Oriented polyethylene terephthalate

Table 7. Full Set of Compliances for the Oriented Polyethylene Terephthalate Sheet with Orthorhombic Symmetry...

MC MDI MEKP MF MMA MPEG MPF NBR NDI NR OPET OPP OSA PA PAEK PAI PAN PB PBAN PBI PBN PBS PBT PC PCD PCT PCTFE PE PEC PEG PEI PEK PEN PES PET PF PFA PI PIBI PMDI PMMA PMP PO PP PPA PPC PPO PPS PPSU Methyl cellulose Methylene diphenylene diisocyanate Methyl ethyl ketone peroxide Melamine formaldehyde Methyl methacrylate Polyethylene glycol monomethyl ether Melamine-phenol-formaldehyde Nitrile butyl rubber Naphthalene diisocyanate Natural rubber Oriented polyethylene terephthalate Oriented polypropylene Olefin-modified styrene-acrylonitrile Polyamide Poly(aryl ether-ketone) Poly(amide-imide) Polyacrylonitrile Polybutylene Poly(butadiene-acrylonitrile) Polybenzimidazole Polybutylene naphthalate Poly(butadiene-styrene) Poly(butylene terephthalate) Polycarbonate Polycarbodiimide Poly(cyclohexylene-dimethylene terephthalate) Polychlorotrifluoroethylene Polyethylene Chlorinated polyethylene Poly(ethylene glycol) Poly(ether-imide) Poly(ether-ketone) Polyethylene naphthalate Polyether sulfone Polyethylene terephthalate Phenol-formaldehyde copolymer Perfluoroalkoxy resin Polyimide Poly(isobutylene), Butyl rubber Polymeric methylene diphenylene diisocyanate Poly(methyl methacrylate) Poly(methylpentene) Polyolefins Polypropylene Polyphthalamide Chlorinated polypropylene Poly(phenylene oxide) Poly(phenylene sulfide) Poly(phenylene sulfone)... 

Fig. 47. Some small angle scattering curves obtained during heating and cooling of oriented polyethylene terephthalate...

When an initially isotropic polymer is drawn or extruded to a high deformation ratio under suitable conditions, it develops appreciable anisotropy which is apparent in mechanical tests at all stresses up to and beyond the yield stress. A typical example of the anisotropy of yield observed is shown in Fig. 2 in which the tensile yield stress of oriented polyethylene terephthalate (PET) sheets is shown as a fiinction of the an e 6 between the tensile axis (TA) and the initial draw direction (IDD). This large anisotropy is somewhat similar to that observed in cold-rolled metal sheets, for which theories of anisotropic plasticity were suggestedby Hill, Yoshimura and others. A modification of the theory... 

Fig. 2. The variation of tensile yield stress with 0, the angle between the initial draw direction and the tensile axis. The material is oriented polyethylene terephthalate sheet, draw ratio 5 1. Equation (8) was used to construct the full-line and is a good fit to the available data (after Brown et...

Fig, 5. The tensile and compressive yield stresses of (a) oriented polyethylene terephthalate, (b) oriented polypropylene plotted as a function of extension ratio. The stress axis is parallel to the orientation direction. It is clear that for both materials, only the tensile yield stress is appreciably dependent on degree of orientation. 

Applied Spectroscopy 51, No.3, March 1997, p.346-9 AMPLITUDE SPECTRUM APPROACH IN DYNAMIC FT-IR SPECTROSCOPY OF UNIAXIALLY ORIENTED POLYETHYLENE TEREPHTHALATE FILMS. I. DRAW RATIO DEPENDENCE... 

ASTM D2673 provides a standard specification for oriented polypropylene film, and similarly ASTM D3664 provides a specification for biaxially oriented polyethylene terephthalate film for electrical applications. 

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 ... 

In addition to the discrete reflections from the crystallites, the diffraction pattern of a polymer shows diffuse scattering attributed to amorphous regions. Such polymers are said to be semicrystalline, with the crystalline fraction being controlled by molecular regularity. By comparing the relative amounts of crystalline and amorphous scattering of X-rays the crystallinity has been found to vary from more than 90 per cent for linear polyethylene to about 30 per cent for oriented polyethylene terephthalate. 

Table 7.8 Full set of compliances for an oriented polyethylene terephthalate sheet with orthoihombic symmetry ...

Dhoot et al. (2001) showed that the sorption of n-butane and n-pentane in biaxially oriented polyethylene terephthalate increases with the concentration of these alkanes. Influence of temperature Diffusion phenomena of a molecule in a polymer follow an Arrhenius type activation process (Chiang et al., 2002 Kulkami et al., 2003 Patzlaff et al. 2006). The diffusion rate is a function of temperature according to the equation ... 

Dhoot, S. N., Freeman, B. D., Stewart, M. E., and Hill, A. J. Sorption and transport of linear alkane hydrocarbons in biaxially oriented polyethylene terephthalate. Journal of Polymer Science PartB Polymer Physics, 39, 1160-1172 (2001). 

Oriented Polyethylene Terephthalate Sheet with Orthorhombic Symmetry... 

All nine independent elastic constants have been determined for one-way drawn oriented polyethylene terephthalate sheet. The sheet was prepared by drawing isotropic sheet at constant width. It has been shown that there is then both a high degree of chain orientation in the draw direction and that the (100) crystal planes (which mainly reflect preferential orientation of the terephthalate residues in the chain) are preferentially oriented in the plane of the sheet. This type of orientation has been termed uniplanar axial. From the viewpoint of elastic anisotropy, the sheet possesses three orthogonal planes of symmetry and can be described as possessing orthorhombic symmetry. 

Figure 12.13 Comparison of the effectiveness of the Hill criterion and its modified form with internal stress. (Redrawn with permission from Brown, N., Duckett, R.A. and Ward, I.M. (1968) The yield behaviour of oriented polyethylene terephthalate. Phil. Mag., 18, 483.

Figure 12.33 Curve matching procedure to obtain the network draw ratios for polyester fibres. (Reproduced with permission from Long, S.D. and Ward, I.M. (1991) Shrinkage force studies of oriented polyethylene terephthalate. ]. Appl. Polym. Sci., 42, 1921. Copyright (1991) John Wiley Sons, Inc.)...

Figure 5.200 Behavior of non-oriented polyethylene terephthalate as a function of temperature [773]...

Non-oriented polyethylene terephthalate generally exhibits a sharp transition from ductile to brittle failure. Oriented PET with a planar expansion factor < 2.5 also exhibits this transition, although the transition is less abrupt and becomes wider with increasing planar expansion [773]. 

Wyeth NC, Roseveare RN. Biaxially oriented polyethylene terephthalate bottles. US Patent No. 3,733,309 issued May 15, 1973. 

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