scholarly journals Pit and fissure nanocomposite sealants reinforced with organically modified montmorillonite: A study of their mechanical properties, surface roughness and color stability

2020 ◽  
Vol 39 (5) ◽  
pp. 773-783 ◽  
Author(s):  
Alexandros NIKOLAIDIS ◽  
Triantafyllia VOUZARA ◽  
Elisabeth KOULAOUZIDOU
2002 ◽  
Vol 740 ◽  
Author(s):  
Pralay Maiti ◽  
Carl A. Batt ◽  
Emmanuel P. Giannelis

ABSTRACTNanocomposites of α-hydroxy polyester, polylactide (PLA) and β-hydroxy polyester, polyhydroxybutyrate (PHB) with layered silicates have been successfully prepared by melt extrusion of PLA and PHB with organically modified montmorillonite (MMT) and fluoromica. The mechanical properties of the nanocomposites are improved compared to the neat polymers. Storage modulus increase up to 40% compared with the pure polymers by adding only 2–3 wt% nanoclay. Biodegradation can be controlled by the choice of the nanoclay used.


2009 ◽  
Vol 151 ◽  
pp. 129-134 ◽  
Author(s):  
Onur Yılmaz ◽  
Aurica P. Chiriac ◽  
Catalina Natalia Cheaburu ◽  
Loredana E. Nita ◽  
Gürbüz Gülümser ◽  
...  

Nanocomposites based on layered silicate organically modified montmorillonite (Cloisite 20A) and acrylic comonomers (butyl acrylate and methyl methacrylate) were prepared by simple “in situ” batch emulsion polymerization method. The particle size and zeta potential of the emulsions were analyzed. The structural characterizations of the nanocomposites were performed by FTIR, thermal behaviors of the films were investigated by DSC, mechanical properties of the films were tested by DMA and intercalation success was viewed by XRD. The mechanical properties of the nanocomposites were improved significantly especially at the temperatures above Tg. The ultrasonication process was found to be useful for increasing the homogeneity of the emulsions and intercalation success. The obtained nanocomposite emulsions were applied on garment leathers in a finishing formulation as aqueous binders sharing good film forming ability and elasticity.


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.


2012 ◽  
Vol 31 (5) ◽  
pp. 341-350 ◽  
Author(s):  
Hossein Khanjanzadeh ◽  
Taghi Tabarsa ◽  
Alireza Shakeri

Several composites based on recycled—virgin polypropylene, wood flour and organically modified montmorillonite (commonly called ‘nanoclay’) were prepared by melt compounding. This paper aims to evaluate the potential for the use of recycled polypropylene and underutilized wood flour as material for the development of wood–plastic composites, as well as reinforcement effect of organically modified montmorillonite on them. In order to improve the poor interfacial interaction between the hydrophilic wood flour and hydrophobic polypropylene matrix, as well as polypropylene–organically modified montmorillonite, maleic anhydride-grafted polypropylene was used as a compatibilizer. Some mechanical and physical properties were evaluated. Findings of this work show that both recycled and virgin polypropylene can be used in manufacture of wood–plastic composites and there is no significant difference in the properties of resulting nanocomposites. It was found that mechanical properties of polypropylene containing 40wt% wood flour reinforcement remain essentially unchanged when the virgin polypropylene in the matrix is replaced be recycled polypropylene. Morphologies of the nanocomposites were analyzed by scanning electron microscopy and X-ray diffraction, and the results showed increased d-spacing of clay layers indicating enhanced compatibility between polypropylene and clay and wood flour. Consequently, polypropylene recycled from postconsumer applications can be used in high-value nanocomposites without going the expense of separating out impurities from the polymer.


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