Calcium Stearate and Alumina Trihydrate Addition of Irradiated LDPE, EVA and Blends with Electron Beam

2013 ◽  
Vol 290 ◽  
pp. 31-37 ◽  
Author(s):  
Maziyar Sabet ◽  
Mohd Syafiq Bin Anuwar

Irradiation effects on the properties of alumina trihydrate (ATH) / low-density polyethylene (LDPE)/ ethylene vinyl acetate (EVA) / calcium stearate (CS) have been studied and confirmed that EVA and CS addition to the polymeric blends have improved the mechanical properties. ATH addition increased the cross-linking density and improved the blend reinforcing factor but deteriorated the blend mechanical properties. CS addition made ease the ATH dispersion inside polymer matrix. CS addition optimum value in blends was 3 phr and CS addition above 3 phr value deteriorated the blends mechanical properties.

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 606 ◽  
pp. 265-268 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Jan Navratil ◽  
...  

Radiation cross-linking gives inexpensive commodity plastics and technical plastics the mechanical, thermal, and chemical properties of high-performance plastic. This upgrading of the plastics enables them to be used in conditions which they would not be able to with stand otherwise. The irradiation cross-linking of thermoplastic materials via electron beam or cobalt 60 (gammy rays) is performed separately, after processing. Generally, ionizing radiation includes accelerated electrons, gamma rays and X-rays. Radiation processing with an electron beam offers several distinct advantages when compared with other radiation sources, particularly γ-rays and x-rays. The process is very fast, clean and can be controlled with much precision. There is no permanent radioactivity since the machine can be switched off. In contrast to γ-rays and x-rays, the electron beam can steered relatively easily, thus allowing irradiation of a variety of physical shapes. The energy-rich beta rays trigger chemical reactions in the plastics which results in networking of molecules (comparable to the vulcanization of rubbers which has been in industrial use for so long). The energy from the rays is absorbed by the material and cleavage of chemical bonds takes place. This releases free radicals which in next phase from desired molecular bonds. This article describes the effect of radiation cross-linking on the surface and adhesive properties of low-density polyethylene.


2020 ◽  
Vol 869 ◽  
pp. 76-81
Author(s):  
Vu Minh Trong ◽  
Bui Dinh Hoan

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.


2018 ◽  
Vol 51 (3) ◽  
pp. 211-223
Author(s):  
M Aouinet ◽  
K Djakhdane ◽  
A Dehbi ◽  
D Castronuovo ◽  
P Picuno

The low-density polyethylene films used for greenhouse roof were naturally weathered for 9 months in harsh climatic conditions (Tiaret region, Algeria). The changes in the mechanical properties have been measured by tensile and creep-recovery tests. The measurements were carried out for both monolayer and tri-layer films. The anisotropic character of the films is preserved during ageing. The improvement in the creep resistance via cross-linking for both monolayer and tri-layer films affects different deformations. The results revealed that the degradation performance of these new tri-layer films is found to be quite better than that of the monolayer film, with regard to the mechanical properties.


2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
F. Soriano-Corral ◽  
L. A. Calva-Nava ◽  
J. F. Hernández-Gámez ◽  
E. Hernández-Hernández ◽  
P. González-Morones ◽  
...  

Agave fibers (AF) were incorporated either pristine (AFp) or surface treated by ethylene plasma (AFm) in low-density polyethylene (LDPE)/ethylene vinyl acetate (EVA) blends at a ratio of 1 : 1 and foamed by chemical means. The role of the AF content (3, 6, 9, 12, and 15 wt.%) and its surface modification on the cellular morphology and mechanical properties of LDPE/EVA/AF foams under compression is investigated herein. Fourier transform-infrared spectroscopy, contact angle, and water suspension of AF suggest that plasma treatment using ethylene successfully modifies the surface nature of AF from hydrophilic to hydrophobic. AF and the surface treatment have an important role on the morphological properties of the foams. Composite foams reinforced with 12 wt.% AFm exhibited the highest mechanical properties improvements. At this fiber content, the composite foams enhanced 30% of the compressive modulus and 23% of the energy absorption under compression with respect to the neat polymer blend foam, as a result to the formation of more uniform cells with smaller size and the enhancement of compatibility and spatial distribution of the AFm in the polymer composite foams due to thin clusters of polyethylene-like polymer deposited on the AF surface.


2013 ◽  
Vol 33 (7) ◽  
pp. 651-657 ◽  
Author(s):  
Maziyar Sabet ◽  
Hassan Soleimani ◽  
Azman Hassan ◽  
Chantara Thevy Ratnam

Abstract The effects of the addition different fillers, such as calcium stearate (CS), aluminum trihydrate (ATH), and magnesium hydroxide (MH), on the properties of low-density polyethylene/ethylene vinyl acetate (LDPE/EVA) compounds were studied. It was determined that the adhesion forces among MH and LDPE/EVA compounds were stronger than those among analogue compounds containing ATH in each irradiated sample. The gel content (GC) values of irradiated compounds containing ATH were higher than those of the analogue MH compounds, and CS addition enhanced the GC values of all compounds in each irradiated sample. The density values of compounds with MH content were higher than those of analogue compounds containing ATH in each irradiated sample. It was shown that all pristine compounds whose density was compared with irradiated samples had maximum values. Addition of CS and enhancing irradiation to polymer compounds reduced the density values. Compounds with high CS contents and were highly irradiated showed high tensile strength (TS) values. The TS values of compounds containing ATH were lower than those of analogue compounds containing MH in each irradiated sample. ATH or MH addition to polymer matrices reduced the elongation at break (EB) values in each irradiated sample. The EB values of compounds containing ATH were higher than those of compounds containing MH in each irradiation range. CS addition improved polymer chain flexibility and enhanced the compounds’ EB values with irradiation.


Sign in / Sign up

Export Citation Format

Share Document