Wide-angle X-ray diffraction and

Wide-angle X-ray diffraction and electron microscopy provide evidence for two modes of slip within PTFE crystals and the progressive breakup and... 

G. Z. Papageorgiou, G. P. Karayannidis, D. N. Bikiaris, A. Stergiou, G. Lit-sardakis, and S. S. Makridis. Wide-angle x-ray diffraction and differential scanning calorimetry study of the crystallization of poly(ethylene naphthalate), poly(butylene naphthalate), and their copolymers. J. Polym. ScL, Part B Polym. Phys., 42(5) 843-860, March 2004. 

The methods for the molecular characterisation by C NMR-spectroscopy, the detection of crystallinity by wide angle X-ray diffraction and the registration of thermal transitions in the heat flow calorimeter were described. ... 

We have already discussed to some extent the type of information which can be obtained from wide angle X-ray diffraction and infra-red spectroscopy concerning orientation in polymers. We now wish to consider in detail the knowledge which can be gained concerning the orientation distribution function p fi,4>,yf). This involves consideration of the way in which different properties reflect orientation. 

From eqn. (14), if one can specify the values of A°n. A/if and one of the orientation functions,/ then the other may be determined by measuring A it. This procedure has been used for semi-crystalline systems where X-ray diffraction is used to determine/r, of all crystalline axes. Thus one can determine/ . a quantity which, in general, is not easy to obtain from two-component systems. The results plotted in Fig. 7 are an example of the data obtained by combining both wide-angle X-ray diffraction and birefringence to uniaxially drawn low density polyethylene. It is clear... 

Papageorgiou GZ, Karayannidis GP, Bikiaris DN, Stergiou A, Litsardakis G, Makridis SS, et al. Wide-angle x-ray diffraction and differential scanning calorimetry study of the crystallization of poly(ethylene naphthalate). 

There are several indirect methods that also yield values of AH . They all require the determination of the enthalpy of fusion as well as the degree of crystallinity of the system. The degree of crystallinity can be obtained by different experimental techniques such as infra-red, wide-angle x-ray diffraction and density measurement among others. Quite often the enthalpy of fusion is measured as a fiinction of density and the data extrapolated to the value of the unit cell to yield AH . The directly measured enthalpy of fusion, as well as the methods used to determine the crystallinity level, are dependent on morphological and structural detail. Moreover, all of the methods usually have different sensitivities to the phase structures. In our... 

One of the authors reported decreases in J-spacing (13) and Ch (12) of PTMSP membranes upon aging. Upon aging, based on density measurements, wide-angle X-ray diffraction, and positron annihilation lifetime spectroscopy studies, YampoFskii and co-workers also inferred a decrease in the free volume of PTMSP(75). 

C. Huang, K.T. Wikfeldt, D. Nordlund, U. Bergmann, T. McQueen, J. Sellberg, L.G.M. Pettersson, A. Nilsson, Wide-angle X-ray diffraction and molecular dynamics study of medium-range order in ambient and hot water. Phys. Chem. Chem. Phys. 13(44),... 

P. H. Hermans and co-workers described how the orientation factor /h may be computed from wide-angle x-ray diffraction, and developed a simple theory of birefringence (45-47). Orientation measured by x-rays and by birefringence were distinguished (46). The former represents the orientation of the crystalline regions and the latter the total orientation, including amorphous regions ... 

Polymer chain orientation factors are most conveniently obtained by a combination of wide-angle x-ray diffraction and optical birefringence measurements on... 

In this study we investigated the crystallization of iPP molded articles with WAXD (wide angle X-ray diffraction) and optical microscopy. Results show that crystallinity of close to the gate is higher than that at other positions. Results also reveal the skin-core stmcture, we can see the thickness of skin layer is thinner with the higher injection temperature. 

Wide angle x-ray diffraction and pole figure analysis... 

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