Premium
Biphenyl liquid crystal epoxy containing flexible chain: Synthesis and thermal properties
Author(s) -
Zhang Qian,
Chen Guokang,
Wu Kun,
Shi Jun,
Liang Liyan,
Lu Mangeng
Publication year - 2020
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.49143
Subject(s) - epoxy , materials science , diglycidyl ether , curing (chemistry) , biphenyl , composite material , thermal conductivity , composite number , monomer , thermal stability , bisphenol a , chemical engineering , polymer , organic chemistry , chemistry , engineering
A biphenyl type liquid crystal epoxy (LCE) monomer 4,4′‐di(2,3‐epoxyhexyloxy)biphenyl (LCBP4) containing flexible chain was synthesized and the curing behavior was investigated using 4,4′‐diaminodiphenylmethane (DDM) as the curing agent. The effect of curing condition on the formation of the liquid crystalline phase was examined. The cured samples show good mechanical properties and thermal stabilities. Moreover, the relationship between thermal conductivity and structure of liquid crystalline domain was also discussed. The samples show high thermal conductivity up to 0.28–0.31 W/(m*K), which is 1.5 times as high as that of conventional epoxy systems. In addition, thermal conductive filler, Al 2 O 3 , was introduced into LCBP4/DDM to obtain higher thermal conductive composites. When the content of Al 2 O 3 was 80 wt%, the thermal conductivity of the composite reached to 1.86 W/(m*K), while that of diglycidyl ether of bisphenol A (Bis‐A) epoxy resin/DDM/Al 2 O 3 was 1.15 W/(m*K). Compared with Bis‐A epoxy resin, the formation of liquid crystal domains in the cured LCE resin enhanced the thermal conductivity synergistically with the presence of Al 2 O 3 . Furthermore, the introduction of Al 2 O 3 also slightly increased the thermal stabilities of the cured LCE.