Polyethylene particles

During the rinse cycle, polyethylene particles float to the surface of the water bath. The higher density PET and PVC particles sink to the bottom of... 

Fig. 3. SEM image of polyethylene particles (a) with homogeneous catalyst (b) with embedded...

The release occurred in the polyethylene product takeoff system, as illustrated in Figure 1-12. Usually the polyethylene particles (product) settle in the settling leg and are removed through the product takeoff valve. Occasionally, the product plugs the settling leg, and the plug... 

Polyethylene particle growth, over Ziegler-Natta catalysts, 26 530-531 Polyethylene polymer properties, control of, 17 703... 

Patent Number US 5459169 A 19951017 UNCROSSLINKED POLYETHYLENE PARTICLES FOR THE PRODUCTION OF EXPANDED PARTICLES AND UNCROSSLINKED POLYETHYLENE EXPANDED PARTICLES Tokoro H Tsurugai K Sasaki H Oikawa M JSP Corp. 

Figure 13.3.5 shows typical SEM photographs of the silica-coated polyethylene particles prepared by dry impact blending utilizing mechanochemical treatment and pollen grain of Clintonia udensis. 

Figure 13.3.7 shows scanning electron microscopy (SEM) photographs of the surface of the polyethylene particle after the silica particles were peeled off. The specimen was prepared in the following way. After the composite particles were potted in epoxy resin, the dried resin block was cut using a microtome to produce fine sections. The fracture surface appearance of the polyethylene was then observed under a microscope. The mean depth penetration into the surface of the core particles could be measured using the SEM photographs. Silica 0.3 pan in diameter was embedded in the surface of the polyethylene particles at a depth of 0.03 xm. In... 

J.B. Matthews, T.R. Green, M.H. Stone, B.M. Wroblewski, J. Fisher, and E. Ingham, Comparison of the response of primary human peripheral blood mononuclear phagocytes from different donors to challenge with model polyethylene particles of known size and dose, Biomaterials, 21(20) 2033-2044, 2000. 

Example 2.2 Consider an impact between a polyethylene particle (dp = 1 cm) and a copper wall. The incident velocity is 2 m/s, and the incident angle is 30°. The friction coefficient of the interface is 0.2. The densities of polyethylene and copper are 950 and 8,900 kg/m3, respectively. What is the contact time duration for the collision Estimate the rebound velocity of the particle. Repeat the problem for a copper particle colliding with a polyethylene wall. 

For a polyethylene particle hitting a copper wall, we have... 

Example 2.3 For a normal impact between a polyethylene particle (dp = 1 cm) and a copper wall, estimate the critical normal collision velocity of the particle, above which plastic deformation would occur. The yield strength for polyethylene is 2 x 107 N/m2 and the yield strength for copper is 2.5 x 108 N/m2. What would be the critical normal collision velocity for a copper sphere colliding with the copper wall ... 

Solution Since the yield strength for polyethylene is lower than that for copper, the polyethylene particle will undergo plastic deformation before the copper wall does in the collision. As obtained in Example 2.2, we have... 

Ethylene is dissolved in isobutane. This ethylene reacts with itself to form polyethylene particles that gradually settle out of solution and are collected in one of six settling legs. Particles pass through a main 8-inch (21 cm) block valve called a DEMCO valve to collect in a chamber. The particles are periodically isolated from the reactor, the volatiles are removed, and the polyethylene is routed to other equipment for further processing. See Figure 5—7, which appeared in OSHA Reports and has been reproduced with the permission of OSHA. 

Though polymers made specifically for high voltage insulation are remarkably clean, occasional contaminants occur and contribute to the deterioration of dielectric properties. Some of these are polymeric in nature such as gels or prematurely corsslinked polyethylene particles which may appear amber to dark brown in color depending on heat history. Figure 5 shows one... 

The same group also reported a disperse system consisting of N-oxyl-immobilized polyethylene particles as disperse phase and aqueous NaHC03-NaBr as disperse medium [19]. N-Oxyl-immobilized poly(p-phenylenebenzobisthiazolc) network polymer particles (PBZTNT-N-oxyl) have also been developed. The polymer is effective for the anodic oxidation of alcohols to afford the corresponding ketones, aldehydes, and/ or carboxylic adds [20]. These achievements nicely demonstrate the potential of liquid-solid disperse systems for eledroorganic synthesis. 

D.J., Marchand, R., and Yahia, L. (1998) Flow cytometric analysis of macrophage response to ceramic and polyethylene particles effects of size, concentration, and composition. J. Biomed. Mater. Res., 41 (4), 600 -607. 

Some results, however, may be restricted to the special conditions of polyethylene particle co-deposition with copper. For example, deposition at other metals like Zn occurs at potentials that are far more negative from the potential of zero charge. In this case no minimum of the hydration force can be expected. Nevertheless, a maximum was observed in the particle concentration versus current density plot. ... 

SEM images of NE+-exchanged mica, dried at 200°C (a), and a polyethylene particle obtained using this clay after its reaction with an a-diimine ligand (b), (c), showing morphology replication. (Reproduced from Fujii, K. et al, Catal. Commun., 10,183,2008. With permission from Elsevier B.V.)... 

Piimax, Surface-treated polyethylene particles. Air Products and Chemicals... 

Figure 3.12 Morphology of a polyethylene particle made with (a) Cp2ZrCl2/Na+ MMT and (b) Cp2ZrCl2/Cloisite 93A (reproduced from Ref. [62]).

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