Paper Number
PO65 

Session
Poster Session

Title
Extensional rheology and final morphology of LDPE fibers

Presentation Date and Time
February 15, 2017 (Wednesday) 6:00

Track / Room
Poster Session / Foyer-Stairs/Windows

Authors (Click on name to view author profile)

1. Wingstrand, Sara L. (Technical University of Denmark)
2. van Drongelen, Martin (Technical University of Denmark)
3. Mortensen, Kell (University of Copenhagen)
4. Graham, Richard S. (University of Nottingham)
5. Huang, Qian (Technical University of Denmark, Department of Chemical and Biochemical Engineering)
6. Hassager, Ole (Technical University of Denmark)

Author and Affiliation Lines (in printed abstract book)
Sara L. Wingstrand¹, Martin van Drongelen¹, Kell Mortensen², Richard S. Graham³, Qian Huang¹, and Ole Hassager^1
1Department of Chemical and Biochemical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark; ²University of Copenhagen, København Ø, Denmark; ³University of Nottingham, Nottingham, United Kingdom

Speaker / Presenter 
Wingstrand, Sara L.

Text of Abstract
Properties of polymeric fibers are highly dependent on the molecular conformation induced during processing[1]. In this study we investigate the influence of non-linear extensional flow on the molecular conformation of branched semi-crystalline polymers. Such materials show a stress overshoot when stretched at a constant extensional rate[2]. The common explanation is, that at first the backbone stretches until the stress maximum is reached. This is followed by a collapse of the branches causing backbone retraction and thus the decrease in stress[3]. Consequently, one would expect the greatest molecular orientation in fibers quenched at the stress maximum. Indeed we find that this is true and also a more general observation that the final orientation scales with stress at quench in the melt.

[1] Schrauwen B. et al, Macromol. 37 (23), 8618 (2004). [2] Rasmussen, H.K. et al. J. Rheol. 49 (2), 369 (2005). [3] Hawke, L.G.D. et al., J. Rheol. 59 (4), 995 (2015).