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

2017 ◽  
Vol 24 (4) ◽  
pp. 599-607 ◽  
Author(s):  
Xinhao Gong ◽  
Tingwei Wang

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.

2006 ◽  
Vol 312 ◽  
pp. 205-210 ◽  
Author(s):  
V. Pettarin ◽  
Victor Jayme Roget Rodriguez Pita ◽  
Francisco Rolando Valenzuela-Díaz ◽  
S. Moschiar ◽  
L. Fasce ◽  
...  

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.


e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
M. Kannan ◽  
S.S. Bhagawan ◽  
Kuruvilla Joseph ◽  
Sabu Thomas

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.


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 874 ◽  
Author(s):  
Siti Zakuwan ◽  
Ishak Ahmad

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.


2016 ◽  
Vol 696 ◽  
pp. 80-84 ◽  
Author(s):  
Ko Nakanishi ◽  
Shigeaki Abe ◽  
Shuichi Yamagata ◽  
Yasuhiro Yoshida ◽  
Junichiro Iida

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.


2008 ◽  
Vol 8 (4) ◽  
pp. 1927-1936 ◽  
Author(s):  
Grace Chigwada ◽  
Everson Kandare ◽  
Dongyan Wang ◽  
Stephen Majoni ◽  
Darlington Mlambo ◽  
...  

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.


2006 ◽  
Vol 111 ◽  
pp. 187-190 ◽  
Author(s):  
B.J. Park ◽  
Hyoung Jin Choi

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.


Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2996 ◽  
Author(s):  
Lenka Pazourková ◽  
Magda Reli ◽  
Marianna Hundáková ◽  
Erich Pazdziora ◽  
Daniela Predoi ◽  
...  

Novel biomedical composites, based on organically modified vermiculite and montmorillonite with deposited Ca-deficient hydroxyapatite (CDH), were prepared. The monoionic sodium forms of vermiculite and montmorillonite were intercalated with chlorhexidine diacetate (CA). The surfaces of organoclays were used for the precipitation of Ca-deficient hydroxyapatite. The composites with Ca-deficient hydroxyapatite showed very good antibacterial effects, similar to the antimicrobial activity of pure organoclay samples. Better antibacterial activity was shown in the organically modified montmorillonite sample with Ca-deficient hydroxyapatite compared with the vermiculite composite, but, in the case of Staphylococcus aureus, both composites showed the same minimum inhibitory concentration (MIC) value. The antimicrobial effect of composites against bacteria and fungi increased with the time of exposure. The structural characterization of all the prepared materials, performed using X-ray diffraction and FT infrared spectroscopy analysis, detected no changes in the original clay or CDH during the intercalation or precipitation process, therefore we expect the strength of the compounds to be in the original power.


e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Sinan Sen ◽  
Nihan Nugay ◽  
Turgut Nugay

Abstract 4-Vinylpyridine monomer was mixed with organically modified montmorillonite (MMT) and polymerized in the presence of 2,2’-azoisobutyronitrile as radical initiator. Organophilic montmorillonite was obtained by using a block copolymer of poly(methyl methacrylate) and quaternized poly(4-vinylpyridine) (P4VP) in different compositions. X-ray diffraction (XRD) and thermogravimetric analysis confirmed that the block copolymer is inserted between MMT layers while the interlayer distance is expanded. The P4VP nanocomposites obtained from the block copolymer with the longer P4VP block exhibited no XRD peak, suggesting an exfoliated structure. These composites showed increased storage modulus and thermal stability at a very low loading of 1 - 2 wt.-%, compared to neat P4VP. Scanning electron microscopy and atomic force microscopy analyses were also conducted for selected nanocomposites.


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