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Out-of-plane orientation and crystallinity of biaxially stretched polyethylene terephthalate

Published online by Cambridge University Press:  15 May 2014

Sudheer Bandla
Affiliation:
School of Mechanical and Aerospace Engineering, Oklahoma State University, Tulsa, Oklahoma 74106
Masoud Allahkarami
Affiliation:
School of Mechanical and Aerospace Engineering, Oklahoma State University, Tulsa, Oklahoma 74106
Jay C. Hanan*
Affiliation:
School of Mechanical and Aerospace Engineering, Oklahoma State University, Tulsa, Oklahoma 74106
*
a)Author to whom correspondence should be addressed. Electronic mail: [email protected]

Abstract

The dependence of polymer properties on their processing history can be used advantageously. Polyethylene terephthalate (PET), a semi-crystalline polymer, exhibits a microstructure reliant on process and thermal history. PET undergoes strain-induced crystallization, making it sensitive to mechanical stretching. As the level of crystallinity in PET governs its mechanical behavior, it is necessary to quantify the effect of crystallinity and molecular orientation for efficient use. The present research is focused on an approach that will aid in correlating the stretch ratio of PET films to the percent crystallinity and mechanical properties. PET films with different local stretch ratios were obtained through bi-axially stretching injection-molded cylinders of increasing thickness and weight. Percent crystallinity of the PET films with different stretch ratios was measured using X-ray diffraction. Film samples were marked with respect to the stretch directions for measuring their longitudinal (primary stretch direction) and transverse mechanical properties. Local molecular orientation in the form of pole figures was mapped using the (100) plane corresponding to the PET lattice. This will help in linking the physical sample directions and processing to the molecular orientation. Associating the mechanical properties with molecular alignment helps in designing production processes that realize the material's structural potential.

Type
Technical Articles
Copyright
Copyright © International Centre for Diffraction Data 2014 

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References

Bandla, S. and Hanan, J. (2012). “Microstructure and elastic tensile behavior of polyethylene terephthalate-exfoliated graphene nanocomposites,” J. Mater. Sci. 47(2), 876882.CrossRefGoogle Scholar
Bandla, S., Winarski, R., and Hanan, J. (2013). Nanotomography of Polymer Nanocomposite Nanofibers. Imaging Methods for Novel Materials and Challenging Applications, edited by Jin, H., Sciammarella, C., Furlong, C., and Yoshida, S. (Springer, New York), Vol. 3, pp. 193198.Google Scholar
Bashir, Z., Al-Aloush, I., Al-Raqibah, I., and Ibrahim, M. (2000). “Evaluation of three methods for the measurement of crystallinity of pet resins, preforms, and bottles,” Polym. Eng. Sci. (USA) 40(11), 24422455.CrossRefGoogle Scholar
Daubeny, R. D. P., Bunn, C. W., and Brown, C. J. (1954). “The crystal structure of polyethylene terephthalate,” Proc. R. Soc. Lond. A, Math. Phys. Sci. 226(1167), 531542.Google Scholar
Jabarin, S. A. (1992). “Strain-induced crystallization of poly(ethylene terephthalate),” Polym. Eng. Sci. 32(18), 13411349.CrossRefGoogle Scholar
Jog, J. P. (1995). “Crystallization of polyethyleneterephthalate,” J. Macromol. Sci. – Polym. Rev. (USA) 35(3), 531553.CrossRefGoogle Scholar
Johnson, J. E. (1959). “X-ray diffraction studies of the crystallinity in polyethylene terephthalate,” J. Appl. Polym. Sci. 2(5), 205209.CrossRefGoogle Scholar
Lyons, W. J. (1958). “Theoretical values of the dynamic stretch moduli of fiber-forming polymers,” J. Appl. Phys. 29(10), 14291433.CrossRefGoogle Scholar
Mahendrasingam, A., Martin, C., Fuller, W., Blundell, D. J., Oldman, R. J., Harvie, J. L., MacKerron, D. H., Riekel, C. and Engström, P. (1999). “Effect of draw ratio and temperature on the strain-induced crystallization of polyethylene terephthalate at fast draw rates,” Polymer 40(20), 55535565.CrossRefGoogle Scholar
Meijer, H. E. H. and Govaert, L. E. (2005). “Mechanical performance of polymer systems: the relation between structure and properties,” Prog. Polym. Sci. (UK) 30(8–9), 915938.CrossRefGoogle Scholar
Michaeli, W. and Leopold, T. (2010). Modeling the Structural Performance of Stretch-Blow Moulded PET Bottles, ANTEC 2010 (Society of Plastics Engineers, Orlando).Google Scholar
Silberman, A., Omer, M., Ophir, A., and Kenig, S. (1998). The Effect of Stretch and Heat Transfer on the Thermo-Mechanical Properties of PET Bottles. ANTEC 1998 (Society of Plastics Engineers, Atlanta).Google Scholar
Smith, M. R., Cooper, S. J., Winter, D. J., and Everall, N. (2006). “Detailed mapping of biaxial orientation in polyethylene terephthalate bottles using polarised attenuated total reflection FTIR spectroscopy,” Polymer 47(15), 56915700.CrossRefGoogle Scholar
Thompson, A. B. (1959). “Strain-induced crystallization in polyethylene terephthalate,” J. Polym. Sci. 34(127), 741760.CrossRefGoogle Scholar
Viswanathan, A., Wiff, D. R., and Adams, W. W. (1976). An Investigation of Structure-Property Correlation in Polyethylene Terephthalate Films, Air Force Materials Laboratory, 127.Google Scholar