Scanning electron microscopy fractures

Figure 5.141. A glass fiber reinforced LCP composite is shown to have interesting morphology. A polished thin section is shown in polarized light (A) to exhibit a fine domain texture with some orientation of the polymer on the glass surfaces (see color insert). Scanning electron microscopy fracture views (B-D) show the tenacious adhesion of the LCP to the fibers. Fibrillar structures are oriented parallel to the fiber surface, and submicrometer sized domains are observed (D).

Scanning electron microscopy (thickness topography porosity barrier layers fracture sections) Energy dispersive X-ray analysis (EDX)... 

To ensure quality control material suppliers and developers routinely measure such complex properties as molecular weight and its distribution, crystallinity and crystalline lattice geometry, and detailed fracture characteristics (Chapter 6). They use complex, specialized tests such as gel permeation chromatography (2, 3), wide- and narrow-angle X-ray diffraction, scanning electron microscopy, and high-temperature pressurized solvent reaction tests to develop new polymers and plastics applications. 

FIGURE 12.11 Scanning electron microscopy (SEM) photomicrographs of the tensile fracture surface of the ethylene-propylene-diene monomer (EPDM) rubber-melamine fiber composites. A, before ageing and B, after ageing at 150°C for 48 h. Test specimen is cut in tbe direction parallel to the milling direction. (From Rajeev, R.S., Bhowmick, A.K., De, S.K., Kao, G.J.P., and Bandyopadhyay, S., Polym. Compos., 23, 574, 2002. With permission.)... 

The morphologies of the tensile-fractured as-spun fibers and the flexural-fractured injection molded specimens were studied by scanning electron microscopy (SEM). 

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... 

The micrographs obtained from scanning electron microscopy are shown in Fig. 54 for the tensile fractured surface of 50 CR/50 XNBR self-crosslinked blend filled with 10 phr layered silicate (Fig. 54a) and for the same blend without any... 

Ideally, rubber toughening should be accomplished without substantial sacrifices in modulus. For each modified resin, flexural and Young moduli and plane-strain fracture toughness were determined. Examination of various fracture surfaces by scanning electron microscopy showed the effects of modifier composition on the morphology of these multi-phase materials as well as the prominent features of the fracture process. 

Bond failure may occur at any of the locations indicated in Fig. 1. Visual determination of the locus of failure is possible only if failure has occurred in the relatively thick polymer layer, leaving continuous layers of material on both sides of the fracture. The appearance of a metallic-appearing fracture surface is not definite proof of interfacial failure since the coupling agent, polymer films, or oxide layers may be so thin that they are not detectable visually. Surface-sensitive techniques such as X-ray photoelectron spectroscopy (XPS) and contact angle measurements are appropriate to determine the nature of the failure surfaces scanning electron microscopy (SEM) may also be helpful if the failed surface can be identified. 

Several studies of polymer/silane coupling agent interphases have involved the use of scanning electron microscopy (SEM) [5-7]. For example, Vaughan and Peek [6] have used SEM to examine fracture surfaces to determine the mode of failure of composite materials and to draw conclusions about interfacial interactions of various coupling agents and epoxide and polymer resin systems. 

Various electron microscopy techniques have been used to study the structures of whippable emulsions such as normal and cryo-scanning electron microscopy or transmission electron microscopy using various preparation methods such as freeze fracturing, freeze etching, etc. The literature is quite extensive, and only a few important papers will be discussed in this chapter. 

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