The Effect of Blending Ratio on Mechanical Properties of Polylactic Acid (PLA) / Ethylene Vinyl Acetate (EVA)

2014 ◽  
Vol 554 ◽  
pp. 194-198
Author(s):  
Abdul Manan Siti Najihah ◽  
Zurina Mohamad

The objective of the study is to improve the mechanical properties of Polylactic acid (PLA)/Ethylene Vinyl Acetate (EVA) blend. The blend was prepared via twin screw extruder and compression molding with different composition. The effect of different blend ratio on the mechanical properties was investigated by Tensile and Flexural test. The mechanical properties of PLA shown an improvement compared to the pure PLA with the incorporation of EVA. The flexural modulus increased with the increased of EVA content, while the tensile and flexural strength also increased when EVA increased. The optimum tensile and flexural strength was at 90PLA/10EVA of blends ratio.

2015 ◽  
Vol 735 ◽  
pp. 57-60
Author(s):  
Abdul Manan Siti Najihah ◽  
Zurina Mohamad

In this study, ethylene vinyl acetate (EVA) was blended with Polylactic acid (PLA) in order to enhance the mechanical properties of PLA. PLA/EVA blend was melt blended in a twin screw extruder and compression molding with various EVA content (0-20% by weight) and the tensile and morphological properties were examined. The morphological behaviours play an important role in influencing the tensile properties of PLA. The smaller discrete EVA particle in PLA matrix had increased the properties of PLA compared with the one with elongated morphology.


2014 ◽  
Vol 554 ◽  
pp. 62-65 ◽  
Author(s):  
Noora Tiqah Mohamad Fauzi ◽  
Zurina Mohamad

The objective of this study is to investigate the effect of sepiolite concentration (2-10 phr) on the mechanical properties of polyamide 6 (PA6) / ethylene vinyl acetate (EVA) blend at the ratio 80/20. Twin screw extruder and injection moulding machine were used to prepare the samples. The strength and modulus of flexural was increased until 6 phr of sepiolite content. On the other hand, the impact strength of PA6/EVA/sepiolite composite was decreased gradually as sepiolite content increased.


2014 ◽  
Vol 970 ◽  
pp. 259-262
Author(s):  
Hossein Cheraghi Bidsorkhi ◽  
Zurina Mohamad

Ethylene Vinyl Acetate (EVA)/Sepiolite nanocomposites were prepared by melt extrusion using a counter-rotating twin-screw extruder followed by injection molding. Sepiolite was loaded in EVA is varies at 1, 3, 5 and 7 wt%. The mechanical properties of EVA/Sepiolite nanocomposites were studied through tensile test. The flame retardancy of nanocomposites were studied for limiting oxygen index (LOI). LOI tests show that the flame retardancy of nanocomposites were increased with increase ratio of sepiolite in EVA/Sepiolite nanocomposite. The tensile properties of EVA/Sepiolite nanocomposites were also increased with increased Sepiolite content in nanocomposites.


2015 ◽  
Vol 1119 ◽  
pp. 283-287
Author(s):  
Sarit Liprapan ◽  
Thumnoon Nhujak ◽  
Pranut Potiyaraj

The objective of this study is to prepare α-cellulose reinforced poly (butylene succinate) composites (PBS/α-cellulose). The effect of amount α-cellulose on the mechanical properties of the composites was investigated. To improve interfacial interaction between PBS and α-cellulose, glycidyl methacrylate grafted poly (butylene succinate) (PBS-g-GMA) was used as a compatibilizer. Mechanical properties of PBS composites prepared by using a twin-screw extruder were investigated. The mechanical properties of PBS/α-cellulose decreased due to the agglomeration of α-cellulose. Nevertheless, tensile strength, Young’s modulus and flexural strength of PBS composites were improved after the incorporation of PBS-g-GMA. The optimum loading of PBS-g-GMA and α-cellulose in the PBS was found to be 5 and 6 phr.


