The objectives of this technical note are to review the gas transport mechanisms through flexible geomembranes, and to measure the methane gas transmission rate, permeance, and permeability coefficient of PVC, LLDPE, and HDPE geomembranes by performing the standard gas transport test (ASTM D1434). The measured methane gas permeability coefficient through a PVC geomembrane is 7.55 3 10 ml(STP).m...

Reducing emissions is essential for minimizing the impact of soil fumigation on the environment. Water application to the soil surface (or water seal) has been demonstrated to reduce 1,3-dichloropropene (1,3-D) emissions in soil column tests. This study determined the effectiveness of water application to reduce emissions of 1,3-D and chloropicrin (CP) in comparison to other surface seals under...

In this paper, the implications of melt compatibility on thermal and solid-state properties of linear low density polyethylene/high density polyethylene (LLDPE/HDPE) blends were assessed with respect to the effect of composition distribution (CD) and branch content (BC). The effect of CD was studied by melt blending a metallocene (m-LLDPE) and a Ziegler-Natta (ZN) LLDPE with the same HDPE at 19...

The effect that polymer molecular weight has on the dispersion of relatively polar montmorillonite (MMT) in nonpolar, unmodified high density polyethylene (HDPE) was examined. Polymer layered silicate (PLS) nanocomposites were prepared via melt compounding in a single screw extruder using three unmodified HDPE matrices of differing molecular weight and organically modified MMT (organoclay) in c...

Soil fumigation in greenhouses or agricultural fields often includes tarping the soil surface with polyethylene (PE) films to contain the fumigant in the soil and reduce emissions to the atmosphere. Previous research has demonstrated that PE films are permeable to methyl bromide and other fumigant compounds. In these experiments, the effect of temperature, fumigant mixtures, condensed water, an...

In the process of polyethylene extrusion polymer material similar to powder or granule is under compression, melting and transmission operation and on base of special form, extrudate has been produced. Twin-screw extruders are applicable in industries because of their high capacity. The powder mixing with chemical additives and melting with thermal and mechanical energy in three zones (feed, co...

Using laboratory soil chambers a nonscaled representation of an agricultural raised bed was constructed. For a sandy loam soil, 1,3-dichloropropene (1,3-D) and chloropicrin (CP) were applied at 5 cm depth with an excess of water (simulated drip irrigation). Application was made under both high density polyethylene (HDPE) and virtually impermeable film (VIF) covering the soil bed (the furrow was...

The performance of many consumer products suffers due to weak and inconsistent bonds formed to low surface energy polymer materials, such as polyolefin-based high-density polyethylene (HDPE), with adhesives, such as cyanoacrylate. In this letter, we present an industrially relevant means of increasing bond shear strength and consistency through vacuum metallization of chromium thin films and na...

Under uniaxial tension, high-density polyethylene (HDPE) often fractures in a ductile manner. The fracture involves extensive necking that is known to occur in the plane-stress condition. However, for large-scale HDPE products like polyethylene pipe, crack can grow rapidly in a brittle manner. This type of fracture is known to be in the plane-strain condition, which has much lower toughness tha...

Cell colonization of synthetic polymers can be regulated by physical and chemical modifications of the polymer surface. High-density and low-density polyethylene (HDPE and LDPE) were therefore activated with Ar⁺ plasma and grafted with fibronectin (Fn) or bovine serum albumin (BSA). The water drop contact angle usually decreased on the plasma-treated samples, due to the formation of oxidized gr...