Effective viscoelastic behavior of polymer composites with regular periodic microstructures

2021 ◽  
Vol 216 ◽  
pp. 167-181
Author(s):  
Tarkes Dora Pallicity ◽  
Thomas Böhlke
Keyword(s):  
Polymer Composites ◽  
Viscoelastic Behavior ◽  
Periodic Microstructures

Analysis of the Linearly Viscoelastic Behavior of Nanotube-Reinforced Polymer Composites

2004 ◽  
Author(s):  
K. Li ◽  
X.-L. Gao ◽  
A. K. Roy
Keyword(s):  
Polymer Composites ◽  
Small Volume ◽  
Physical Aging ◽  
Volume Fraction ◽  
Viscoelastic Behavior ◽  
Analytical Models ◽  
Limited Attention ◽  
Creep Stress ◽  
Reinforced Polymer ◽  
Small Volume Fraction

In the last few years a lot of efforts have been made to demonstrate that the addition of carbon nanotubes, even with a small volume fraction, can substantially enhance the stiffness and strength of polymers [1]. Nevertheless, very limited attention has been paid to the viscoelastic responses of nanotube-reinforced polymer composites. Several groups have investigated the changes in glass transition temperatures of polymers induced by adding nanotubes to polymers [2–4]. Fisher [4] also studied the frequency response and the physical aging of polymers with or without nanotubes. However, the creep/stress relaxation behavior of nanotube-reinforced polymer composites is still not well understood. Experimental characterization tends to be configuration specific and expensive. Therefore, there is a need to develop analytical models that can predict the said behavior. The objective of this communication is to present a study on the creep behavior of carbon nanotube-reinforced polymer composites using a continuum-based micromechanics model.

The DMA, TG/DTA and FT-IR Characteristics of Wood Polymer Composites

2012 ◽  
Vol 445 ◽  
pp. 219-224 ◽  
Author(s):  
Ahmet Koyun ◽  
Esma Ahlatcioglu ◽  
Duygu Ceylan Erdogan ◽  
Yeliz Koca Ipek
Keyword(s):  
Mechanical Strength ◽  
Polymer Composites ◽  
Viscoelastic Behavior ◽  
Wood Chips ◽  
Wood Polymer ◽  
Content Preparation ◽  
Ft Ir ◽  
Long Term Behavior ◽  
The Relationship

Wood chips and polymer composites are effectively used in the industrial products. It is important to establish a relationship between mechanical strength and processability in extruder of these composites. Especially, the most important factor is to determine the time-dependent strength. Although many short-term values were obtained via normal mechanical experiments, very little effort has been spent in order to estimate the long-term behavior of polymer. Composites were prepared with processed and unprocessed wood chips. Pretreatment of wood chips were carried out by using hydrochloric acid (HCl) and water. The products were prepared with different ratios of mixtures which contain wood chips and high density polyethylene (HDPE) grains. The long-term mechanical behavior and viscoelastic behavior of these composites were analyzed using Dynamic Mechanic Analyzer (DMA) test equipment. The effect of composite content and pretreatment method of wood chips on mechanical strength of wood plastic composites (WPCs) were determined. The relationship among the composite content, preparation method of wood chips, DMA and TG/DTA test results were tried to establish. FT-IR spectrums of the beginning materials and the composites are also examined in order to determine the chemical bonds of these materials.

On Viscoelasticity in CNT-Reinforced Polymer Composites

2010 ◽  
Author(s):  
K. Yazdchi ◽  
M. Salehi
Keyword(s):  
Polymer Composites ◽  
Volume Fraction ◽  
Viscoelastic Behavior ◽  
Limited Attention ◽  
Viscoelastic Problem ◽  
Neat Polymer ◽  
Reinforced Polymer ◽  
Equivalent Inclusion ◽  
Linear Viscoelastic Behavior ◽  
Linear Viscoelastic

The nanocomposites exhibit high electrical conductivity, significant non-linear optical behavior and electroluminescence, while having substantially improved mechanical properties relative to the neat polymer. However, very limited attention has been paid to the viscoelastic behavior of nanotube reinforced polymer composites (NTRPCs). In this paper, the constitutive relation and linear viscoelastic behavior of NTRPC are studied using methods of micromechanics and nanomechanics. First, the effects of volume fraction, aspect ratio and orientation of carbon nanotubes (CNTs), on the overall elastic properties of NTRPC are obtained through a micromechanical technique based on Eshelby’s Equivalent Inclusion (EEI) and Mori-Tanaka (MT) method. Secondly, by incorporating the Dynamic Correspondence Principle (DCP), the elastic solution is extended to solve the related linear viscoelastic problem. The results of this study are in good agreement when compared with previous analytical and experimental data.

scholarly journals Effect of Wood Fillers on the Viscoelastic and Thermophysical Properties of HDPE-Wood Composite

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
M. Tazi ◽  
M. S. Sukiman ◽  
F. Erchiqui ◽  
A. Imad ◽  
T. Kanit
Keyword(s):  
Polymer Composites ◽  
Thermophysical Properties ◽  
High Density Polyethylene ◽  
Viscoelastic Behavior ◽  
Wood Composite ◽  
Materials Behaviors ◽  
Wood Polymer ◽  
Wood Particles ◽  
Wood Polymer Composites

Wood polymer composites (WPC) have well proven their applicability in several fields of the plasturgy sector, due to their aesthetics and low maintenance costs. However, for plasturgy applications, the characterization of viscoelastic behavior and thermomechanical and thermophysical properties of WPC with the temperature and wood filler contents is essential. Therefore, the processability of polymer composites made up with different percentage of wood particles needs a better understanding of materials behaviors in accordance with temperature and wood particles contents. To this end, a numerical analysis of the viscoelastic, mechanical, and thermophysical properties of composite composed of high density polyethylene (HDPE) reinforced with soft wood particles is evaluated.

On resolving fine periodic microstructures in the optical microscope

1989 ◽  
Vol 47 ◽  
pp. 364-365
Author(s):  
W.S. Putnam ◽  
C. Viney
Keyword(s):  
Liquid Crystalline ◽  
Numerical Aperture ◽  
Polarized Light ◽  
Normal Incidence ◽  
Optical Microscope ◽  
Angle Of Incidence ◽  
Resolution Limit ◽  
Crystalline Materials ◽  
Periodic Microstructures ◽  
Liquid Crystalline Materials

Many sheared liquid crystalline materials (fibers, films and moldings) exhibit a fine banded microstructure when observed in the polarized light microscope. In some cases, for example Kevlar® fiber, the periodicity is close to the resolution limit of even the highest numerical aperture objectives. The periodic microstructure reflects a non-uniform alignment of the constituent molecules, and consequently is an indication that the mechanical properties will be less than optimal. Thus it is necessary to obtain quality micrographs for characterization, which in turn requires that fine detail should contribute significantly to image formation.It is textbook knowledge that the resolution achievable with a given microscope objective (numerical aperture NA) and a given wavelength of light (λ) increases as the angle of incidence of light at the specimen surface is increased. Stated in terms of the Abbe resolution criterion, resolution improves from λ/NA to λ/2NA with increasing departure from normal incidence.

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