Influence of nonuniform network on mechanical properties of nano-silica reinforced silicone rubber

2016 ◽  
Vol 49 (4) ◽  
pp. 332-344 ◽  
Author(s):  
Wanjuan Chen ◽  
Xingrong Zeng ◽  
Hongqiang Li ◽  
Xuejun Lai ◽  
Weizhen Fang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Process Analysis ◽  
Mechanical Analysis ◽  
Nano Silica ◽  
Electron Microscopic ◽  
Stick Slip ◽  
Network Characteristics ◽  
Scanning Electron Microscopic ◽  
Silicone Rubbers ◽  
Base Network

Nonuniform networks were introduced into the nano-silica reinforced silicone rubbers, by co-cross-linking of silicone gum containing 0.05 mol% vinyl ( GL) and gum containing 3 mol% vinyl ( GH), so as to improve the mechanical properties. Their network characteristics were investigated by nuclear magnetic resonance measurement, swelling experiment, dynamic mechanical analysis, and rubber process analysis. Nonuniform networks displayed high tear strengths up to 41 kN m−1 and improved tensile strengths and elongations at break. Nonuniform networks with 7–10 phr of GH had optimal mechanical properties, since densely cross-linked domains scattered in base network and imparted maximum heterogeneity. In this structure, dense domains favored high modulus, while dominated long chains contributed to large extensibility. Hence, such structure could display large elongation before fracture while showing twice modulus upturns and stick-slip tearing characteristics, which were demonstrated by Mooney–Rivlin curves, tearing curves, and scanning electron microscopic images.

scholarly journals Preparation of Reswellable Amorphous Porous Celluloses through Hydrogelation from Ionic Liquid Solutions

Materials ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3249 ◽  
Author(s):  
Satoshi Idenoue ◽  
Yoshitaka Oga ◽  
Daichi Hashimoto ◽  
Kazuya Yamamoto ◽  
Jun-ichi Kadokawa
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
X Ray ◽  
Liquid Solutions ◽  
Scanning Electron Microscopic ◽  
Porous Morphology ◽  
Scanning Electron

In this study, we have performed the preparation of reswellable amorphous porous celluloses through regeneration from hydrogels. The cellulose hydrogels were first prepared from solutions with an ionic liquid, 1-butyl-3-methylimidazolium chloride (BMIMCl), in different concentrations. Lyophilization of the hydrogels efficiently produced the regenerated celluloses. The powder X-ray diffraction and scanning electron microscopic measurements of the products suggest an amorphous structure and porous morphology, respectively. Furthermore, the pore sizes of the regenerated celluloses, or in turn, the network sizes of cellulose chains in the hydrogels, were dependent on the concentrations of the initially prepared solutions with BMIMCl, which also affected the tensile mechanical properties. It was suggested that the dissolution states of the cellulose chains in the solutions were different, in accordance with the concentrations, which representatively dominated the pore and network sizes of the above materials. When the porous celluloses were immersed in water, reswelling was observed to regenerate the hydrogels.

scholarly journals Mechanical and Morphological Properties of Polypropylene/Nanoα-Al2O3Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
F. Mirjalili ◽  
L. Chuah ◽  
E. Salahi
Keyword(s):  
Mechanical Properties ◽  
Flexural Modulus ◽  
Mechanical Tests ◽  
Filler Loading ◽  
Morphological Properties ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Flexural Analysis ◽  
Flexural Tests ◽  
Internal Mixer

A nanocomposite containing polypropylene (PP) and nanoα-Al2O3particles was prepared using a Haake internal mixer. Mechanical tests, such as tensile and flexural tests, showed that mechanical properties of the composite were enhanced by addition of nanoα-Al2O3particles and dispersant agent to the polymer. Tensile strength was approximately∼16% higher than pure PP by increasing the nanoα-Al2O3loading from 1 to 4 wt% into the PP matrix. The results of flexural analysis indicated that the maximum values of flexural strength and flexural modulus for nanocomposite without dispersant were 50.5 and 1954 MPa and for nanocomposite with dispersant were 55.88 MPa and 2818 MPa, respectively. However, higher concentration of nanoα-Al2O3loading resulted in reduction of those mechanical properties that could be due to agglomeration of nanoα-Al2O3particles. Transmission and scanning electron microscopic observations of the nanocomposites also showed that fracture surface became rougher by increasing the content of filler loading from 1 to 4% wt.

