Paper Number
SM31 

Session
Polymers Solutions, Melts and Blends

Title
Shear flow-induced crystallization of poly(ether ether ketone)

Presentation Date and Time
October 23, 2019 (Wednesday) 10:40

Track / Room
Track 3 / Room 201

Authors (Click on name to view author profile)

  1. Seo, Jiho (Penn State University, Materials Science and Engineering)
  2. Gohn, Anne (Penn State Behrend, School of Engineering)
  3. Rhoades, Alicyn (Penn State Behrend, School of Engineering)
  4. Schaake, Richard (SKF, Engineering and Research Centre)
  5. Colby, Ralph (Pennsylvania State University, Materials Science and Engineering)

Author and Affiliation Lines (in printed abstract book)
Jiho Seo1, Anne Gohn2, Alicyn Rhoades2, Richard Schaake3, and Ralph Colby1
1Materials Science and Engineering, Penn State University, University Park, PA 16802; 2School of Engineering, Penn State Behrend, Erie, PA 16563; 3Engineering and Research Centre, SKF, Nieuwegein, The Netherlands

Speaker / Presenter 
Seo, Jiho

Text of Abstract
When a semicrystalline polymer melt is subjected to intense shear flow before crystallization, the crystallization rate is accelerated and the crystalline superstructure is transformed from spherulites into anisotropic structures, referred to as flow-induced crystallization (FIC). In this study, FIC is investigated with a commercial poly(ether ether ketone) under well-defined shearing conditions using a rotational rheometer and X-ray scattering. At a constant shear rate, the nucleation rate increases with the shearing time. As the shearing time is extended, shish-kebab patterns are monitored at lower shear rates. With a constant shearing time, the nucleation rate increases with the shear rate. The combination effects of shear rate and shearing time on the acceleration are investigated in terms of shear strain and specific work. For a constant strain, high shear rates with short shearing times enhance the nucleation rate greater than low shear rates with long shearing times. The specific work reduces all nucleation times, monitored under various shearing conditions, to a common curve. A flow-induced nucleation model is suggested based on the entropy reduction model of Flory.