Natural Rubber-Whisker Alumina Fiber Composite Materials for Mechanical and Thermal Insulation Applications

2018 ◽  
Vol 789 ◽  
pp. 221-225
Author(s):  
Nattapol Dedruktip ◽  
Wasan Leelawanachai ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Thermal Conductivity ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Natural Rubber ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Curing Temperature ◽  
Mechanical And Thermal Properties ◽  
Alumina Fiber ◽  
Elongation At Break

Alumina fiber is a ceramic material used as a dispersed phase or filler to reinforce the mechanical and improve thermal properties of natural rubber via vulcanization process at curing temperature 150°C. The amount of alumina fiber added in natural rubber was varied from 0 to 50 phr on 100 phr of natural rubber in a sulfur curing system. Adding 10 phr alumina fiber affects to obtain the best natural rubber composite samples having good mechanical and thermal properties. Tensile strength, elongation at break, Young’s modulus and thermal conductivity of adding 10 phr whisker alumina fiber encoded NR-Al-10 are equal to 14.38±1.95 MPa, 1038.4±41.45%, 545.63±25.67 MPa and 0.2376±0.0003 W/m.K, respectively, better than those of pure natural rubber compounds without adding alumina fiber. Tensile strength, elongation at break, Young’s modulus and thermal conductivity of natural rubber without adding alumina fiber are equal to 14.06±6.03 MPa, 949.41±52.15%, 496.32±8.54 MPa and 0.2500±0.0003 W/m.K, respectively.

Mechanical and Thermal Properties of Rubber Toughened Poly(Lactic Acid)

2015 ◽  
Vol 1125 ◽  
pp. 222-226 ◽  
Author(s):  
Mohd Shaiful Zaidi Mat Desa ◽  
Azman Hassan ◽  
Agus Arsad ◽  
Nor Nisa Balqis Mohammad
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Impact Strength ◽  
Natural Rubber ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Rubber Blends

The effect of rubber toughening on mechanical and thermal properties of poly (lactic acid) (PLA) was investigated by using three types of rubbers; natural rubber (NR), epoxidized natural rubber (ENR) and core-shell rubber (CSR). The PLA/rubber blends were prepared by melt blending in a counter-rotating twin-screw extruder, where the rubber content for all blends was kept at 5 wt%. It was found that the addition of the rubbers increased the impact strength for all blends as compared to pure PLA. On the other hand, all PLA/rubber blends showed notable decrease of Young’s modulus especially for PLA/NR blend which decreased by 72% than pure PLA. Similarly, significant decrease of tensile strength was also observed for all PLA/rubber blends. PLA/ENR blend showed a morebalance mechanical properties with fairly significant improvement of impact strength and moderate decrease of tensile strength, Young’s modulus and elongation at break. In general, PLA/NR blend showed the highest overall impact strength, while the PLA/CSR showed the highest tensile strength and Young’s modulus among the blends. Thermal analysis revealed that the Tg of PLA decreased with incorporation of the three types of rubbers with NR showing the largest decrease. This study indicates that NR, ENR and CSR are effective in enhancing toughness of PLA

scholarly journals Effect of Defects on the Mechanical and Thermal Properties of Graphene

Nanomaterials ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 347 ◽  
Author(s):  
Maoyuan Li ◽  
Tianzhengxiong Deng ◽  
Bing Zheng ◽  
Yun Zhang ◽  
Yonggui Liao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Strain Rate ◽  
Young’S Modulus ◽  
Fracture Strength ◽  
Fracture Strain ◽  
Young's Modulus ◽  
Pristine Graphene ◽  
Mechanical And Thermal Properties

In this study, the mechanical and thermal properties of graphene were systematically investigated using molecular dynamic simulations. The effects of temperature, strain rate and defect on the mechanical properties, including Young’s modulus, fracture strength and fracture strain, were studied. The results indicate that the Young’s modulus, fracture strength and fracture strain of graphene decreased with the increase of temperature, while the fracture strength of graphene along the zigzag direction was more sensitive to the strain rate than that along armchair direction by calculating the strain rate sensitive index. The mechanical properties were significantly reduced with the existence of defect, which was due to more cracks and local stress concentration points. Besides, the thermal conductivity of graphene followed a power law of λ~L0.28, and decreased monotonously with the increase of defect concentration. Compared with the pristine graphene, the thermal conductivity of defective graphene showed a low temperature-dependent behavior since the phonon scattering caused by defect dominated the thermal properties. In addition, the corresponding underlying mechanisms were analyzed by the stress distribution, fracture structure during the deformation and phonon vibration power spectrum.

