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Crystallization of poly(etheretherketone) (PEEK) in carbon fiber composites
Author(s) -
Lee Youngchul,
Porter Roger S.
Publication year - 1986
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760260909
Subject(s) - peek , materials science , composite material , crystallization , nucleation , fiber , supercooling , ultimate tensile strength , adhesion , polymer , chemical engineering , chemistry , physics , organic chemistry , thermodynamics , engineering
The tendency of carbon fiber to nucleate the zation of poly(etherettterlcetone) (PEEK) has been evaluated by DSC and other techniques. As the carbon fiber content was increased, the supercooling necessary for PEEK crystallization decreased. The repeated melting (at 396°C) of the same PEEK sample results in a decrease of the number of nuclei for crystallization. At equivalent thermal histories, PEEK with carbon fiber was found to have a higher nucleation density than PEEK itself. The surface of carbon fibers and nuclei in the PEEK matrix compete for crystallization growth. As the holding time in melt was increased, the number of matrix spherulites formed on cooling decreased, hence a more pronounced transcrystalline region was developed. Correspondingly, the composites preheated in the melt for 100 min showed about two times the transverse tensile strength and strain‐to‐failure of those preheated for only 30 min. Corresponding fracture surface produced in tension showed that the former samples had a greater matrix adhesion to the carbon fiber than the latter. A strong interfacial bond is thus developed by crystallization on carbon fiber surface. Destroying nuclei in the PEEK matrix by long preheating enhances crystallization on the carbon fiber.