scholarly journals LDPE and HDPE Microplastics Differently Affect the Transport of Tetracycline in Saturated Porous Media

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1757
Author(s):  
Enzhu Hu ◽  
Hongbo Yuan ◽  
Yichun Du ◽  
Xijuan Chen
Keyword(s):  
High Density Polyethylene ◽  
Solution Chemistry ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Saturated Porous Media ◽  
Zeta Potentials ◽  
Surface Areas ◽  
Subsurface Environments ◽  
Alkaline Conditions ◽  
Neutral Conditions

The accumulation of microplastics (MPs) in soil and sediments may influence the penetration of contaminants into subsurface environments. However, little attention has been paid to comparing the different roles of two common polyethylene (PE) types—low-density polyethylene (LDPE) and high-density polyethylene (HDPE). In this study, the transport behaviors of tetracycline in saturated quartz sand columns in the presence and absence of these two MPs were investigated, respectively. The results showed that both types of PE MPs restrained the mobility of tetracycline at neutral conditions, while such detrimental effects were weak at acid and alkaline conditions. The degree of nonequilibrium adsorption was higher, and tetracycline transferred easier to the kinetic site for the existence of LDPE than of HDPE. The increased roughness and Brunauer-Emmett-Teller (BET) surface areas, more negative zeta potentials and the formation of oxygen function groups on the surface of MPs after UV-weathering intensified the retardation of tetracycline transport. This study revealed that the PE type and weathering should be taken into account in risk assessment, along with the solution chemistry.

scholarly journals EFFECTIVENESS OF CERTAIN STABILIZERS ON THE AGEING OF POLYETHYLENE FILMS

1998 ◽  
Vol 6 (6) ◽  
pp. 71-76
Author(s):  
S. JIPA ◽  
R. SETNESCU ◽  
T. SETNESCU ◽  
C. PODINA ◽  
J. MIHALCEA
Keyword(s):  
High Density Polyethylene ◽  
High Density ◽  
Low Density Polyethylene ◽  
Phenolic Antioxidants ◽  
Low Density ◽  
Chemiluminescence Method ◽  
Antioxidant Efficiency ◽  
Polyethylene Films

The effectiveness of different phenolic antioxidants on high-density polyethylene (HDPE) and low-density polyethylene (LDPE) has been studied by the Isothermal chemiluminescence method. The decreasing order of the antioxidant efficiency for these polymers Is as follows: lrganox 1010 >> Etanox 330 > lrganox 1076 (Hostanox 016) > Topanol OC

Physicomechanical properties of composites based on various types of polyethylene and aluminum

2020 ◽  
Vol 10 ◽  
pp. 48-55
Author(s):  
H. V. Allakhverdiyeva ◽  
◽  
N. T. Kakhramanov ◽  
I. I. Ismayilov ◽  
◽  
...  
Keyword(s):  
Tensile Stress ◽  
High Density Polyethylene ◽  
Ultimate Tensile Stress ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Aluminum Particles ◽  
Elongation At Break ◽  
Elastic Module ◽  
Properties Of Composites

The paper presents the results of a study of the effect of aluminum content on the physic-mechanical properties of composites based on high density polyethylene and low density polyethylene. The properties of metal-filled composites, such as ultimate tensile stress, elongation at break, elastic module, melt flow rate, and heat resistance, were studied. According to the data obtained, the loading of aluminum into the composition of low density polyethylene contributes to a monotonic increase in the ultimate tensile stress and the elastic module. When aluminum is loading into the composition of high density polyethylene, on the contrary, a natural decrease in the ultimate tensile stress and elongation at break of the composites is observed. It is shown that when using a compatibilizer, which is polyethylene modified with maleic anhydride, a significant increase in the ultimate tensile stress of high-density polyethylene composites is observed. A schematic representation of the structure of composites with an interpretation of the probable mechanism of hardening of the material in the presence of a compatibilizer is given. It is shown that the crystallinity of the initial polyethylene has a significant effect on the hardening effect of composites. Electron microscopic micrographs of the structure of a filled composite without and with compatibilizer are given. A comparative assessment shows that in the presence of a compatibilizer, aluminum particles are in the bulk of the polymer matrix, i.e. are not in an isolated state. It is assumed that HDPE macrochains free of maleic anhydride (MA) are involved in the formation of crystalline formations, and small sections of macrosegments containing polar groups of MA are concentrated mainly in amorphous regions and in defects in crystalline structures in the form of passage chains. The concentration of PEMA macrosegments containing MA in the narrow amorphous space of HDPE favorably affects the increase in the adhesive forces of interaction on the surface of aluminum particles, which affects the preservation of the ultimate tensile stress at a relatively high level over a wide range of aluminum concentrations.

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