Microstructure and mechanical properties of quasi-carbon fibers and their polyacrylonitrile matrix composites

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:45040

Zhao, L R; Jang, B Z ^[1]

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1. Auburn Univ., AL (United States)

Quasi-carbon fibers (QCFs) were prepared from Polyacrylonitrile (PAN) precursor by pyrolysis in the temperature range from 400{degrees}C to 950{degrees}C. The QCF-reinforced composites were fabricated by impregnating the QCFs with the PAN resin. The microstructural changes of both QCFs and their composites were characterized by the X-ray diffraction method. The stacking size and the crystallinity of the QCFs increased with the increasing heat treatment temperature (HTT). The crystallinity of the PAN matrix in a composite was also affected by various QCFs. DSC data indicated that thermal reaction mechanism of the composite could be altered due to the interaction between the fiber and the matrix. DMTA studies showed that good adhesion existed at the interface of the QCF-reinforced composites containing lower HTT fibers. The modulus magnitudes of QCFs and their composites increased with the QCF pyrolysis temperature. Although the QCFs exhibited a decreasing trend in strength up to a pyrolysis temperature 650{degrees}C, the strength of the resulting composites increased monotonically. Thus, the QCF-reinforced composites exhibited good mechanical properties despite the fact that a catastrophic failure mode was observed with the QCF that was heat-treated above 650{degrees}C.

• OSTI ID: 45040
• Report Number(s): CONF-941005--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACRYLONITRILE
ADHESION
CARBON FIBERS
CHEMICAL PREPARATION
COMPOSITE MATERIALS
HEAT TREATMENTS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PYROLYSIS
REINFORCED MATERIALS
TENSILE PROPERTIES
X-RAY DIFFRACTION