scholarly journals Effect of Nanofiller Content on Dynamic Mechanical and Thermal Properties of Multi-Walled Carbon Nanotube and Montmorillonite Nanoclay Filler Hybrid Shape Memory Epoxy Composites

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 700
Author(s):  
Muhamad Hasfanizam Mat Yazik ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohammad Jawaid ◽  
Abd Rahim Abu Talib ◽  
Norkhairunnisa Mazlan ◽  
...  
Keyword(s):  
Shape Memory ◽  
High Performance ◽  
Loss Modulus ◽  
Decomposition Temperature ◽  
Hybrid Nanocomposites ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Tan Δ

The aim of the present study has been to evaluate the effect of hybridization of montmorillonite (MMT) and multi-walled carbon nanotubes (MWCNT) on the thermal and viscoelastic properties of shape memory epoxy polymer (SMEP) nanocomposites. In this study, ultra-sonication was utilized to disperse 1%, 3%, and 5% MMT in combination with 0.5%, 1%, and 1.5% MWCNT into the epoxy system. The fabricated SMEP hybrid nanocomposites were characterized via differential scanning calorimetry, dynamic mechanical analysis, and thermogravimetric analysis. The storage modulus (E’), loss modulus (E”), tan δ, decomposition temperature, and decomposition rate, varied upon the addition of the fillers. Tan δ indicated a reduction of glass transition temperature (Tg) for all the hybrid SMEP nanocomposites. 3% MMT/1% MWCNT displayed best overall performance compared to other hybrid filler concentrations and indicated a better mechanical property compared to neat SMEP. These findings open a way to develop novel high-performance composites for various potential applications, such as morphing structures and actuators, as well as biomedical devices.

Thermal and dynamic mechanical analysis of hybrid jute/sisal fibre reinforced epoxy composite

2016 ◽  
Vol 232 (9) ◽  
pp. 743-748 ◽  
Author(s):  
MK Gupta
Keyword(s):  
Thermal Properties ◽  
Storage Modulus ◽  
Hybrid Composites ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Decomposition Temperature ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Sisal Fibre ◽  
Dynamic Mechanical

The aim of the present study is to investigate the dynamic mechanical and thermal properties of hybrid jute/sisal fibre reinforced epoxy composites. The hybrid composites were prepared by hand layup technique having total fibre loading of 30% by weight with different weight ratios of jute and sisal fibres. Dynamic mechanical properties such as storage modulus ([Formula: see text]), loss modulus ([Formula: see text]) and damping ([Formula: see text]) were investigated in the temperature range of 30–200 ℃. The thermal stability of the prepared composites was studied using thermogravimetric analysis. Other thermal properties such as glass transition temperature ( Tg), crystallization temperature ( Tc) and decomposition temperature ( Td) were also obtained by differential scanning calorimetry. The results indicated a positive effect of hybridization in terms of increase in dynamic mechanical and thermal properties. Storage modulus, loss modulus and Tg were found to be higher for hybrid composite having a higher percentage of jute fibres.

scholarly journals The Effect of Bi-Functionalized MMT on Morphology, Thermal Stability, Dynamic Mechanical, and Tensile Properties of Epoxy/Organoclay Nanocomposites

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2012 ◽  
Author(s):  
Siew Sand Chee ◽  
Mohammad Jawaid
Keyword(s):  
Thermal Stability ◽  
Tensile Properties ◽  
In Situ Polymerization ◽  
Loss Modulus ◽  
Mechanical Analysis ◽  
Decomposition Temperature ◽  
Filler Loading ◽  
Hybrid Nanocomposites ◽  
Dynamic Mechanical ◽  
Link Density

