scholarly journals STRUCTURES AND PROPERTIES OF NATURAL RUBBER/ORGANOCLAY NANOCOMPOSITES

2011 ◽  
Vol 14 (1) ◽  
pp. 30-38
Author(s):  
Hien Quang Pham ◽  
Son Thanh Thanh Do ◽  
Nieu Huu Nguyen

Natural rubber (NR), 30% epoxidized natural rubber (ENR30) and organoclays (Nanomer I28E and I30E) are blended in Brabender. Dispersions of the organoclay in NR are investigated by X – ray diffraction (XRD) and scanning electron microscopy (SEM). The results revealed the increase of dispersion efficiency by the addition of ENR30 as a compatibilizer. The existence of organoclay I28E reduces the vulcanization time, while torque value increases slightly and mechanical properties (abrasion resistance, modulus M100, modulus M300, tensile strength, tear strength) are improved considerably.

Author(s):  
Vineet Chak ◽  
Himadri Chattopadhyay ◽  
Md. Mahfooz Alam

In present study an effort has been made to investigate the effect of changing the mode of mold cavity filling on mechanical properties and microstructure of cast aluminium. The pouring of the melt in mold cavity is avoided so as to check defects associated with it and instead of pouring, counter gravity filling of mold technique is utilized. The obtained properties and microstructure are compared with gravity poured (traditionally cast) aluminium. Characterization techniques like optical microscopy, scanning electron microscopy, X-Ray diffraction and mechanical testing like tensile and hardness of the cast samples is carried out. Hardness and tensile strength reported an increment of 22.37% and 26.71% respectively as compared to traditionally cast specimens. This enhancement in mechanical properties was attributed to improved microstructure obtained.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.


2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Ruy A. Sá Ribeiro ◽  
Marilene G. Sá Ribeiro ◽  
Gregory P. Kutyla ◽  
Waltraud M. Kriven

To determine the viability of using a local resource for geopolymer synthesis, geopolymers were synthesized using metakaolin made from clay mined in the Amazonian region of Brazil. Samples were made with mixed potassium-sodium and pure sodium metakaolin-based geopolymer. Samples were also made using commercial metakaolin (CMK) from BASF, Inc. as a comparison to the Amazonian metakaolin (AMK). Scanning electron microscopy was used to investigate the microstructure of the materials. X-ray diffraction was able to confirm the formation of geopolymer. The mechanical properties of AMK material were nearly equivalent to those based on CMK. Neither CMK nor AMK reacted completely, although samples made with CMK showed less unreacted material. By increasing the mixing intensity and duration, the amount of residual unreacted material was substantially reduced, and mechanical properties were improved.


2013 ◽  
Vol 86 (2) ◽  
pp. 205-217 ◽  
Author(s):  
Hedayatollah Sadeghi Ghari ◽  
Zahra Shakouri

ABSTRACT Research was undertaken on natural rubber (NR) nanocomposites with organoclays. A double-network (DN) structure is formed when a partially cross-linked elastomer is further cross-linked during a state of strain. Two methods were used in the preparation of NR/organoclay nanocomposites: the ordinary method (single-network NR nanocomposite) and double-networked NR (DN-NR) nanocomposites. The single-networked NR nanocomposites were used for comparison. The effects of organoclay (5 phr) with a different extension ratio on curing characteristics, mechanical properties, hardness, swelling behavior, and morphology of single- and double-networked NR nanocomposites were studied. The results showed that double-networked NR nanocomposites exhibited higher physical and mechanical properties. The tensile strength of DN-NR nanocomposites increased up to 33 MPa (more than four times greater than that of pure NR) and then decreased with an increasing extension ratio. Modulus and hardness continuously increased with an increased extension ratio. The microstructure of the NR/organoclay systems was studied by X-ray diffraction and field emission scanning electron microscopy. The effects of different extension ratios on the dispersion of organoclay layers in the nanocomposites were investigated. Generally, results showed that the optimized extension ratio in DN nanocomposites was equal (or about or around) to α= 2.


2014 ◽  
Vol 50 (1) ◽  
pp. 87-90 ◽  
Author(s):  
E. Aldirmaz ◽  
I. Aksoy

In this study, some physical and mechanical properties in Cu-9.97%Al-4.62%Mn (wt%) alloy were investigated by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and compression deformation test. Bainite phase were obtained in the samples according to SEM and XRD analyses. Compression stress was applied on the alloy in order to investigate the deformation effect on the bainite phase transformation. On the surface of the Cu-9.97%Al-4.62%Mn alloy after the deformation, both bainite and martensite variants formed.


