Dynamic Mechanical Analysis of Fly Ash Filled Polyurea Elastomer

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Jing Qiao ◽  
Alireza V. Amirkhizi ◽  
Kristin Schaaf ◽  
Sia Nemat-Nasser
Keyword(s):  
Glass Transition ◽  
Fly Ash ◽  
Dynamic Mechanical Analysis ◽  
Volume Fraction ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Temperature Dependent ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Temperature Superposition

In this work, the material properties of a series of fly ash/polyurea composites were studied. Dynamic mechanical analysis was conducted to study the effect of the fly ash volume fraction on the composite’s mechanical properties, i.e., on the material’s frequency- and temperature-dependent storage and loss moduli. It was found that the storage and loss moduli of the composite both increase as the fly ash volume fraction is increased. The storage and loss moduli of the composites relative to those of pure polyurea initially increase significantly with temperature and then slightly decrease or stay flat, attaining peak values around the glass transition region. The glass transition temperature (measured as the temperature at the maximum value of the loss modulus) shifted toward higher temperatures as the fly ash volume fraction increased. Additionally, we present the storage and loss moduli master curves for these materials obtained through application of the time-temperature superposition on measurements taken at a series of temperatures.

scholarly journals Dynamic Mechanical Analysis as a Complementary Technique for Stickiness Determination in Model Whey Protein Powders

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1295
Author(s):  
Laura O’Donoghue ◽  
Md. Haque ◽  
Sean Hogan ◽  
Fathima Laffir ◽  
James O’Mahony ◽  
...  
Keyword(s):  
Glass Transition ◽  
Dynamic Mechanical Analysis ◽  
Whey Protein ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Whey Protein Concentrate ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Lower Protein

The α-relaxation temperatures (Tα), derived from the storage and loss moduli using dynamic mechanical analysis (DMA), were compared to methods for stickiness and glass transition determination for a selection of model whey protein concentrate (WPC) powders with varying protein contents. Glass transition temperatures (Tg) were determined using differential scanning calorimetry (DSC), and stickiness behavior was characterized using a fluidization technique. For the lower protein powders (WPC 20 and 35), the mechanical Tα determined from the storage modulus of the DMA (Tα onset) were in good agreement with the fluidization results, whereas for higher protein powders (WPC 50 and 65), the fluidization results compared better to the loss modulus results of the DMA (Tα peak). This study demonstrates that DMA has the potential to be a useful technique to complement stickiness characterization of dairy powders by providing an increased understanding of the mechanisms of stickiness.

Viscoelastic Properties Assessment of Syntactic Foams by Dynamic Mechanical Analysis

2010 ◽  
Vol 636-637 ◽  
pp. 280-286 ◽  
Author(s):  
Carlos Capela ◽  
José A. Martins Ferreira ◽  
José Domingos M. Costa
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Glass Fibre ◽  
Volume Fraction ◽  
Mechanical Analysis ◽  
Fibre Reinforcement ◽  
Dynamic Mechanical ◽  
Filler Volume Fraction

Low-density sheet moulding compounds incorporating hollow glass micro-spheres are being increasing used namely in automotive industry, boats and deep-water submarines and core materials. This paper presents the results obtained in a current study of the viscous properties on hybrid short fibre/hollow glass microspheres composites fabricated with epoxy binder. Dynamic mechanical analysis (DMA) was used to study the effect of the filler volume fraction and of the addition of glass fibre reinforcement on the dynamic stiffness modulus, damping coefficient and glass transition temperature in tensile mode. The specimens were cut from plates produced by resin transfer moulding in vacuum with microspheres weight contents up to 13%. Elastic modulus decreases significantly with the increasing of filler volume fraction. In contrary, it increases significantly with the glass fibre reinforcement content. Glass transition temperature apparently tends to decrease with microspheres and of glass fibre reinforcement’s content. Tmax temperatures tend to increase slightly with the addition of fibre reinforcements and the microsphere filler. Maximum damping coefficient is much lower for the foams when compared with net resin.

A Comparative Study on Dynamic Mechanical Properties of Radial and Chordwise Direction of Bamboo

2013 ◽  
Vol 838-841 ◽  
pp. 2227-2230
Author(s):  
Chun Gui Du ◽  
Ren Li ◽  
Zhe Wang ◽  
Hong Wei Yu ◽  
Chun De Jin
Keyword(s):  
Mechanical Properties ◽  
Glass Transition ◽  
Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Radial Direction ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Dynamic Mechanical ◽  
Environment Temperature

The dynamic mechanical properties of radial and chordwise bamboo pieces were tested by dynamic mechanical analysis (DMA). The results show that the storage modulus and loss modulus and tangent delta of chordwise direction were all larger than the radial direction of bamboo; the peak of glass transition temperature of chordwise direction is high than the radial direction, and their sizes are very close; dynamic mechanical analysis can provide a reference for the optimization applicable environment temperature of curtain plybamboo.