Effect of Ce Substitution on Mechanical and Thermal Properties of Tetragonal YSZ: First-Principles Calculations

2015 ◽  
Vol 1120-1121 ◽  
pp. 73-84
Author(s):  
Lei Jin ◽  
Pei Zhong Li ◽  
Guo Dong Zhou ◽  
Wei Gao ◽  
Jiang Ning Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Sound Velocity ◽  
Young’S Modulus ◽  
Elastic Constants ◽  
First Principles ◽  
Density Functional ◽  
Young's Modulus ◽  
Mechanical And Thermal Properties ◽  
Ce Substitution

The effect of impurity Ce on the mechanical and thermal properties of tetragonal ZrO2 stabilized by rare earth element Y (YSZ) have been studied using first principles density functional theory within generalized gradient approximation (GGA) for the exchange correlation potential. The predicted elastic constants indicate that YSZ and Ce doped YSZ (CeYSZ) are mechanically stable structures. And then the numerical estimates of bulk modulus, shear modulus, Young’s modulus, Poisson’s ratio, sound velocity and minimum thermal conductivity were performed using the calculated elastic constants and analyzed for the first time. The values of sound velocity from different orientations are also reported. The agreement between the results of the available experiments and our calculations was satisfactory. Our calculated results indicate that Young’s modulus, hardness, mean sound velocity and minimum thermal conductivity of YSZ can be decreased by Ce substitution. The reasons are from the “softened” Ce-O bond strength using bond population and relative volume change under external hydrostatic pressure. Chemical bonding nature was also analyzed from the density of states and electron density difference.

Comparison between Mechanical and Thermal Properties of Polylactic Acid and Natural Rubber Blend Using Calcium Carbonate and Vetiver Grass Fiber as Fillers

2011 ◽  
Vol 410 ◽  
pp. 59-62 ◽  
Author(s):  
Punmanee Juntuek ◽  
Chaiwat Ruksakulpiwat ◽  
Pranee Chumsamrong ◽  
Yupaporn Ruksakulpiwat
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Thermal Properties ◽  
Calcium Carbonate ◽  
Impact Strength ◽  
Natural Rubber ◽  
Poly Lactic Acid ◽  
Mechanical And Thermal Properties ◽  
Vetiver Grass ◽  
Elongation At Break

From our previous study, natural rubber (NR) was used to improve toughness of poly (lactic acid) (PLA). Impact strength and elongation at break of PLA was increased when adding NR. Moreover, by using NR-g-GMA as compatibilizer for PLA and NR blend, impact strength and elongation at break was improved. However, tensile strength and modulus of PLA/NR blend with and without NR-g-GMA were decreased. In this study, calcium carbonate (CaCO3) and vetiver grass fiber were used as fillers in PLA/NR blend. With the addition of CaCO3 into PLA/NR blend with NR-g-GMA, impact strength and modulus of the composite were further increased with a loss in tensile strength. In contrast, the addition of vetiver grass fiber into PLA/NR blend with NR-g-GMA led to an increase in tensile strength and modulus and a decrease in impact strength and elongation at break. The onset degradation temperatures of PLA composites were lower than that of PLA and PLA/NR blend.

scholarly journals Mechanical, thermal and adhesion characteristics of natural rubber/epoxidised natural rubber (NR/ENR 25) blends containing natural microbentonite

2021 ◽  
Vol 912 (1) ◽  
pp. 012073
Author(s):  
B Wirjosentono ◽  
Tamrin ◽  
A H Siregar ◽  
D A Nasution
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Thermal Properties ◽  
Natural Rubber ◽  
Young’S Modulus ◽  
Water Uptake ◽  
Young's Modulus ◽  
Scanning Calorimetry ◽  
Adhesion Properties ◽  
Hydrophilic Surfaces

