scholarly journals Synthesis of Poly(cyclohexene oxide)-Montmorillonite Nanocomposite viaIn SituPhotoinitiated Cationic Polymerization with Bifunctional Clay

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Işıl Bayram ◽  
Ayhan Oral ◽  
Kamil Şirin

Poly(cyclohexene oxide) (PCHO)/clay nanocomposites were prepared by means ofin situ photoinitiated cationic polymerizationwith initiator moieties immobilized within the silicate galleries of the clay particles. Diphenyliodonium molecules were intercalated via cation exchange process between Cloisite Ca and diphenyliodonium. The polymerization of CHO through the interlayer galleries of the clay can provide a homogenous distribution of the clay layers in the polymer matrix in nanosize and results in the formation of PCHO/clay nanocomposites. The rates of clay loadings were changed to 1%, 3%, and 5% so as to investigate the effect of clay and initiator amount on polymer. X-ray diffraction (XRD) spectroscopy, thermogravimetric analysis (TGA), and transmission electron microscopy (TEM) methods were used for the characterization of modified clay and nanocomposite materials. Thermal stability of PCHO/MMT nanocomposites was also studied by both differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
E. M. Araújo ◽  
K. D. Araujo ◽  
R. A. Paz ◽  
T. R. Gouveia ◽  
R. Barbosa ◽  
...  

Polyamide 66 (PA66)/Brazilian clay nanocomposites were produced via direct melt intercalation. A montmorillonite sample from the Brazilian state of Paraíba was organically modified with esthearildimethylammonium chloride (Praepagen), quaternary ammonium salt and has been tested to be used in polymer nanocomposites. The dispersion analysis and the interlayer spacing of the clay particles in matrix were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermal behavior of the obtained systems was investigated by differential scanning calorimetry (DSC), thermogravimetry (TG), and heat deflection temperature (HDT) was reported too. The nanocomposites exhibited a partially exfoliated structure, very interesting HDT values which are higher than those of pure PA66, and good thermal stability.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Limei Wang ◽  
Aihua He

Polypropylene (PP)/clay nanocomposites were synthesized by in situ intercalative polymerization with TiCl4/MgCl2/clay compound catalyst. Microstructure and thermal properties of PP/clay nanocomposites were studied in detail. Fourier transform infrared (FTIR) spectra indicated that PP/clay nanocomposites were successfully prepared. Both wide-angle X-ray diffraction (XRD) and transmission electron microscopy (TEM) examination proved that clay layers are homogeneously distributed in PP matrix. XRD patterns also showed that theαphase was the dominate crystal phase of PP in the nanocomposites. Thermogravimetric analysis (TGA) examinations confirmed that thermal stability of PP/clay nanocomposites was markedly superior to pure PP. Differential scanning calorimetry (DSC) scans showed that the melt temperature and the crystallinity of nanocomposites were slightly lower than those of pure PP due to crystals imperfections.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1397 ◽  
Author(s):  
Elaine dos Santos ◽  
Marcus Fook ◽  
Oscar Malta ◽  
Suédina de Lima Silva ◽  
Itamara Leite

Purified clay was modified with different amounts of alkyl ammonium and phosphonium salts and used as filler in the preparation of PET nanocomposites via melt intercalation. The effect of this type of filler on morphology and thermal and mechanical properties of PET nanocomposites was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile properties, and transmission electron microscopy (TEM). The results showed that the mixture of alkyl ammonium and phosphonium salts favored the production of PET nanocomposites with intercalated and partially exfoliated morphologies with slight improvement in thermal stability. In addition, the incorporation of these organoclays tended to inhibit PET crystallization behavior, which is profitable in the production of transparent bottles.


2020 ◽  
pp. 096739112093205
Author(s):  
Maider Iturrondobeitia ◽  
Julen Ibarretxe ◽  
Pello Jimbert ◽  
Roberto Fernandez-Martínez

The objective of performing transmission electron microscopy (TEM) tomography (TEMT) on poly (lactic acid) (PLA)/clay samples is to characterize their 3D microstructure by obtaining the dispersion distribution and orientation of the dimensions of the clays. This information cannot be elucidated from a qualitative TEM analysis or from conventional characterization techniques such as X-ray diffraction. The nanocomposites are obtained by mixing PLA with Cloisite 20A and 30B at different extrusion shear rates which have been analyzed in 3D. Quantitative TEMT is performed to all the nanocomposites and the resulting 3D quantitative characterization (geometry of clay particles misalignment degree and distribution) is used for a more realistic comprehension of the mechanical behavior of the nanocomposites.


2008 ◽  
Vol 8 (4) ◽  
pp. 1937-1941
Author(s):  
R. Barbosa ◽  
E. M. Araújo ◽  
T. J. A. Melo ◽  
E. N. Ito ◽  
E. Hage

High density polyethylene/Brazilian clay nanocomposites were prepared by the melt intercalation technique. A montmorillonite sample from Boa Vista/PB, Northeast of Brazil, was organically modified with esthearildimethylammonium chloride (Praepagen WB) quaternary ammonium salt. The unmodified and modified clays with the quaternary ammonium salt were introduced in 1, 2, 3 and 5 wt% in a PE polymer matrix. The dispersion analysis and the interlayer distance of the clay particles were obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The mechanical properties of tensile and the flammability of the nanocomposites were studied. In general, the mechanical properties of the systems presented superior values compared to the matrix. The systems showed a reduction on the burning rate, indicating that the flammability resistance of nanocomposites was improved.