Rheological, mechanical, thermal and barrier properties of highly elastic polyurethane/zinc ionomer composite films

2020 ◽  
pp. 089270572093917
Author(s):  
Balasubramanian Rukmanikrishnan ◽  
Juwon Chae ◽  
Jaewoong Lee
Keyword(s):  
Composite Films ◽  
Barrier Properties ◽  
Mechanical Analysis ◽  
Major Effect ◽  
High Ratio ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Elongation At Break ◽  
Scanning Electron Microscopic ◽  
Extrusion Method

Polyurethane (PU) and zinc ionomer (ZnI)-based polymer composites films were developed by melt extrusion method. The structure, phase morphology, rheology, and mechanical properties of the PU/ZnI blends were studied. The X-ray diffraction analysis displaced that there is no major effect on the crystallinity of PU phase by the addition of ZnI. Scanning electron microscopic images confirmed the partial miscibility of PU and ZnI, which greatly influenced on the tensile and elongation at break (EB) properties of the composite films at a high ratio. Dynamic mechanical analysis indicated that with increasing the ZnI content, the storage modulus of the blends decreased and exhibited two T g temperature peaks. Tensile strength of the PU/ZnI composites decreased drastically and EB increased significantly by the addition of ZnI, however a degree of interaction has been found. PU/ZnI composite films improved surface hydrophobic with excellent water barrier properties. The ultraviolet transmittance of the PU increased with increasing the content of ZnI.

Influence of constituents and process parameters on mechanical properties of flax fibre-reinforced polyamide 11 composite

2016 ◽  
Vol 30 (11) ◽  
pp. 1503-1521 ◽  
Author(s):  
Yann Lebaupin ◽  
Michaël Chauvin ◽  
Thuy-Quynh Truong Hoang ◽  
Fabienne Touchard ◽  
Alexandre Beigbeder
Keyword(s):  
Process Parameters ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Damping Factor ◽  
Hot Press ◽  
Scanning Calorimetry ◽  
Electron Microscopic ◽  
Polyamide 11 ◽  
Optimum Configuration ◽  
Scanning Electron Microscopic

Flax unidirectional (UD) fabrics and polyamide 11 (PA11) are used to create a 100% bio-sourced composite. The fabrication process is hot press moulding. Different configurations are studied by varying process parameters and composite constituents. Three temperature values (190°C, 200°C and 210°C) are combined with three pressure levels (35, 65 and 100 bars). In addition, two types of flax fabric (A and B) are tested and two types of PA11 (in the form of powder or film) are used. The two forms of PA11 are characterized using differential scanning calorimetry and rheological methods. Ten different composites are then manufactured. They are compared by means of tensile tests and dynamic mechanical analysis (DMA). Results are correlated with microstructural study: measurements of porosity degree and scanning electron microscopic observations are also performed. Finally, an optimum configuration is determined: the composite flax B/PA11 film manufactured with a temperature value of 210°C and using gradual levels of pressure (25 bars during 2 min, 40 bars during 2 min and 65 bars until the end of cycle). This configuration leads to a Young’s modulus value of 36 GPa and a tensile strength of 174 MPa, with the highest storage modulus and the lowest damping factor values measured by DMA.

Study on the Experimental Ratio of New Cement-Based Composite Insulation Board

2013 ◽  
Vol 468 ◽  
pp. 32-35
Author(s):  
Xiao Long Li ◽  
Guo Zhong Li
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Raw Material ◽  
Optimal Dosage ◽  
Action Mechanism ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Experimental Ratio ◽  
Scanning Electron

In the experiment, polystyrene particles, cement, fly ash, activator and fibers were used as raw material to prepare new cement-based composite insulation board by compression molding. Through the determination of best content of fly ash, the effects of fly ash on strength of composite insulation board were studied. Through the determination of the optimal content of activators, the effects of activators on the mechanical properties of composite insulation board were studied. Through the determination of the optimal dosage of fibers, the effects of fibers on performance of composite insulation board were studied. The morphology in the samples was observed by scanning electron microscopic, and the action mechanism of each component was studied.

Effect of polyurethane dispersion treatment on the performance improvement of carbon woven fabric-reinforced composites

2017 ◽  
Vol 31 (3) ◽  
pp. 408-425 ◽  
Author(s):  
Yuqiu Yang ◽  
Zhiyuan Zhang ◽  
Yan Ma ◽  
Masahito Ueda ◽  
Tomohiro Yokozeki ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surface Treatment ◽  
Mechanical Analysis ◽  
Interfacial Interaction ◽  
Woven Fabric ◽  
Thermoplastic Composites ◽  
Electron Microscopic ◽  
Polyurethane Dispersion ◽  
Static Tensile ◽  
Initial Fracture

In this study, two types of polyurethane dispersion were applied as surface treatment for 10 types of washed/nonwashed carbon plain woven fabric-reinforced thermosetting and thermoplastic composites. To investigate the effects of surface treatment on the mechanical properties, the impregnation of various laminates was observed by a digital microscope. Dynamic mechanical analysis (DMA) was employed to investigate the interfacial interaction properties. Static tensile test was used to study the mechanical properties of composites. A correlation between the mechanical properties and interfacial interaction of composites was successfully observed. The acoustic emission (AE) from various composites was recorded in order to investigate the initial fracture and failure mechanism. Meanwhile, the knee-point method was also employed to look for initial fracture, which showed a good fit to initial strain detected from AE (amplitude > 80 dB). Furthermore, scanning electron microscopic images of single fiber and fractured carbon fiber bundles confirmed the interfacial properties evaluated by DMA analysis. Finally, remarkable improvement in mechanical properties (≈33.3%) of CF/PA6 laminates is discussed.