Abstract Blending of natural rubber (NR) with epoxidised natural rubber (ENR 25) improved engineering characteristics of the blends, especially on their toughness, resistant to mineral oil, as well as their adhesion on hydrophilic surfaces, such as metals and concretes. Addition of natural microbentonite was expected not only to improve the blend’s compatibility, but also to enhance their thermal characteristics and adhesion properties on hydrophilic surfaces. In this works Indonesian natural rubbers (SIR-10) have been blended with epoxidised natural rubber (ENR-25) in a reflux rector in xylene solution with addition of various loading of natural microbentonite as fillers. Mechanical properties of the blends were characterized using tensile tests (tensile strength, elongation at break, and Young’s modulus), whereas their thermal properties were measured using differential scanning calorimetry (DSC). Furthermore, to estimate their adhesion properties on hydrophilic surfaces, the blends were immersed in water, and their water uptake were measured gravimetrically, as well as changes on their mechanical properties. It was found that optimum composition of natural microbentonite in the blend with highest tensile strength and Young’s modulus was obtained when loading of the filler was 4 phr. When compared to that without filler, DSC thermogram of the optimum blend showed better thermal properties (lower heat release decreased from 903.10 J/g to 420.17 J/g) although the decomposition temperatures did not change considerably (407.8° to 408.09°C). Whereas the later also exhibited higher water uptake (0.05 to 0.34 %) and still with acceptable mechanical properties as adhesive materials.

Effect of Sc, Y, Yb, Hf, Ce on Mechanical and Thermal Properties of La2Zr2O7: First-Principles Calculations

2015 ◽  
Vol 1120-1121 ◽  
pp. 85-93 ◽  
Author(s):  
Lei Jin ◽  
Pei Zhong Li ◽  
Chun Zhu Jiang ◽  
Guo Dong Zhou ◽  
Hai Bin Zhou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Sound Velocity ◽  
Young’S Modulus ◽  
Debye Temperature ◽  
Elastic Constants ◽  
First Principles ◽  
Young's Modulus ◽  
Elastic Stiffness ◽  
Mechanical And Thermal Properties

In order to achieve better understanding of the effect of dopant (Sc, Y, Yb, Hf and Ce) on elastic stiffness and thermal properties of La2Zr2O7. The related calculations were performed using the first principles methods. The predicted elastic constants indicate that La2Zr2O7 and oxidations-La2Zr2O7 (oxidations refer to Sc2O3, Y2O3, Yb2O3, HfO2 and CeO2) are mechanically stable structures. And then the numerical estimates of bulk modulus, shear modulus, Young’s modulus were performed using the calculated elastic constants. After these mechanical properties are obtained, sound velocity, Debye temperature and theoretical minimum thermal conductivity of La2Zr2O7 and oxidations-La2Zr2O7 are calculated and analyzed in detail. The available experimental results and our calculations are basically satisfactory. The calculated results indicate that Young’s modulus, mean sound velocity, Debye temperature and minimum thermal conductivity of La2Zr2O7 can be decreased by dopants. CeO2 has extraordinary ability to decrease thermal conductivity in these dopant oxidations.

Green Composites of Poly(Lactic Acid)/Epoxidized Natural Rubber Filled with Coir Fibers

2020 ◽  
Vol 845 ◽  
pp. 39-44
Author(s):  
Woraporn Kiwjaroun ◽  
Saowaroj Chuayjuljit ◽  
Phasawat Chaiwutthinan ◽  
Anyaporn Boonmahitthisud
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Impact Strength ◽  
Natural Rubber ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Poly Lactic Acid ◽  
Green Composites ◽  
Elongation At Break ◽  
The Impact