In this work, the optimum filler loading to prepare epoxy/organoclay nanocomposites by the in-situ polymerization method was studied. Bi-functionalized montmorillonite at different filler loading (0.5, 1.0, 2.0, 4.0 wt %) was dispersed in epoxy resin by using a high shear speed homogenizer. The effect on morphology, thermal, dynamic mechanical, and tensile properties of the epoxy/organoclay nanocomposites were studied in this work. Wide-angle X-ray scattering (WAXS) and field emission scanning electron microscope (FESEM) studies revealed that possible intercalated structures were obtained in epoxy/organoclay nanocomposites. Thermogravimetric analysis (TGA) shows that epoxy/organoclay nanocomposites exhibit higher thermal stability at the maximum and final decomposition temperature, as well as higher char content, compared to pristine epoxy. The dynamic mechanical analysis (DMA) indicate that storage modulus (E′), loss modulus (E″), cross-link density and glass transition temperature (Tg) of the nanocomposites were improved with organoclay loading up to 1 wt %. Beyond this loading limit, the deterioration of properties was observed. A similar trend was also observed on tensile strength and modulus. We concluded from this study that organoclay loading up to 1 wt % is suitable for further study to fabricate hybrid nanocomposites for various applications.

scholarly journals Mechanically Robust Hybrid POSS Thermoplastic Polyurethanes with Enhanced Surface Hydrophobicity

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 373 ◽  
Author(s):  
Xiuhuan Song ◽  
Xiaoxiao Zhang ◽  
Tianduo Li ◽  
Zibiao Li ◽  
Hong Chi
Keyword(s):  
High Performance ◽  
Mechanical Performance ◽  
Loss Modulus ◽  
Surface Hydrophobicity ◽  
Hexamethylene Diisocyanate ◽  
Scanning Calorimetry ◽  
Hybrid Filler ◽  
Remarkable Effect ◽  
Thermoplastic Polyurethanes ◽  
Static Contact

A series of hybrid thermoplastic polyurethanes (PUs) were synthesized from bi-functional polyhedral oligomeric silsesquioxane (B-POSS) and polycaprolactone (PCL) using 1,6-hexamethylene diisocyanate (HDI) as a coupling agent for the first time. The newly synthesized hybrid materials were fully characterized in terms of structure, morphology, thermal and mechanical performance, as well as their toughening effect toward polyesters. Thermal gravimeter analysis (TGA) and differential scanning calorimetry (DSC) showed enhanced thermal stability by 76 °C higher in decomposition temperature (Td) of the POSS PUs, and 22 °C higher glass transition temperature (Tg) when compared with control PU without POSS. Static contact angle results showed a significant increment of 49.8° and 53.4° for the respective surface hydrophobicity and lipophilicity measurements. More importantly, both storage modulus (G’) and loss modulus (G’’) are improved in the hybrid POSS PUs and these parameters can be further adjusted by varying POSS content in the copolymer. As a biodegradable hybrid filler, the as-synthesized POSS PUs also demonstrated a remarkable effect in toughening commercial polyesters, indicating a simple yet useful strategy in developing high-performance polyester for advanced biomedical applications.

Dynamic Mechanical Analysis of Nanosilica Filled Epoxy Nanocomposites

2014 ◽  
Vol 699 ◽  
pp. 239-244 ◽  
Author(s):  
Nurhidayah R. Zamani ◽  
Aidah Jumahat ◽  
Rosnadiah Bahsan
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Epoxy Polymer ◽  
Loss Modulus ◽  
Matrix Material ◽  
Mechanical Analysis ◽  
Dynamic Mechanical ◽  
Mechanical Stirring ◽  
Tan Δ

In this study, Dynamic Mechanical Analyzer (DMA) was used to study the effect of nanoparticles, which is nanosilica, on glass transition temperature (Tg) of epoxy polymer. A series of epoxy based nanosilica composite with 5-25 wt% nanosilica content was prepared using mechanical stirring method. The weight fractions of nanosilica in epoxy were 5 wt%, 13 wt% and 25 wt%. 30mm x 10mm x 3mm size specimens were tested using DMA machine from room temperature up to 180oC at 2°C/min heating rate. From the analysis of the results, dynamic modulus and glass transition temperature of pure polymer and nanosilica filled polymer were obtained. The glass transition of a polymer composite is a temperature-induced change in the matrix material from the glassy to the rubbery state during heating or cooling. Glass transition temperature Tg was determined using several method: storage modulus onset, loss modulus peak, and tan δ peak. The results showed that the presence of nanosilica reduced Tg of epoxy polymer.