scholarly journals Dichlorobenzene: an effective solvent for epoxy/graphene nanocomposites preparation

2017 ◽  
Vol 4 (10) ◽  
pp. 170778 ◽  
Author(s):  
Jiacheng Wei ◽  
Mohd Shahneel Saharudin ◽  
Thuc Vo ◽  
Fawad Inam
Keyword(s):  
Colloidal Stability ◽  
Mechanical Analysis ◽  
Electron Microscopic ◽  
Graphene Nanocomposites ◽  
Dispersion Component ◽  
Graphene Dispersion ◽  
Scanning Electron Microscopic ◽  
Hildebrand Solubility Parameter ◽  
First Time ◽  
Scanning Electron

It is generally recognized that dimethylformamide (DMF) and ethanol are good media to uniformly disperse graphene, and therefore have been used widely in the preparation of epoxy/graphene nanocomposites. However, as a solvent to disperse graphene, dichlorobenzene (DCB) has not been fully realized by the polymer community. Owing to high values of the dispersion component ( δ d ) of the Hildebrand solubility parameter, DCB is considered as a suitable solvent for homogeneous graphene dispersion. Therefore, epoxy/graphene nanocomposites have been prepared for the first time with DCB as a dispersant; DMF and ethanol have been chosen as the reference. The colloidal stability, mechanical properties, thermogravimetric analysis, dynamic mechanical analysis and scanning electron microscopic images of nanocomposites have been obtained. The results show that with the use of DCB, the tensile strength of graphene has been improved from 64.46 to 69.32 MPa, and its flexural strength has been increased from 97.17 to 104.77 MPa. DCB is found to be more effective than DMF and ethanol for making stable and homogeneous graphene dispersion and composites.

scholarly journals Effects of Boron and Carbon Added Titanium Filler on Microstructure and Mechanical Properties of Ti-15-3 Alloy Weldments

2019 ◽  
Vol 7 (4.14) ◽  
pp. 538
Author(s):  
Izzul Adli Bin Mohd Arif ◽  
Mahesh Kumar Talari ◽  
N Kishore Babu ◽  
Ahmad Lutfi Bin Anis ◽  
Muhammad Hussain Ismail ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Refinement ◽  
Microscopic Analysis ◽  
X Ray Diffraction ◽  
Electron Microscopic ◽  
Gas Tungsten Arc ◽  
Beta Titanium ◽  
Scanning Electron Microscopic ◽  
Scanning Electron Microscopic Analysis

Microstructural and mechanical properties beta Titanium (β-Ti) weldments can be improved by grain refinement and formation of insoluble precipitates in the weld. This paper reports the effect of Boron (B) and Carbon (C) addition to Ti-15V-3Cr-3Sn-3Al (Ti-15-3) fillers on the microstructural and mechanical properties of Ti-15-3 gas tungsten arc weldments. X-ray diffraction and scanning electron microscopic analysis revealed the presence of β-Ti phase in the weldments prepared without the filler modification, while additional TiB and TiC phases are observed in the weldments prepared with fillers modified with B and C, respectively. B and C addition to the fillers has resulted in the grain refinement of the weldments and the grain size reduction is seen to be higher with the increasing B and C addition. The formation of TiB, TiC and growth restriction effect due to the presence of B and C in the filler resulted in the decreased grain size of the β-Ti weldments. Mechanical properties such as hardness and tensile strength improved as the amount of B and C addition increased. The improvement of mechanical properties is contributed by the grain refinement and the formation of TiB and TiC precipitates in weldments. 

Preparation and Properties of Straw Fiber/Polylactic Acid Composites

2021 ◽  
Vol 1036 ◽  
pp. 122-129
Author(s):  
Kang Chen ◽  
Xian Jun Li ◽  
Yi Qiang Wu ◽  
Ying Feng Zuo
Keyword(s):  
Crystal Structure ◽  
Mechanical Properties ◽  
Polylactic Acid ◽  
Water Resistance ◽  
Differential Scanning Calorimetric ◽  
Mass Ratio ◽  
Electron Microscopic ◽  
X Ray ◽  
Scanning Electron Microscopic ◽  
Scanning Electron

Straw fiber (SF)/polylactic acid (PLA) composites were prepared from SF and PLA. The effects of the composite SF/PLA mass ratio investigated in terms of mechanical properties, water resistance, crystal structure, and thermal properties were investigated. These composites were characterized by scanning electron microscopic (SEM), X-ray diffractometric (XRD), differential scanning calorimetric (DSC), and thermogravimetric analyses (TGA). The results showed that, when the SF/PLA mass ratio was 3/7, the mechanical properties and water resistance of these composites were the best. When the mass ratio exceeded 3/7, the interface compatibility in the composites decreased. As the SF/PLA mass ratio increased, the crystallinity and the heat resistance of the composites were decreased.

Sign in / Sign up

Export Citation Format

Share Document