Effect of network structure on thermal and mechanical properties of cured epoxy resin containing mesogenic group

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370900

Ochi, M; Shimizu, Y; Tsuyuno, N ^[1]

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1. Kansai Univ., Osaka (Japan); and others

Epoxy resin containing biphenol group as a mesogenic group was cured with phenol (PN) and catechol (CN) novolacs. In the CN-cured biphenol type epoxy resin, the glass-rubber transition, almost disappeared and thus the very high elastic modulus was obtained in the high temperature region. It is clear that the micro-Brownian motion of the network chains is highly suppressed in this cured system. On the other hand, the PN-cured resin showed the well-defined glass-rubber transition and thus the low rubbery modulus. In addition, in the former system, the characteristic pattern like a schlieren texture was clearly observed in the polarized optical microphotographs. This shows that the mesogenic group contained in the epoxy molecule is oriented in the system cued with catechol novolac, which has neighboring active hydrogens. The computer simulation based on the molecular mechanics also showed that the orientation of the network chains should occur in the CN-cured biphenol epoxy system. Thus, we conclude that the suppression of the micro-Brownian motion in the CN-cured system is due to the orientation of network chains containing a mesogenic group. Moreover, it has been shown that die mechanical and bonding strength at high temperature is considerably improved by the suppression of the network chain in the CN-cured biphenol resin system.

• OSTI ID: 370900
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BROWNIAN MOVEMENT
CURING
EPOXIDES
MECHANICAL PROPERTIES
PHENOL
RESINS
TEXTURE