagawan ◽  
Kuruvilla Joseph ◽  
Sabu Thomas
Keyword(s):  
Hard Segment ◽  
Thermoplastic Polyurethane ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Modifier ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Pp Blends

AbstractBoth ester- and ether- based thermoplastic polyurethane (TPU) nanocomposites were prepared by melt blending, using 3 wt % Cloisite 10A (organically modified montmorillonite clay) as the nanoscale reinforcement. The nanocomposites were subsequently melt-blended with polypropylene (PP) using maleic anhydride grafted polypropylene (MA-g-PP) as a compatibilizer (in the ratio of 70/30- TPU nano/PP, 70/25/5-TPU nano/PP/MA-g-PP). Besides giving substantial increase in modulus, tensile strength and other properties organoclay reinforcement functions as a surface modifier for TPU hard segment. X-ray diffraction studies revealed that compatibilization is further improved by introducing functionalized PP (MA-g-PP) in the organoclay containing blends. The blend system was evaluated by DSC, DMA, SEM, mechanical properties and Xray diffraction. The results indicate that the ester- TPU exhibited greater miscibility than ether-TPU. Abrasion resistance and water absorption were also better for compatibilised ester- TPU blends as compared to the ether-TPU materials.

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