Characterization of the Mechanical Properties of Electrorheological Fluids Made of Starch and Silicone Fluid

1999 ◽  
Vol 13 (14n16) ◽  
pp. 1908-1916 ◽  
Author(s):  
Sheila Lopes Vieira ◽  
Antonio Celso Fonseca de Arruda

In the majority of published articles on the topic, ER fluids have been studied as if they were viscous liquids. In this work, electrorheological fluids were characterized as solids and their mechanical properties were determined. The results infer that ER materials are controllably resistant to compression, tensile and shear stress, in this order of magnitude. More precisely, fluids made of starch have elasticity modulus similar to that of rubber, they have tensile strength 103 to 5×104 times lower than that of low density polyethylene (LDPE), static yield stress 4×104 to 8×105 times lower than that of acrylonitrile-butadiene-styrene terpolymer (ABS) and fatigue life similar to some polymers like polyethylene(PE) and polypropylene (PP).

2021 ◽  
Vol 21 (9) ◽  
pp. 4840-4845
Author(s):  
Guixin Zhang ◽  
Yanyan Zhang ◽  
Jun Yang ◽  
Shijuan Li ◽  
Weihong Guo

The new wood-plastic nanocomposites (WPC) based on acrylonitrile-butadiene-styrene (ABS) resin was successfully blended with ABS and poplar flour (PF) through a HAAKE rheomix. The mechanical properties of nanocomposites, except for flexural modulus, were reduced after increasing the PF content. SEM photos show the reduction resulting from weak interfacial adhesion between the PF phase and ABS phase. Higher PF content leads to a low thermal stability and a high water absorption ratio. Different coupling agents (CA) were employed to improve the compatibility between PF and ABS. The results suggest that ABS-g-MAH is more effective than POE-g-MAH, EVA and SEBS. Maleic anhydride (MA) was blended in situ with PF and ABS as the reactive compatibilizer and mechanical properties of nanocomposites were improved except impact strength.


1998 ◽  
Vol 13 (10) ◽  
pp. 2783-2786 ◽  
Author(s):  
Weijia Wen ◽  
Wing Yim Tam ◽  
Ping Sheng

We report very large enhancement of static yield stress for electrorheological fluids by adding ferroelectric nanoparticles of lead zirconate titanate (PZT) or lead titanate (PbTiO3) to ER fluids consisting of 50 μm glass spheres. It is found that the enhancement peaks at certain nanoparticle/microparticle ratios for fixed solid/liquid volume fractions. The results are explained by calculations using an effective medium approach, based on the physical picture that the nanoparticles modify the properties of the liquid and solid components.


1999 ◽  
Vol 13 (14n16) ◽  
pp. 1931-1939 ◽  
Author(s):  
J. Akhavan ◽  
K. Slack ◽  
V. Wise ◽  
H. Block

Currents drawn under high fields often present practical limitations to electrorheological (ER) fluids usefulness. For heavy-duty applications where large torques have to be transmitted, the power consumption of a ER fluid can be considerable, and for such uses a current density of ~100μ A cm -2 is often taken as a practical upper limit. This investigation was conducted into designing a fluid which has little extraneous conductance and therefore would demand less current. Selected semi-conducting polymers provide effective substrates for ER fluids. Such polymers are soft insoluble powdery materials with densities similar to dispersing agents used in ER formulations. Polyaniline is a semi-conducting polymer and can be used as an effective ER substrate in its emeraldine base form. In order to provide an effective ER fluid which requires less current polyaniline was coated with an insulating polymer. The conditions for coating was established for lauryl and methyl methacrylate. Results from static yield measurements indicate that ER fluids containing coated polyaniline required less current than uncoated polyaniline i.e. 0.5μ A cm -2. The generic type of coating was also found to be important.


Author(s):  
Dominic Thaler ◽  
Nahal Aliheidari ◽  
Amir Ameli

Additive manufacturing is an emerging method to produce customized parts with functional materials without big investments. As one of the common additive manufacturing methods, fused deposition modeling (FDM) uses thermoplastic-based feedstock. It has been recently adapted to fabricate composite materials too. Acrylonitrile butadiene styrene (ABS) is the most widely used material as FDM feedstock. However, it is an electrically insulating polymer. Carbon Nanotubes (CNTs) on the other hand are highly conductive. They are attractive fillers because of their high aspect ratio, and excellent mechanical and physical properties. Therefore, a nanocomposite of these two materials can give an electrically conductive material that is potentially compatible with FDM printing. This work focuses on the investigation of the relationships between the FDM process parameters and the electrical conductivity of the printed ABS/CNT nanocomposites. Nanocomposite filaments with CNT contents up to 10wt% were produced using a twin-screw extruder followed by 3D printing using FDM method. The starting material was pellets from a masterbatch containing 15 wt% CNT. Compression-molded samples of ABS/CNT were also prepared as the bulk baselines. The effects of CNT content and nozzle size on the through-layer and in-layer electrical conductivity of the printed nanocomposites were analyzed. Overall, a higher percolation threshold was observed in the printed samples, compared to that of the compression-molded counterparts. This resulted in the conductivity of the printed samples that is at least one order of magnitude lower. Moreover, at CNT contents up to 5 wt%, the in-layer conductivity of the printed samples was almost two orders of magnitudes higher than that in the through-layer direction. In ABS/3 wt% CNT samples, the through-layer conductivity continuously decreased as the nozzle diameter was decreased from 0.8 mm to 0.35 mm. These variations in the electrical conductivity were explained in terms of the CNT alignment, caused by the extrusion process during the print, quality of interlayer bonding during deposition, and the voids created due to the discrete nature of the printing process.


RSC Advances ◽  
2015 ◽  
Vol 5 (61) ◽  
pp. 49143-49152 ◽  
Author(s):  
Ningjing Wu ◽  
Zhaoxia Xiu

Silicone-microencapsulated aluminum hypophosphite (SiAHP) improved effectively the flame retardancy and significantly enhanced the notched impact strength of ABS/SiAHP composites.


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