scholarly journals Characterization of Low-Density Polyethylene and LDPE-Based/Ethylene-Vinyl Acetate with Medium Content of Vinyl Acetate

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2352
Author(s):  
Nga Thi-Hong Pham
Keyword(s):  
Flexural Strength ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Spherical Particles ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Elongation At Break ◽  
Polar Polymers ◽  
Acetate Copolymer

Low-density polyethylene (LDPE) and ethylene vinyl acetate copolymer (EVA), which are non-polar and polar polymers, are immiscible and form a polyphase system. In this study, LDPE was mixed with 2.5%, 5%, 7.5%, 10%, 12.5% Ethylene-vinyl acetate (EVA-28) with a medium content of vinyl acetate (28% VA), respectively by injection molding machine and LDPE. Tensile strength and flexural strength were tested according to ASTM D638-02 standard and ISO 178 standard. The results showed that adding EVA-28 increased the elongation at break of the LDPE/2.5% EVA, LDPE/5% EVA and LDPE/10% EVA blend samples. In addition, the tensile and flexural strength of the LDPE/EVA blend decreases gradually as the EVA-28 content in the blend increases. The hardness decreases with the increasing EVA-28 content. EVA-28 spherical particles appeared scattered on the surface of the LDPE matrix, in the highest EVA-28 percent sample (12.5% EVA-28), the number of particles appeared to be quite a lot, and was dispersed quite evenly on the surface. The LDPE/EVA-28 blend achieved a higher elongation at the break than LDPE, in which 10% EVA-28 gives the highest elongation at break.

Morphology and Mechanical Properties of LDPE, EVA and Fly Ash Composites

2020 ◽  
Vol 869 ◽  
pp. 76-81
Author(s):  
Vu Minh Trong ◽  
Bui Dinh Hoan
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Ethylene Vinyl Acetate ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Melt Mixing ◽  
Elongation At Break ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer ◽  
Morphology And Mechanical Properties

The fly ash from Pha Lai power plant was modified by vinyltrimetoxysilan (VTMS). The polymer composites based on low-density polyethylene (LDPE), ethylene vinyl acetate copolymer (EVA) and fly ash (FA) without and with vinyltrimetoxysilan (VTMS) modification were prepared by melt mixing in a Haake Rheomixer. The tensile strength and elongation at break of the LDPE/EVA/VFA composites were also higher than those of the LDPE/EVA/FA composites. The FESEM images proved that FA-VTMS particles disperse more regularly in the polymer matrix in comparison with FA without VTMS modification. In addition, the surface modification of the FA reduced the size of agglomeration of FA particles.

Electron-beam irradiation of low density polyethylene/ethylene vinyl acetate blends

2013 ◽  
Vol 33 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Maziyar Sabet ◽  
Azman Hassan ◽  
Chantara Thevy Ratnam
Keyword(s):  
Tensile Strength ◽  
Electron Beam ◽  
Vinyl Acetate ◽  
Electron Beam Irradiation ◽  
Ethylene Vinyl Acetate ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Beam Irradiation ◽  
Elongation At Break ◽  
Gel Content

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.

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