Polyethylene highly oriented

Fig. 4. Raman spectra of a highly oriented polyethylene fibre. The meaning of the three experiments, shown here is evident from Ref. 10. Full line and broken line indicate electric vector of the laser beam perpendicular and parallel to the fibre axis, respectively. "Sp" spurious emission from the laser...

Fig. 3. Apparent secant modulus (stress/strain) in tension at 0.1% strain and at various sample aspect ratios, measured at strain rate of 10 V. Highly oriented polyethylene (D. R. 28) measured in direction of drawing. (Sample cross section 0.2 mm x 2 mm)...

Fig. 46. Tensile strength of highly oriented polyethylene at Young s modulus = 50 GPa versus weight average molecular weight for various polydispersities (indicated in graph). With permission of the publishers John Wiley Sons. Inc. (C)...

The melting behaviour of the highly oriented polyethylenes was found to... 

Measurements of the permeability and diffusivity have been undertaken for helium and oxygen for a range of highly oriented polyethylene films The deduced solubilities for both gases are proportional to the amorphous volume fraction showing that the non-crystalline regions are the transport medium in all instances. The solubility obtained for oxygen is about ten times that for helium. This result is consistent with the proposal of Michaels and Bixler which relates the amorphous phase... 

The reason for the lower experimental value lies, of course, in the facts that not all chain segments are parallel to the direction of alignment and that the average number of chains crossing unit area normal to the alignment direction is less than the theoretical number. In the next section models for highly oriented polyethylene are described. A model that has been found particularly useful for understanding the moduli of oriented LCPs is considered in section 12.4.7. 

Y. Bin, K. Mayuna, Z. Dan Zhu, M. Masaru, Development of highly oriented polyethylene filled with aligned carbon nanotubes by gelation/crystallization from solutions. Macromolecules... 

Fkj. 2. Derivative wide line NMR signal (dx"ldHo) for highly oriented polyethylene at — 196 C, steady magnetic field Ho along fibre axis (Smith, J. B. Manuel, A, J. and Ward, /. M., unpublished). 

Smith P, Lemstra PJ, Pijpers JPL. Tensile strength of highly oriented polyethylene. II Effect of molecular weight distribution. J Polymer Sci Polym Phys Ed 1982 20 (12) 2229-2241. Stevens PS. Polymer Chemistry An Introduction. 3rd ed. New York Oxford Press 1999. p 234—235. Strobl GR. The Physics of Polymers Concepts for Understanding Their Structures and Behavior. Heidelberg Springer 2007. 

Smith P, Lemstra PJ, Pijpers JPL. Tensile strength of highly oriented polyethylene. B effect of molecular weight distribution. J Polym Sci Polym Phys Ed 1982 20 2229-2241. 

Fig. 8. 15 MHz CP/DD C NMR spectra of highly oriented polyethylene films at 70 and 100°C. The drawing direction is parallel to Bo.

The majority of results so far available in this Held have been derived from spectra recorded on dispersive instruments. In order to test tl validity of Eq. (1) several independent experiments have been performed in which a highly oriented polyethylene terephthalate film is subjected stepwise to increasingly higher stresses in the stretching machine illustrated in Fig. 1 and FTIR spectra are taken at the relaxed stress levels with unpolarized radiation. In Fig. 4 the wavenumber shifts of the v(0—CH2) absorption band are plotted as a fimctimi of the applied stress for different experiments. From these systematic investigations, however, no linear relationship between the wavenumber shift Av and the plied stress good index of determination (0.98) was obtained for the power function ... 

Fig. 3.5 Electron diffraction patterns from (A) amorphous carbon, (B) oriented amorphous polystyrene (tensile direction indicated by arrows) and (C) a polycrystalline PE film. The sharpness of the rings in (C) indicates crystalline order. Highly oriented polyethylene is shown in the diffraction pattern (D) (tensile direction indicated by arrows). The off-axis spots prove the presence of three dimensional order.

Fig. 8.12 Plot of L JLo at 140 °C against square root of radiation dose for highly oriented polyethylene fibers. A / Co gamma irradiation A, irradiation by high-energy electrons.(55)...

The results described above all refer to Raman measurements made prior to the introduction of FT methods and near-infrared sources. More recent work shows that anisotropic measurements are far easier than they were, and can be made at room temp>erature on heated or cooled specimens with consummate ease. The measurements on highly oriented polyethylene shown in Figure 7.7 are simple to produce both at room temperature and at — 180°C. An analysis is available [16]. 

Figure 9.17 Parameter x in Equation (9.22) as a function of the taper draw ratio t to the 3/2 power. (Reproduced from Barham, P.j. and Arridge, R.C.C. (1977) A fiber composite model of highly oriented polyethylene. J. Polym. Sci. Polym. Phys., 15, 1177. Copyright (1977).)...

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