Thermal stability and dynamic mechanical behavior of functional multiphase boride ceramics/epoxy composites

2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Loss Modulus ◽  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Epoxy Composites ◽  
Scanning Calorimetry ◽  
Element Analysis ◽  
Reaction Heat ◽  
Dynamic Mechanical

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.

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.

NATURAL RUBBER NANOCOMPOSITES BASED ON NEW FIBROUS NANOFILLERS WITH IMPROVED BARRIER PROPERTIES FOR USE IN TIRE INNERLINER APPLICATIONS

2020 ◽  
pp. 000-000 ◽  
Author(s):  
K. P. Surya ◽  
Sanjay Bhattacharya ◽  
Rabindra Mukhopadhyay ◽  
Kinsuk Naskar ◽  
Anil K. Bhowmick
Keyword(s):  
Natural Rubber ◽  
Crack Growth ◽  
Cellulose Nanofibers ◽  
Barrier Properties ◽  
Dynamic Mechanical Properties ◽  
Hybrid Nanocomposites ◽  
Melt Mixing ◽  
Hybrid Filler ◽  
Dynamic Mechanical ◽  
Growth Properties

ABSTRACT Hybrid nanocomposites were prepared by predispersion of new nanofibers such as aramid nanofibers, carbon nanotubes, silicon carbide nanofibers (SiC), cellulose nanofibers, and graphite nanofibers in natural rubber (NR) latex prior to melt mixing in an internal mixer to ensure the exquisite dispersion of nanofibers in NR. The competency of these nanofibers in reinforcing NR as well as enhancing its barrier properties has not been widely investigated. The fabricated nanocomposites showed enhanced curing as well as mechanical and dynamic mechanical properties. Morphology of the composites was analyzed through electron microscopy. The increase in tortuosity created by the presence of the hybrid filler system consisting of carbon black and nanofibers was studied using permeability models. At higher tearing energies, it was seen that the nanofiber-reinforced composites showed comparable crack growth properties; however, at lower energies, the fabricated composites exhibited higher crack propagation rates compared with the control compound when studied using a tear fatigue analyzer. The improved mechanical, dynamic mechanical, and barrier properties along with comparable fatigue crack growth properties offer an opportunity to apply these systems in high-end applications such as a thinner tire inner liner with a higher NR blend ratio, which can result in improved processability and reduced hysteresis, fuel consumption, and cost.

Effects of Phenolic Oligomer on the Dynamic Mechanical Properties of Nitrile Butadiene Rubber

2011 ◽  
Vol 335-336 ◽  
pp. 120-123 ◽  
Author(s):  
Chang Su ◽  
Pan He ◽  
Li Huan Xu ◽  
Cheng Zhang
Keyword(s):  
Dynamic Mechanical Properties ◽  
Mechanical Analysis ◽  
Peak Position ◽  
Butadiene Rubber ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Nitrile Butadiene Rubber ◽  
Tan Δ ◽  
Damping Peak

In this article, the damping mechanism of organic hybrids consisting of Nitrile Butadiene Rubber (NBR) and phenolic oligomer 4-methyl-pheno reaction products of both dicyclopentadiene and isobutylene (MPDI) were investigated by dynamic mechanical analysis (DMA). It was shown that NBR/MPDI blends exhibit only one damping peak, which shifted to higher temperature with the increase of MPDI content, and the maximum of tan δ peak decreased slightly when the ratio of NBR/MPDI was no more than 100/20, and then increased when the ratio rised from 100/20 to 100/80. Fourier transform infrared spectrum (FT-IR) showed that the hydrogen bond were formed between -OH of MPDI and a-H of NBR. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements indicated that MPDI exhibit amorphous features, which was compatible with the blends. These may imply that much more stable damping material with both higher tan δ peak and controllable damping peak position can be achieved.

