Isothermal crystallization of poly(ether ether ketone) with different molecular weights over a wide temperature range. Issue 1 (11th January 2019)

• Record Type: Journal Article
• Authors: Seo, Jiho; Gohn, Anne M.; Dubin, Olivia; Takahashi, Hideaki; Hasegawa, Hirokazu; Sato, Ruri; Rhoades, Alicyn M.; Schaake, Richard P.; Colby, Ralph H.
• Is Part Of: Polymer crystallization. Volume 2:Issue 1(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-01-11
• Subjects: Avrami crystallization model -- equilibrium melting temperature -- glass transition temperature -- Hoffman‐Lauritzen crystallization model -- PEEK; Crystalline polymers -- Periodicals; Crystallization -- Periodicals; Polymers -- Periodicals; 668.9
• DOI: 10.1002/pcr2.10055
• Languages: English
• ISSNs: 2573-7619

Abstract

Abstract : A systematic investigation to determine the importance of molecular weight on the isothermal crystallization kinetics of PEEK across a broad temperature range is presented for three commercial PEEKs (Victrex 150G, 450G, and 650G). The Avrami crystallization model is fit to the isothermal crystallization kinetics of PEEK as a function of crystallization time. To describe the secondary crystallization kinetics, a modified Avrami model is suggested by introducing a second Avrami exponent. The primary and secondary Avrami exponents of PEEK are 3.3 ± 0.4 and 2.3 ± 0.3. Using both standard differential scanning calorimetry (DSC) and fast scanning chip calorimetry (FSC), isothermal PEEK crystallization kinetics are investigated in a wide range of crystallization temperatures (158°C < T c < 336°C). As the molecular weight is increased, the crystallization kinetics decrease. The crystallization half‐times from DSC and FSC are well described by the Hoffman‐Lauritzen model over the entire range of possible crystallization temperatures. Abstract : The molecular weight effect on isothermal crystallization kinetics is systematically investigated with three commercial PEEKs. Crystallization half‐time of Victrex PEEK 150G (black), 450G (red), and 650G (blue) as a function of crystallization temperature (158°C < T c < 336°C) from flash scanning chip calorimetry (FSC open symbols) and standard differential scanning calorimetry (DSC filled symbols) form curves showing the Hoffmann‐Lauritzen crystallization model.