2020 ◽  
Vol 856 ◽  
pp. 331-338
Author(s):  
Sirisart Ouajai ◽  
Suttinun Phongtamrug

This research has focused on the effect of modified cellulose and clay on the thermal and mechanical properties of PLA bio-nanocomposite. Cellulose was chemically modified with silane coupling agent in order to enhance compatiblization with PLA. Successful modification was confirmed by Fourier Transform Infrared Spectroscopy and EDX-SEM. PLA was compounded with various amounts and ratios of the modified cellulose and clay by a twin-screw extruder. Thermal properties of the bio-nanocomposites were characterized by Thermogravimetric Analysis and Differential Scanning Calorimetry. Glass transition temperature of the bio-nanocomposite slightly decreased whereas melting temperature remained constant when the amount of both fillers was increased. In addition, crystallization behaviour of PLA has been influenced by the type and amount of the fillers. Clay showed a greater effect on the crystallization of PLA than the modified cellulose and unmodified one, respectively. The flexural modulus of the composite containing equal amount between clay and cellulose was increased with an increasing in fillers contents. But the flexural and impact strength of composite were gradually decreased with an increase in fillers contents. Variation of clay and cellulose ratio resulted in the change of mechanical properties. The composite containing higher ratio between clay:cellulose or cellulose:clay showed a better mechnical properties comparing to the ratio of clay:cellulose equal to 1:1.


2011 ◽  
Vol 221 ◽  
pp. 27-31 ◽  
Author(s):  
Rong Xian Ou ◽  
Qing Wen Wang ◽  
Fei Pin Yuan ◽  
Bao Yu Liu ◽  
Wei Jun Yang

Hydrolyzed Kevlar fibers (KFs) were compouded into high-density polyethylene (HDPE) with wood flour (WF) by twin-screw/single-screw extruder to investigate the reinforcement effects of KFs on the mechanical properties of conventional WF/HDPE composites. Maleated HDPE (MAPE) was used as a compatibilizer. The mechanical properties significantly improved as the KFs loading increases in the presence of 4% MAPE, such as tensile strength 14.7%, tensile modulus 12.4%, flexural strength 22.2%, flexural modulus 22.4%, and impact strength 41.7% with 2 wt.% KFs compared to WF/HDPE composite with MAPE. The fiber matrix morphology of the interface region in the composites was examined using scanning electron microscopy (SEM).


2014 ◽  
Vol 1033-1034 ◽  
pp. 869-872
Author(s):  
Kun Yan Wang

Polypropylene (PP)/ethylene-vinyl acetate (EVA) blends were prepared using a twin-screw extruder by melt blending method. The influences of the EVA contents in PP/EVA blends on crystallization behavior and mechanical properties were investigated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD results show that the EVA not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. DSC results showed that the melting point and crystallization point decreased when EVA added to the blend. The tensile properties of PP/EVA blend become much better.


Author(s):  
Ayşe Atay DDS, PhD ◽  
Elçin Sağirkaya DDS, PhD

The aim of this study was to evaluate mechanical properties of six new-generation all-ceramic materials for CAD/CAM (Lava Ultimate [LU], VITA Mark II [VM], InCoris TZI [IC], IPS e.max CAD [EM], VITA Suprinity [VS], IPS Empress CAD [EC]) and two different provisional restoration CAD/CAM materials (Telio CAD [TC], Vita CAD-Temp [VC]) after different storage conditions. 36 bar-shaped samples of 4 mm in width and 14 mm in length with 1.2 mm thicknesses were prepared from each material group (N=288). The specimens from each material were kept under three different storage conditions (n=12): under dry conditions at room temperature; 37°C distilled water for 7 days; and 37°C distilled water for 7 days followed by 10,000 thermal cycles. All specimens were subjected to a 3-point flexural test with a crosshead speed of 1.0 mm/min. The specimens were loaded until failure. Twelve fractured specimens after the flexural test from each group were used for the Vickers hardness test (under 300 gf of loading in 15 seconds). The flexural modulus, flexural strength and Vickers hardness values were separately analyzed with two-way analysis of variance, Tukey’s multiple comparison tests at a significance level of p<0.05. There were statistically significant differences between materials and storage conditions according to flexural modulus, flexural strength and Vickers hardness values (p<0.05).  The flexural strength, flexural modulus and Vickers hardness values of LU, VC, TC, VS and IC decreased after water storage followed by thermal cycling (p<0.05). The mechanical properties of provisional restoration CAD/CAM materials had showed a significantly decrease after water storage followed by thermal cycles but their mechanical properties were acceptable for fabrication of provisional restorations. The mechanical properties of VM, EC and EM were not affected by different storage conditions whereas IC and VS were affected.


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