Medium-density polyethylene properties

The mechanical properties of PTFE at room temperature are similar to those of medium-density polyethylene, i.e., relatively soft with high elongation, and remaining useful over a wide range of temperatures, from cryogenic (just above absolute zero) to 260°C (500°F) its recommended upper use temperature.28 Stress-strain curves are strongly affected by the temperature however, even at 260°C (500°F) the tensile strength is about 6.5 MPa (942 psi).29... 

Mechanical properties of the composite materials, 129 Mechanical strength, 81, 83 Medium density polyethylene (MDPE), 55, 67, 68, 363... 

M. Noroozi, S.M. Zebaijad, Effects of multiwall caibon nanotubes on the thermal and mechanical properties of medium density polyethylene matrix nano composites produced by a mechanical milling method. J. Vinyl Add. Tech. 16, 147—152 (2010)... 

Noroozu and Zeboria [57] have measured the effect of multiwalled carbon nanotubes on the mechanical and thermal properties of medium-density polyethylene matrix carbon nanotube nanocomposites. 

The classification of medium density polyethylene films (Table 20) considers the following properties stiffness, optical properties, coefficient of friction, and surface treatment. 

The objective of this work is to evaluate the fracture behavior of a series of commercial Medium Density Polyethylenes by the EWF technique and find correlations between the fracture parameters and the polymer properties (comonomer content, crystallinity, molecular weight and their distribution) for neat and annealed samples. 

Keywords Medium Density Polyethylenes (MDPE), Essential Work of Fracture (EWF), Tensile properties. Thermal... 

As you can see, the chemical formula for PA 11 is very similar to the formula for PA 12. Therefore, it is no surprise that the physical properties are also similar as shown in Table 2.1 have included properties for medium density polyethylene (MDPE) for a comparison and to support earlier comments made about material selection. 

The low vinyl acetate ethylene—vinyl acetate copolymers, ie, those containing 10—40 wt % vinyl acetate, are made by processes similar to those used to make low density polyethylene for which pressures are usually > 103 MPa (15,000 psi). A medium, ie, 45 wt % vinyl acetate copolymer with mbber-like properties is made by solution polymerisation in /-butyl alcohol at 34.5 MPa (5000 psi). The 70—95 wt % vinyl acetate emulsion copolymers are made in emulsion processes under ethylene pressures of 2.07—10.4 MPa (300—1500 psi). 

Of the remaining materials in Table IV, only Viton, neoprene rubber latex,poly(vinyl alcohol), butyl rubber, and butyl-coated nylon exhibited at least a 20-min breakthrough time forl,2 dichloro-ethane permeation to occur. The nitrile rubber latex, cement dipped nitrile rubber, polyethylene (medium density), and surgical rubber latex were all penetrated by 1,2-dichloroethane in less than 3 min and would be of little use in situations requiring the garment to be in constant contact with 1,2-dichloroethane. From the above, butyl rubber or Viton appear to be the best materials to protect the worker against 1,2-dichloroethane, but because of apparent lot-to-lot variations(20) in butyl properties, Viton appears to be the best suited material of these studies to protect the worker from this chemical. 

Blends of LLDPE/PP = 50 50, with or without compatibilizing ethylene-propylene copolymer, EPR, were studied by Dumouhn et al. [1984]. In spite of the expected immiscibihty, the blends showed additivity of properties with good superposition of the stress growth functions in shear and elongation, as well as with the zero deformation rate Trouton ratio, Rj, = 1. In earlier work, blends of medium density PE (MDPE) with small quantities of ultra-high molecular weight polyethylene (UHMWPE) were studied in shear and extension. Again, SH and Rj, = 1 were observed. 

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