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Dielectric properties of an epoxy‐amine system at a high microwave frequency
Author(s) -
Zong Liming,
Zhou Shuangjie,
Sgriccia Nikki,
Hawley Martin C.,
Sun Rensheng,
Kempel Leo C.
Publication year - 2005
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.20345
Subject(s) - diglycidyl ether , epoxy , dielectric , materials science , arrhenius equation , curing (chemistry) , relaxation (psychology) , polymer chemistry , polymerization , dipole , bisphenol a , composite material , polymer , thermodynamics , chemistry , activation energy , organic chemistry , psychology , social psychology , physics , optoelectronics
The dielectric properties of a curing diglycidyl ether of bisphenol A (DGEBA)/Jeffamine D‐230 system have been studied over the temperature range of 20–90°C at 2.45 GHz. It was found that, generally, both the dielectric constant and the dielectric loss factor of the system increased with temperature and decreased as the reaction proceeded. The epoxy resins at different extents of cure exhibited the γ relaxation, which can be described by the Arrhenius Rate Law. The relaxation is attributed to the motions of the dipolar groups associated with the reactants. The Davidson‐Cole model can represent the temperature dependencies of the dielectric properties. The nature of the information yielded by dielectrometry on the dynamics of the system is discussed. The evolution of the parameters of the models during the polymerization was mainly affected by the decreasing number of the dipolar groups involved in the reaction and increasing medium viscosity. POLYM. ENG. SCI. 45:1576–1580, 2005. © 2005 Society of Plastics Engineers