Viscoelastic Deformation of PC/ABS Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 1229-1232
Author(s):  
Z.N. Yin ◽  
L.F. Fan ◽  
Tie Jun Wang
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Relaxation Modulus ◽  
Mechanical Analysis ◽  
Experimental Results ◽  
Viscoelastic Deformation ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Static Relaxation ◽  
Comparison Of The Results ◽  
Good Agreement

Dynamic Mechanical Analysis (DMA) and static relaxation tests are carried out to study the viscoelastic deformation of PC/ABS alloy with blending ratio of PC to ABS being 50/50. A modified approach is developed to calculate the relaxation modulus of PC/ABS alloy from the DMA experimental results of storage and loss moduli. Comparison of the results obtained from DMA and static relaxation tests is presented and good agreement is found.

scholarly journals Replacement of metallic parts for polymer composite materials in motorcycle oil pumps

2016 ◽  
Vol 36 (2) ◽  
pp. 149-160 ◽  
Author(s):  
Sandro Donnini Mancini ◽  
Antídio de Oliveira Santos Neto ◽  
Maria Odila Hilário Cioffi ◽  
Eduardo Carlos Bianchi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Glass Transition ◽  
Glass Fiber ◽  
Dynamic Mechanical Analysis ◽  
Mechanical Analysis ◽  
Neutral Medium ◽  
Element Analysis ◽  
Dynamic Mechanical ◽  
Oil Pump

A feasibility study was conducted to determine the use of polyphthalamide/glass-fiber and polyphthalamide/glass-fiber/polytetrafluoroethylene-based composites as substitutes for aluminum and steel, respectively, in the production of motorcycle oil pump parts (housing, shaft/inner gerotor and outer gerotor). New and used (80,000 km) oil pumps were subjected to performance tests, whose results indicated that the pressure and temperature of the used pump reached a maximum of 1.8 bar and 93℃, respectively. Thermogravimetric analysis indicated that the materials are stable at the maximum operating temperature, which is 20℃ lower than the minimum glass transition temperature obtained by dynamic mechanical analysis for both materials at the analyzed frequencies (defined after calculations based on rotations in neutral, medium and high gear). The pressure value was multiplied by a safety factor of at least 1.6 (i.e., 3 bar), which was used as input for a finite element analysis of the parts, as well as the elasticity modulus at glass transition temperatures obtained by dynamic mechanical analysis. The finite element analysis indicated that the von Mises stresses to which the composite parts were subjected are 7 to 50 times lower than those the materials can withstand. The results suggest that it is feasible to manufacture motorcycle oil pump parts with these composites.

Dynamic mechanical behaviour of kevlar and carbon-kevlar hybrid fibre reinforced polymer composites

2020 ◽  
pp. 095440622097060
Author(s):  
Pragati Priyanka ◽  
Harlal Singh Mali ◽  
Anurag Dixit
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Dynamic Mechanical Analysis ◽  
Storage Modulus ◽  
Composite Laminates ◽  
Mechanical Analysis ◽  
Textile Composites ◽  
Elastic Behaviour ◽  
Dynamic Mechanical

Comprehensive experimental results of dynamic mechanical analysis (DMA) of polymer reinforced textile composites are presented in the current investigation. Plain and 2x2 twill woven multilayer fabrics of monolithic kevlar and hybrid carbon-kevlar (C-K) are reinforced into the thermoset polymer matrix. Kevlar/epoxy and C-K/epoxy composite laminates are fabricated using an in-house facility of the vacuum-assisted resin infusion process. Variation of the visco-elastic behaviour (storage modulus, damping factor and glass transition temperature, Tg) along with time, temperature and frequency is studied for the composites. Dynamic mechanical analysis is performed under temperature sweep with frequency ranging from 1-50 Hz. Results depict the effect of inter yarn hybridisation of carbon with kevlar yarns on the storage modulus, damping performance, and creep behaviour of dry textile composites. Temperature swept dynamic characterisation is also performed to evaluate the degradation and damping performance of the composite laminates soaked in the deionised water at glass transition temperature Tg, ½ Tg, and ¾ Tg. The morphological study has been performed post the dynamic mechanical analysis using field emission scanning electron microscope.

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