2013 ◽  
Vol 647 ◽  
pp. 701-704 ◽  
Author(s):  
Rihayat Teuku ◽  
Amroel Suryani

An organically modified clay and a pristine clay were used to prepare biodegradable thermoplastic polyurethane (PU) paint/clay nanocomposites. In this paper, polyurethane paint /clay nanocomposites base on palm oil polyol were prepared by isocyanate, polyol and organoclay (a clay modified with Cetyl trimethyl ammonium Bromide (CTAB) and Octadecylamines (ODA). The morphologies of samples were revealed by transmission electron microscopy (TEM) and Intercalation of PU into clay galleries and crystalline structure of PU were investigated using X-ray diffraction (XRD). The morphology of the resulting composite showed a combination of intercalated and partially exfoliated clay layers with occasional clay aggregates


2006 ◽  
Vol 05 (02n03) ◽  
pp. 291-297 ◽  
Author(s):  
ZHIYI ZHANG ◽  
NING ZHAO ◽  
WEI WEI ◽  
DONG WU ◽  
YUHAN SUN

Poly(butyl acrylate-co-methyl methacrylate)/clay nanocomposites were synthesized via emulsion polymerization with an emulsifier (sodium dodecyl benzene sulfonate, SDBS), an initiator (ammonium persulate, APS), acrylic acid ester monomer and Na -montmorillonite. It was found that the addition of SDBS and water widened the gap between clay layers and facilitated monomers to penetrate into clay. Through initiator, comonomers were polymerized in the montmorillonite galleries. The structure of extracted nanocomposites was confirmed by XRD, transmission electron microscopy (TEM). Their thermal property and molecule weight were investigated by differential scanning calorimetry (DSC) and gel-penetrate chromatogram (GPC).


2011 ◽  
Vol 55-57 ◽  
pp. 1584-1587 ◽  
Author(s):  
Li Mei Wang

Polypropylene(PP)/clay nanocomposites were prepared by solution blending. The microstructure of PP/clay nanocomposites was studied by wide-angle X-ray diffraction (XRD) analysis. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to investigate thermal properties of PP/clay nanocomposites. XRD pattern prove that clay layers were exfoliated into nanometer size in PP matrix and that α-Phase crystallite was the main crystallite of PP in PP/clay nanocomposites. TGA examinations confirmed that the maximum decomposition temperature of PP/clay nanocomposites was higher than that of neat PP and that the thermal stability of PP/clay nanocomposites rose noticeably. Results of DSC scans showed the crystalliztion temperature of nanocomposites was slightly bigger than that of pure PP due to the efficient nucleating effects of clay layers.


2012 ◽  
Vol 622-623 ◽  
pp. 847-850
Author(s):  
Sedigheh Bagheri-Kazemabad ◽  
Alireza Khavandi ◽  
Daniel Fox ◽  
Yan Hui Chen ◽  
Hong Zhou Zhang ◽  
...  

Polypropylene (PP)/clay nanocomposites were prepared via a melt mixing technique. Two types of compatibilizers, namely poly (ethyleneco-octene) (EOC-g-MA) and polypropylene grafted maleic anhydride (PP-g-MA), were selected to facilitate the nanocomposite formation. X-ray diffraction and transmission electron microscopy in conjunction with rheological analysis were used for studying the dispersion state of clay layers in these nanocomposites. The results showed with the introduction of EOC-g-MA to PP/clay, clay was dispersed better than the presence of PP-g-MA.


2020 ◽  
pp. 089270572093917 ◽  
Author(s):  
Lahouari Mrah ◽  
Rachid Meghabar

This work is mainly concentrated on the preparation and characterization of poly(propylene oxide) (PPO)/organic clay nanocomposites. The effects of the nature of organoclays and the method of preparation have been elucidated to evaluate their morphological, structural and thermal properties. These nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, thermal analysis (differential scanning calorimetry) and thermogravimetric analysis (TGA). This study involved the use of an Algerian clay called ‘maghnite’ which was modified by an incorporation method using different concentrations of the surfactant cetyltrimethylammonium bromide (CTAB). Propylene oxide (PO) was polymerized in the presence of ethylene glycol and various proportions of organic clay ranging from 1%, 5% and 10% by weight. The structural study by XRD showed, at different loading rates of maghnite and PO in the preparation of PPO/maghnite nanocomposites, different morphologies: intercalated/exfoliated blend and intercalated/agglomerated. TGA showed that the intercalation of PPO at the montmorillonite (MMT)-CTA interface would be more advantageous since the required amount of 5% organic clay (by weight) ensures high thermal stability of the nanocomposites, and the glass transition temperature ( T g) of PPO/MMT nanocomposites is higher than that of PPO since this increase is due to the introduction of clay into the matrix which makes the nanocomposite more rigid.


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