Premium
Effect of structural change of pitch on the thermal conductivity of epoxy‐based composites filled with heat‐treated pitch
Author(s) -
Heo GunYoung,
Park SooJin
Publication year - 2013
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.4453
Subject(s) - materials science , epoxy , composite material , thermal conductivity , diglycidyl ether , curing (chemistry) , composite number , heat deflection temperature , pyrolysis , bisphenol a , izod impact strength test , chemistry , organic chemistry , ultimate tensile strength
Petroleum‐based pitches were used as filler materialsto study the effects of heat‐treatment‐inducedchanges in pitch structure on the thermal conductivity ofepoxy‐based composites. The heat treatment was performed intwo steps: the first involved heating the pitch to 250 °C inorder to remove the low‐molecular‐weight compounds from the pitch, and the second involved heating the pitch to either 430 or 450 °C. There was no significant difference in the curing behavior of the diglycidyl ether of bisphenol A ( DGEBA )/pitch composites, regardless of the heat‐treatment temperature. However, the thermal conductivity of the DGEBA /pitch composites improved with increasing heat‐treatment temperature, and the epoxy composite prepared with pitch heat‐treated at 430 °C exhibited the maximum thermal conductivity. This can be attributed to structural changes in the pitch, such as the distance between adjacent planes ( d ‐spacing), crystallite height ( L c ) and crystallite width ( L a ). Although L c of the pitch increased with increasing heat‐treatment temperature, the d ‐spacings and L a decreased. These results suggest that the heat treatment of the pitch led to a well‐stacked crystalline structure. However, compared with the pitch heat‐treated at 430 °C, that heat‐treated at 450 °C exhibited lower thermal conductivity in the DGEBA /pitch composite because of the low L a , resulting in the loss of basal carbon as a consequence of in situ gasification, and pyrolysis of the low‐molecular‐weight compounds in the pitch. © 2013 Society of Chemical Industry