The aim of this study is to prepare green composites from poly (lactic acid) (PLA) and in-house epoxidized natural rubber (ENR) with coir fibers (CFs). In-house ENR with medium epoxidation degree (about 35 mole% epoxidation) was first prepared via ‘in situ’ epoxidation of natural rubber latex. PLA was melt-mixed with three loadings (10, 20 and 30 wt%) of ENR on a twin-screw extruder, followed by injection molding to observe their mechanical properties (impact strength, tensile strength, Young’s modulus and elongation at break) and thermal stability. The results showed that the addition of the ENR enhanced the impact strength and elongation at break, but deteriorated tensile strength, Young’s modulus and thermal stability of the blends. From mechanical properties consideration, the 90/10 PLA/ENR blend was selected for preparing green composites with different amounts of CFs (5, 10 and 20 phr). It was found that the incorporation of CFs improved tensile strength and Young’s modulus. However, the impact strength, elongation at break and thermal stability of the green composites decreased as compared to those of the neat 90/10 PLA/ENR blend.

scholarly journals CHEMICALLY CHITOSAN MODIFIED WITH METHYL METHACRYLATE AND ITS EFFECT ON MECHANICAL AND THERMAL PROPERTIES OF POLYPROPYLENE COMPOSITES

2013 ◽  
Vol 13 (2) ◽  
pp. 114-121 ◽  
Author(s):  
Faisal Amri Tanjung ◽  
Salmah Husseinsyah ◽  
Kamarudin Hussin ◽  
Iqmal Tahir
Keyword(s):  
Tensile Strength ◽  
Thermal Properties ◽  
Methyl Methacrylate ◽  
Young’S Modulus ◽  
Fourier Transforms ◽  
Young's Modulus ◽  
Filler Loading ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Pp Composites

Effects of methyl methacrylate on the properties of chitosan-filled polypropylene (PP) composites has been investigated. Mechanical and thermal properties of the composites were analyzed according to ASTM D 638-91, thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). The results showed that tensile strength of PP composites decreased upon the addition of chitosan, while Young's modulus improved. At a similar filler loading, the treated PP/chitosan composites were found to have higher tensile strength and Young's modulus as compared with the untreated composites. Thermal analysis results showed that thermal stability and crystallinity of the treated composites were higher than the untreated ones. Scanning electron microscopy (SEM) and Fourier transforms infrared (FTIR) studies revealed less detached filler from matrix on tensile surface of the treated composites as an evidence of enhanced filler-matrix interfacial adhesion due to formation of ester-bridge between the chitosan and the methyl methacrylate.

Effect of Castor Oil Impregnation on the Physical and Mechanical Properties of Bacterial Cellulose

2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bacterial Cellulose ◽  
Young’S Modulus ◽  
Castor Oil ◽  
Young's Modulus ◽  
Physical And Mechanical Properties ◽  
Scanning Electron Micrographs ◽  
Elongation At Break ◽  
Acetone Water

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.

Tensile and water absorption properties of solvent cast biofilms of sugarcane leaves fibre-filled poly(lactic) acid

2018 ◽  
Vol 33 (3) ◽  
pp. 289-304 ◽  
Author(s):  
Kuhananthan Nanthakumar ◽  
Chan Ming Yeng ◽  
Koay Seong Chun
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Water Absorption ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Poly Lactic Acid ◽  
Infrared Analysis ◽  
Absorption Properties ◽  
Elongation At Break ◽  
Bleaching Treatment

This research covers the preparation of poly(lactic acid) (PLA)/sugarcane leaves fibre (SLF) biofilms via a solvent-casting method. The results showed that the tensile strength and Young’s modulus of PLA/SLF biofilms increased with the increasing of SLF content. Nevertheless, the elongation at break showed an opposite trend as compared to tensile strength and Young’s modulus of biofilms. Moreover, water absorption properties of PLA/SLF biofilms increased with the increasing of SLF content. In contrast, the tensile strength and Young’s modulus of biofilms were enhanced after bleaching treatment with hydrogen peroxide on SLF, but the elongation at break and water absorption properties of bleached biofilms were reduced due to the improvement of filler–matrix adhesion in biofilms. The tensile and water properties were further discussed using B-factor and Fick’s law, respectively. Furthermore, the functional groups of unbleached and bleached SLF were characterized by Fourier transform infrared analysis.

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