The crystal lamellar morphology of an aromatic polyketone with unusual crystallization and melting behaviour

D. J. Blundell, J. J. Liggat, A. Flory

Research output: Contribution to journalArticle

43 Citations (Scopus)

Abstract

Wide-angle and small-angle X-ray scattering and differential scanning calorimetry are used to elucidate the lamellar morphology of an aromatic polyketone (designated PK99). PK99 has three unusual crystallization and melting characteristics. First, there is a coupled melting and recrystallization process at around 260°C, well below the final melting point of 306°C; this process suggests two crystal forms. Secondly, there are two maxima in the growth rate versus temperature characteristics. Thirdly, the melting point is relatively low compared with the Tg (158°C). WAXS shows that above and below the 260°C process there is no essential difference in the crystal packing. However, WAXS and SAXS data do show small step differences in crystal perfection and in lamellar thickness. The lamellar thicknesses are comparable to the periodic repeat length. This produces a new situation not normally observed in other crystalline polymers, where more than one type of lamellae can be formed containing different chain sequences. The unusual characteristics can be explained in terms of these different types of lamellae.

LanguageEnglish
Pages2475-2482
Number of pages8
JournalPolymer
Volume33
Issue number12
DOIs
Publication statusPublished - 1 Jan 1992

Fingerprint

Crystallization
Melting
Crystals
Melting point
X ray scattering
Differential scanning calorimetry
Polymers
Crystalline materials
Temperature

Keywords

  • aromatic polymer
  • crystal morphology
  • crystallization
  • differential scanning calorimetry
  • melting behaviour
  • polyketone
  • X-ray scattering

Cite this

@article{f852000f0f9f4d6c99685d5235ef1a26,
title = "The crystal lamellar morphology of an aromatic polyketone with unusual crystallization and melting behaviour",
abstract = "Wide-angle and small-angle X-ray scattering and differential scanning calorimetry are used to elucidate the lamellar morphology of an aromatic polyketone (designated PK99). PK99 has three unusual crystallization and melting characteristics. First, there is a coupled melting and recrystallization process at around 260°C, well below the final melting point of 306°C; this process suggests two crystal forms. Secondly, there are two maxima in the growth rate versus temperature characteristics. Thirdly, the melting point is relatively low compared with the Tg (158°C). WAXS shows that above and below the 260°C process there is no essential difference in the crystal packing. However, WAXS and SAXS data do show small step differences in crystal perfection and in lamellar thickness. The lamellar thicknesses are comparable to the periodic repeat length. This produces a new situation not normally observed in other crystalline polymers, where more than one type of lamellae can be formed containing different chain sequences. The unusual characteristics can be explained in terms of these different types of lamellae.",
keywords = "aromatic polymer, crystal morphology, crystallization, differential scanning calorimetry, melting behaviour, polyketone, X-ray scattering",
author = "Blundell, {D. J.} and Liggat, {J. J.} and A. Flory",
year = "1992",
month = "1",
day = "1",
doi = "10.1016/0032-3861(92)91127-N",
language = "English",
volume = "33",
pages = "2475--2482",
journal = "Polymer",
issn = "0032-3861",
number = "12",

}

The crystal lamellar morphology of an aromatic polyketone with unusual crystallization and melting behaviour. / Blundell, D. J.; Liggat, J. J.; Flory, A.

In: Polymer, Vol. 33, No. 12, 01.01.1992, p. 2475-2482.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The crystal lamellar morphology of an aromatic polyketone with unusual crystallization and melting behaviour

AU - Blundell, D. J.

AU - Liggat, J. J.

AU - Flory, A.

PY - 1992/1/1

Y1 - 1992/1/1

N2 - Wide-angle and small-angle X-ray scattering and differential scanning calorimetry are used to elucidate the lamellar morphology of an aromatic polyketone (designated PK99). PK99 has three unusual crystallization and melting characteristics. First, there is a coupled melting and recrystallization process at around 260°C, well below the final melting point of 306°C; this process suggests two crystal forms. Secondly, there are two maxima in the growth rate versus temperature characteristics. Thirdly, the melting point is relatively low compared with the Tg (158°C). WAXS shows that above and below the 260°C process there is no essential difference in the crystal packing. However, WAXS and SAXS data do show small step differences in crystal perfection and in lamellar thickness. The lamellar thicknesses are comparable to the periodic repeat length. This produces a new situation not normally observed in other crystalline polymers, where more than one type of lamellae can be formed containing different chain sequences. The unusual characteristics can be explained in terms of these different types of lamellae.

AB - Wide-angle and small-angle X-ray scattering and differential scanning calorimetry are used to elucidate the lamellar morphology of an aromatic polyketone (designated PK99). PK99 has three unusual crystallization and melting characteristics. First, there is a coupled melting and recrystallization process at around 260°C, well below the final melting point of 306°C; this process suggests two crystal forms. Secondly, there are two maxima in the growth rate versus temperature characteristics. Thirdly, the melting point is relatively low compared with the Tg (158°C). WAXS shows that above and below the 260°C process there is no essential difference in the crystal packing. However, WAXS and SAXS data do show small step differences in crystal perfection and in lamellar thickness. The lamellar thicknesses are comparable to the periodic repeat length. This produces a new situation not normally observed in other crystalline polymers, where more than one type of lamellae can be formed containing different chain sequences. The unusual characteristics can be explained in terms of these different types of lamellae.

KW - aromatic polymer

KW - crystal morphology

KW - crystallization

KW - differential scanning calorimetry

KW - melting behaviour

KW - polyketone

KW - X-ray scattering

UR - http://www.scopus.com/inward/record.url?scp=0001681699&partnerID=8YFLogxK

U2 - 10.1016/0032-3861(92)91127-N

DO - 10.1016/0032-3861(92)91127-N

M3 - Article

VL - 33

SP - 2475

EP - 2482

JO - Polymer

T2 - Polymer

JF - Polymer

SN - 0032-3861

IS - 12

ER -