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A study on the properties of epoxy resin toughened by a liquid crystal‐type oligomer
Author(s) -
Zhang BaoLong,
Tang GuangLiang,
Shi KeYu,
You YingCai,
Du ZongJie,
Huang JiFu
Publication year - 1999
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/(sici)1097-4628(19990103)71:1<177::aid-app20>3.0.co;2-p
Subject(s) - epoxy , curing (chemistry) , materials science , composite material , izod impact strength test , activation energy , toughening , microstructure , oligomer , dynamic mechanical analysis , bisphenol a , modulus , thermosetting polymer , polymer chemistry , ultimate tensile strength , polymer , toughness , chemistry , organic chemistry
A series of novel reactive toughening agents (LCEU PPG ) containing both a flexible spacer and rigid liquid crystalline unit were synthesized to modify the bisphenol epoxy resin/dicyandiamide curing system. The curing reactivity, apparent activation energy, curing mechanism, dynamic mechanical behavior, and impact strength of the modified system were systematically studied. Compared with the unmodified system, the results indicate that LCEU PPG have greatly accelerated the curing reaction between epoxy resin and dicyandiamide, reduced the apparent activation energy of the curing reaction, enhanced the impact strength 3–7 times, and maintained high dynamic modulus and good thermal properties. In addition, SEM observation of the fracture surfaces showed a two‐phase microstructure in the modified systems. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 177–184, 1999