Shear Flow-induced Crystallization of Poly(ether ether ketone)

When a semicrystalline polymer melt is subjected to sufficient flow before crystallization, the nucleation rate is accelerated. In this study, the degree of acceleration is investigated with a commercial poly(ether ether ketone), using a rotational rheometer. With a constant shearing time of 1 s, the nucleation rate increases with the shear rate. At a constant shear rate of 20 s-1, the nucleation rate increases with the shearing time. For a constant strain (𝛾 = 300), high shear rates with short shearing times enhance the nucleation rate more than low shear rates with long shearing times. The specific work (𝑊 = 𝜎𝛾 where 𝜎 is the shear stress) reduces all nucleation times to a common curve. A flow-induced nucleation model is suggested based on the entropy reduction model of Flory and the isothermal nucleation model of Hoffman and Lauritzen. A key ingredient is the critical volume of the nucleus, which is found to be 8 – 10 nm3 which corresponds to 3 – 4 Kuhn segments for PEEK.

Files

Metadata

Work Title Shear Flow-induced Crystallization of Poly(ether ether ketone)
Access
Open Access
Creators
  1. Ralph Colby
License Public Domain Mark 1.0
Work Type Article
Publication Date 2020
Publisher Identifier (DOI)
  1. 10.1021/acs.macromol.9b02611
Deposited February 25, 2021 18:15

Analytics

Collections

This resource is currently not in any collection.

Work History

Version 1
published

  • Created
  • Added Creator Ralph Colby
  • Added ShearFIC of PEEK1withSI.pdf
  • Updated License Show Changes
    License
    • http://creativecommons.org/publicdomain/mark/1.0/
  • Published