Application of dynamic mechanical analysis techniques to bismuth telluride based thermoelectric materials

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Witold Brostow ◽  
Kevin P. Menard ◽  
John B. White
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Bismuth Telluride ◽  
Polymeric Materials ◽  
Mechanical Analysis ◽  
Thermomechanical Properties ◽  
Thermal Transitions ◽  
Scanning Calorimetry ◽  
Dynamic Mechanical ◽  
Tan Δ ◽  
Te Material

Abstract Dynamic mechanical analysis (DMA) techniques are commonly applied to characterize polymer-based materials - but little if at all to characterize semiconductor thermoelectric (TE) materials. TE materials may be coupled with polymeric materials in advanced thermoelectric devices, and the knowledge of TE material properties will be useful in the choice of materials for future applications. We have obtained DMA results for both n-type and p-type bismuth telluride based TE materials. We find that tan δ values, indicative of viscoelastic energy dissipation modes, approach the values for glassy or semi-crystalline polymers, and are larger by more than a whole order of magnitude than the tan δ of structural metals. DMA thermal scans show clear hysteresis-type effects and a correlation with differential scanning calorimetry thermal transitions. DMA properties as a function of frequency are briefly discussed. Our results show that DMA techniques are useful in the evaluation of thermophysical and thermomechanical properties of these TE materials and of assembled coolers. The viscoelastic effects we report may provide a damping mechanism for severe stresses inherent to service conditions of the TE coolers.

Development of Low Phosphorous Engine Oils

2005 ◽  
Author(s):  
K. Patel ◽  
P. B. Aswath ◽  
R. L. Elsenbaumer
Keyword(s):  
Active Ingredient ◽  
High Performance ◽  
Decomposition Temperature ◽  
Fixed Number ◽  
Engine Oil ◽  
Additive Package ◽  
Scanning Calorimetry ◽  
Base Oil ◽  
Lower Weight ◽  
Wear Protection

ZDDP is the industry standard anti wear additive used by oil formulators for the past 50 years to provide the antiwear and load bearing capacity of engine oil. The breakdown of ZDDP results in the formation of sulfides and phosphates which provide anti-wear protection. In addition to its role as an anti-wear additive ZDDP also performs the role of an antioxidant. The performance of ZDDP is reduced by other parts of the additive package which include dispersants, pH stabilizers, and detergents. These constituents stabilize ZDDP and reduce its activity. The breakdown of ZDDP also creates S and P that can poison catalytic converters resulting in higher hydrocarbon and NOx emissions. GF-4 oils have lower ZDDP content to meet federal emission standards. In addition, to meet CAFE´ fuel economy standards, the industry is moving towards lower weight 5W-20 oil. The lower weight base oil coupled with lower ZDDP content have put additional constraints in developing high performance GF-4 oil. An additive package developed by Platinum Research Organization and the Tribology Group at University of Texas at Arlington is evaluated. This additive package enhances the activity of ZDDP and increases its anti-wear performance. This paper presents results from bench top tribology tests that were conducted to evaluate the performance of GF-4 oils with different amounts of ZDDP, additive package and an Fe based active ingredient. Results are discussed with respect to the extent of wear for a fixed number of wear cycles in a ball on cylinder test conducted under boundary conditions. In the presence of FeF3 active ingredient fully formulated oils with as little as 0.01% P exhibits antiwear performance comparable to oils with as much as 0.05% P and oils with 0.05%P are comparable to oils with 0.1%P. Differential scanning calorimetry indicates that the decomposition temperature of ZDDP is reduced by as much as 20°C in the presence of FeF3. This reduced decomposition temperature results in the efficient formation of anti-wear films even with lower ZDDP amounts.

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