Polyethylene microscopy

Annis B K, Noid D W, Sumpter B G, Reffner J R and Wunderlich B 1992 Application of atomic force microscopy (AFM) to a block copolymer and an extended chain polyethylene Makromol. Chem., Rapid. Commun. 13 169 Annis B K, Schwark D W, Reffner J R, Thomas E L and Wunderlich B 1992 Determination of surface morphology of diblock copolymers of styrene and butadiene by atomic force microscopy Makromol. Chem. 193 2589... 

LDM light depolarization microscopy Mylar polyethylene glycol... 

Pandey et al. have used ultrasonic velocity measurement to study compatibility of EPDM and acrylonitrile-butadiene rubber (NBR) blends at various blend ratios and in the presence of compa-tibilizers, namely chloro-sulfonated polyethylene (CSM) and chlorinated polyethylene (CM) [22]. They used an ultrasonic interferometer to measure sound velocity in solutions of the mbbers and then-blends. A plot of ultrasonic velocity versus composition of the blends is given in Eigure 11.1. Whereas the solution of the neat blends exhibits a wavy curve (with rise and fall), the curves for blends with compatibihzers (CSM and CM) are hnear. They resemble the curves for free energy change versus composition, where sinusoidal curves in the middle represent immiscibility and upper and lower curves stand for miscibihty. Similar curves are obtained for solutions containing 2 and 5 wt% of the blends. These results were confirmed by measurements with atomic force microscopy (AEM) and dynamic mechanical analysis as shown in Eigures 11.2 and 11.3. Substantial earher work on binary and ternary blends, particularly using EPDM and nitrile mbber, has been reported. 

Magonov, S.N., Yerina, N.A., Godovsky, Y.K., and Reneker, D.H., Annealing and recrystallization of single crystals of polyethylene on graphite An atomic force microscopy study, J. Macromol. Sci. Part B Phys., 45, 169, 2006. 

Figure 9.22. Scanning force microscopy images of polyethylene films formed on a model planar chromium polymerization catalyst. The small white stripes are lamellar crystals. These form the well-known spherulite superstructure upon crystallization from the...

In their efforts to construct stimuli-responsive, supramolecular amphiphiles, Frechet et al. [126-129] reported the synthesis of a novel series of AB and ABA block copolymers via the Williamson ether synthesis (e.g., 47, Fig. 21). Polyethylene glycols (PEGs) of different lengths were used as the linear hydrophilic B block while polyaryl ether dendrons of different sizes were used as the hydro-phobic A block. These copolymers were characterized by optical microscopy,... 

Figure 5 Electron micrograph of a portion of melt crystallised polyethylene spherulite by transmission electron microscopy (TEM) showing lamellae. Reproduced from Ref. [3] with permission of John Wiley Sons, Inc.

AFM Atomic force microscopy aPP Atactic polypropylene DSC Differential scanning calorimetry HDPE High-density polyethylene iPP Isotactic polypropylene LLDPE Linear low-density polyethylene MD Microdomain ODT Order-disorder transition PB Poly(butadiene)... 

IPHC, Intraperitoneal hyperthermic chemoperfusion/chemotherapy MMC, Mitomycin C IP, Intraperitoneal SOD, Superoxide dismutase Nd YAG, Neodymium-doped yttrium aluminium garnet Nd Y3A15012 NIR, Near infrared FITC, Fluorescein isothiocyanate PEG, Polyethylene glycol FA, Fohc acid CDDP, Cisplatin TEM, Transmission electron microscopy... 

Atomic force microscopy and attenuated total reflection infrared spectroscopy were used to study the changes occurring in the micromorphology of a single strut of flexible polyurethane foam. A mathematical model of the deformation and orientation in the rubbery phase, but which takes account of the harder domains, is presented which may be successfully used to predict the shapes of the stress-strain curves for solid polyurethane elastomers with different hard phase contents. It may also be used for low density polyethylene at different temperatures. Yield and rubber crosslink density are given as explanations of departure from ideal elastic behaviour. 17 refs. 

A chemical blowing agent was well dispersed in a linear low density polyethylene matrix, in pellet form. The pellets were rotationally moulded to produce foams, the morphology of the foams being studied using optical microscopy. The quality of the cell structures in terms of cell size, cell population density and volume expansion ratio was superior to that of foams produced by drying blending. 28 refs. 

Crosslinked low-density polyethylene foams with a closedcell structure were investigated using differential scanning calorimetry, scanning electron microscopy, density, and thermal expansion measurements. At room temperature, the coefficient of thermal expansion decreased as the density increased. This was attributed to the influence of gas expansion within the cells. At a given material density, the expansion increased as the cell size became smaller. At higher temperatures, the relationship between thermal expansion and density was more complex, due to physical transitions in the matrix polymer. Materials with high density and thick cell walls were concluded to be the best for low expansion applications. 16 refs. 

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... 

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