Effect of organoclay loading and electron beam irradiation on the physico-mechanical properties of low-density polyethylene/ethylene-vinyl acetate blend

2011 ◽  
Vol 22 (12) ◽  
pp. 2352-2359 ◽  
Author(s):  
A. Shojaei ◽  
A. Behradfar ◽  
N. Sheikh
2013 ◽  
Vol 33 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Maziyar Sabet ◽  
Azman Hassan ◽  
Chantara Thevy Ratnam

Abstract In this work, the properties of electron-beam irradiated low density polyethylene (LDPE), ethylene vinyl acetate (EVA) and blends were investigated. EVA addition had an enhancement effect on crosslinking of irradiated LDPE/EVA blends. The measured gel content increase of the blends and the improvement of thermal elongation, tensile strength, elongation at break, thermal aging and heat deformation, have confirmed the positive effects of electron-beam irradiation on the blend properties. The crystallinity of the blends decreased with irradiation. The gel content and hot set tests showed that the degree of crosslinking in the amorphous regions was dependent on the dose and blend composition. Increasing the EVA content resulted in tighter network structures. A significant improvement in the tensile strength of the neat EVA samples was obtained upon electron-beam irradiation up to 210 kGy. The irradiated LDPE/EVA blends showed improved tensile strength and elongation at break, when compared to LDPE. The enhanced irradiation crosslinking of the LDPE/EVA blends was proportional to the good compatibility and the increasing degree of the amorphous region’s content of the LDPE/EVA blends. The possible degradation mechanism of LDPE/EVA blends was discussed quantitatively with a novel method step analysis process of irradiated LDPE/EVA blends in the thermal gravimetric analysis (TGA) technique. It was found, with measuring thermal conductivity (k) and specific heat capacity (Cp) of the blends, that the k values of the LDPE samples at a prescribed temperature range decreased with increasing irradiation. An increase in the crystallinity led to an increase in the k values and a decrease in the Cp values of the LDPE samples. Irradiation below 150 kGy decreased the Cp (at 40°C) and k in average values, whereas increasing the EVA made enhanced the Cp and k values of LDPE/EVA blends at each irradiation. The surface resistance and volume resistivity (VR) of the blends reached a maximum at a 170 kGy irradiation and 30 wt% of EVA. Increasing the amount of EVA contents resulted in enhancement of the dielectric loss factor for the irradiated blends.


2001 ◽  
Vol 74 (5) ◽  
pp. 815-833 ◽  
Author(s):  
S. Chattopadhyay ◽  
T. K. Chaki ◽  
Anil K. Bhowmick

Abstract New thermoplastic elastomers have been prepared from the blends of metallocene-based polyolefins (Engage) with low-density polyethylene (LDPE), and ethylene-vinyl acetate copolymers (EVA) of different grades with LDPE by electron beam modification. Structural changes of these blends with or without sensitizer in presence of irradiation have been evaluated by X-ray diffraction (XRD) and differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) in conjunction with atomic force microscopy (AFM) indicate the soft rubber domain in the continuous plastic matrix. Significant improvements of mechanical, dynamic mechanical and set properties have been obtained by electron beam modification, retaining its reprocessibility characteristics. Effects of ditrimethylol propane tetraacrylate (DTMPTA) as radiation sensitizer have also been evaluated from the mechanical, dynamic mechanical properties and reprocessibility.


2014 ◽  
Vol 493 ◽  
pp. 703-708
Author(s):  
Farizah Hamid ◽  
Suffiyana Akhbar ◽  
Ku Halim Ku Hamid ◽  
Abdul Rahman Mohd Faizal

The effect of electron beam irradiation on mechanical properties of Ethylene vinyl acetate (EVA) with polyamide 6/high density polyethylene/HDPE-g-MAH and montmorillonite (MMT) were prepared by melt blending the characterization were investigated. The composites were characterized by Fourier Transform Infrared (FTIR) spectrophotometer and Thermogravimetric Analyzer (TGA) The samples were cross-linked by electron beam and irradiated at the dosage range of 0-200 kGy and 3.0 MeV. The mechanical properties of the samples which are tensile test and flexural test were measured by universal tensile machine whiles hardness was measured using Rockwell hardness tester. The gel content was performed to determine the formation of crosslinking and it showed improvement with increase dose up to 150 kGy. The result shows the increasing of tensile strength, tensile modulus, and hardness at the dosage 150 kGy but slightly decline at dose up to 200 kGy. Meanwhile TGA test showed that both irradiated and unirradiated samples have same trend characterization but irradiated samples are slightly more thermal stability. As a conclusion the electron beam irradiation enhance mechanical and thermal properties of ethylene vinyl acetate/polyamide 6/high density polyethylene nanocomposite.


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