Author(s):  
Mohammad K. Hossain ◽  
Samira N. Shaily ◽  
Hadiya J. Harrigan ◽  
Terrie Mickens

A completely biodegradable composite was fabricated from an herbal polymer, soy protein concentrate (SPC) resin. Soy protein was modified by adding 30 wt% of glycerol and 5 wt% of poly vinyl alcohol (PVA) to enhance its mechanical as well as thermal property. 3%, 5%, 10%, and 20% nanoclay (NC) were infused into the system. To evaluate its mechanical properties, crystallinity, thermal properties, bonding interaction, and morphological evaluation, tensile, X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR) tests, and optical microscopy (OM) and scanning electron microscopy (SEM) evaluation were performed. Tensile tests showed that the addition of nanoclay improved the mechanical properties of the modified resin. Soy protein is hydrophilic due to the presence of amino acids that contain various polar groups such as amine, carboxyl, and hydroxyl. As a result, polar nanoclay particles that are exfoliated can be evenly dispersed in the SPC resin. From experimental results, it is clear that adding of nanoclay with SPC resin significantly increased the stiffness of the SPC resin. A combination of 5% clay, 30% glycerol, and 5% PVA with the modified SPC resulted in the maximum stress of 18 MPa and Young modulus of 958 MPa. The modified SPC showed a reduced failure strain as well. X-ray diffraction curves showed an improvement of crystallinity of the prepared resin with increasing amount of nanoclay. Interaction among soy, glycerol, PVA, and nanoclay was clearly demonstrated from the FTIR analysis. Optical microscopy (OM) and scanning electron microscopy (SEM) micrographs revealed rougher surface in the nanoclay infused SPC samples compared to that of the neat one. SEM evaluation revealed rougher fracture surface in the NC infused samples.


2012 ◽  
Vol 05 ◽  
pp. 551-558 ◽  
Author(s):  
A. RAHIMNEZHAD YAZDI ◽  
H.R. BAHARVANDI ◽  
H. ABDIZADEH ◽  
N. EHSANI

In this study Al 2 O 3- SiC nanocomposites have been fabricated by mixing of alumina and silicon carbide nano powders, followed by hot pressing at 1700°C. The mechanical properties and fracture mode of Al 2 O 3- SiC nanocomposites containing different volume fractions (5, 10 and 15%) of nano scale SiC particles were investigated and compared with those of alumina. Al 2 O 3- SiC powders were prepared by planetary milling in isopropanol. Fracture mode of specimens was investigated by means of scanning electron microscopy. Nanocomposites were tougher than alumina when they were hot pressed at the same temperature, and the values of nanocomposite's flexural strength and hardness were higher than those of alumina. Flexural strength, hardness and fracture toughness of the nanocomposites increase by increasing the volume percent of SiC up to 10% and then decrease slightly. The Scanning electron microscopy observations showed that fracture mode changes from intergranular for alumina to transgranular for nanocomposites. Finally X-ray diffraction analysis couldn't detect any chemical reactions between Al 2 O 3 and SiC particles.


2019 ◽  
Vol 821 ◽  
pp. 201-205
Author(s):  
Chao Deng ◽  
Xian Gyu Jin

In this work, pulp/lyocell wet-laid paper sheets have been consolidated by hydroentanglement techniques. Scanning electron microscopy has been used to evaluate the structures of wet-laid paper sheets before and after hydroentanglement. Wet tensile strength along longitudinal (preferential) and transverse directions show the effect of hydroentanglement techniques on the mechanical properties of wet-laid paper sheets. In addition, the air permeability and water absorbency properties of materials have been evaluated. The results show that the structures of wet-laid paper sheets become fluffy and fiber entanglements increase after consolidation. The wet tensile strength values of wet-laid paper sheets at the longitudinal and transverse directions are increased by 109.0% and 78.7%, respectively after hydroentanglement. The air permeability and water absorbency of wet-laid paper sheets are increased by 957.6% and 137.0%.


2015 ◽  
Vol 817 ◽  
pp. 192-197
Author(s):  
Xin Zhang ◽  
Ze Hua Wang ◽  
Ze Hua Zhou ◽  
Jian Ming Xu ◽  
Zhao Jun Zhong ◽  
...  

A series of Al-3.2Mg alloys with addition of 0~1.6 wt.% rare earth (Ce and La) were prepared. The microstructure of as-cast Al-3.2Mg alloys was investigated by optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and the tensile strength was measured. The results indicated that the addition of rare earth elements refined grain size and secondary dendrite arm spacing (SDAS), and the tensile strength was affected by means of the second-phase precipitation and the grain boundary. Accordingly, the ductility of Al-3.2Mg alloys reduced with the increasing of RE addition due to the more second-phase formation.


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