Comparison of optical properties and mechanical/electrical degradation of some low density polyethylene-and polypropylene-based polymer blends

Abstract

Boydağ, Fatma Şenel (Dogus Author)In this study, the optical properties as well as mechanical and electrical degradation of low-density polyethylene (LDPE)/polypropylene fiber (PP fiber) (10–50% PP fiber), polypropylene (PP)/PP fiber (10–50% PP fiber), and LDPE/diamond (0.1–3% diamond) blends, which are prepared by hot pressing method, with changing thicknesses ranging from 30 to 225 µm, are compared. The spectra, in the wavelength range 200–2500 nm, are examined. Based on optical absorption spectra obtained, Tauc graphs are plotted. Determined values of the direct optical energy gap (E d opt ), the indirect optical energy gap (E i opt ), the width of the band (ΔE), and ultraviolet transmittance (TUV) are listed. The direct E d opt and indirect E i opt values for organic blends are in the range of 3.10–3.17 eV and 1.52–2.99 eV; for inorganic blends they are 1.80–4.13 eV and 1.55–4.7 eV respectively. The electrical strength (ε) and the mechanical tension (σ) have been investigated, and graphs (the dependence of the electrical life time log τε on ε) are given. The experimental results are analyzed from the viewpoint of the validity of the thermofluctuation theory. LDPE and LDPE/0.5% diamond composite parameters consecutively changed: σ from 68 to 82 MPa, ε from 60·106 to 85·106 V/m, mechanical lifetime τσ from 10 to 1.5·105 sec, electrical lifetime τε from 2· 103 to 2·105 sec, and structure-sensitive parameters γ and χ — from 1.48 to 1.18 (J)MPa/mole and from 0.97 to 0.70 (J)Vm−1/mole respectively. The values of mechanical and electrical durability were observed to increase by 20 and 41%, respectively, for LDPE/0.5% diamond composite

Optical and dielectric properties of polypropylene/montmorillonite nanocomposites

“…Simultaneously, E g clearly decreases at a nanoparticle content of 6%. The value of the bandgap in our pure PP is similar to that reported by some authors [21][22][23]. The most probable interpretation of such decrease is that nanoclay particles produce disorder and multiple states in the PP valence band structure leading to the narrowing of the bandgap.…”

Optically Detected X-ray Absorption Spectroscopy Measurements as a Means of Monitoring Corrosion Layers on Copper

“…The cell window used in these experiments was optically transparent “cooking film” made from 10-μm-thick low-density polyethylene (LDPE). For comparison, the mean transmission of 60-μm LDPE with a low impurity level is >93% and decreases by less than 4% across the wavelength range 300 nm−1 μm . This seals easily to the top of the cell, and since the windows adsorb chlorides (for example) from the cell electrolyte during a reduction process, the fact that it is inexpensive and disposable was considered important.…”

“…For comparison, the mean transmission of 60-µm LDPE with a low impurity level is >93% and decreases by less than 4% across the wavelength range 300 nm-1 µm. 19 This seals easily to the top of the cell, and since the windows adsorb chlorides (for example) from the cell electrolyte during a reduction process, the fact that it is inexpensive and disposable was considered important. During spectroelectrochemical analysis, the surface of interest (the working electrode in the cell) is positioned at ∼125 µm from the inside of the window, thus remaining in contact with a layer of electrolyte.…”