Drawing of ultrahigh molecular weight polyethylene fibers in the presence of supercritical carbon dioxide

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 41; no. 12; pp. 1375 - 1383
• Main Authors: Garcia-Leiner, Manuel, Song, John, Lesser, Alan J.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.06.2003; Wiley
• Subjects: Applied sciences; Exact sciences and technology; Fibers and threads; Forms of application and semi-finished materials; mechanical properties; Polymer industry, paints, wood; polymorphism; supercritical carbon dioxide; Technology of polymers; ultrahigh molecular weight polyethylene fibers; Polyethylene; Stretchability; Carbon dioxide; Synthetic fiber; Mechanical properties; Temperature effect; Tensile property; polymorphism; Experimental study; Property processing relationship; Uniaxial drawing; supercritical carbon dioxide; Oriented polymer; ultrahigh molecular weight polyethylene fibers; Supercritical solvent; drawing; Ultrahigh molecular weight ethylene polymer; Crystalline structure
• ISSN: 0887-6266; 1099-0488
• DOI: 10.1002/polb.10474

The drawing behavior of ultrahigh molecular weight polyethylene fibers in supercritical carbon dioxide (scCO2) is compared to that in air at different temperatures. The temperature substantially influences the drawing properties in air, whereas in scCO2, a constant draw stress and tensile strength are observed. Differential scanning calorimetry shows an apparent development of a hexagonal phase along with a significant increase in the crystallinity of air‐drawn samples with increasing temperature. The existence of this phase is not confirmed by wide‐angle X‐ray scattering, which instead shows that air‐drawn samples crystallize in an internally constrained manner. In contrast, scCO2 allows crystals to grow without constraints through a possible crystal–crystal transformation, increasing the processing temperature to 110 °C. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1375–1383, 2003