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Effect of SiO 2 on rheology, morphology, thermal, and mechanical properties of high thermal stable epoxy foam
Author(s) -
Chen Keping,
Tian Chunrong,
Lu Ai,
Zhou Qiuming,
Jia Xiaorong,
Wang Jianhua
Publication year - 2014
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.40068
Subject(s) - epoxy , diglycidyl ether , materials science , composite material , glass transition , rheology , dynamic mechanical analysis , curing (chemistry) , bisphenol a , nucleation , morphology (biology) , polymer , chemistry , organic chemistry , biology , genetics
A series of highly thermostable epoxy foams with diglycidyl ether of bisphenol‐A and bisphenol‐S epoxy resin (DGEBA/DGEBS), 4,4′‐diaminodiphenyl sulfone (DDS) as curing agent have been successfully prepared through a two‐step process. Dynamic and steady shear rheological measurements of the DGEBA/DGEBS/DDS reacting mixture are performed. The results indicate all samples present an extremely rapid increase in viscosities after a critical time. The gel time measured by the crossover of tan δ is independent of frequency. The influence of SiO 2 content on morphology, thermal, and mechanical properties of epoxy foams has also been investigated. Due to the heterogeneous nucleation of SiO 2 , the pore morphology with a bimodal size distribution is observed when the content of SiO 2 is above 5 wt %. Dynamic mechanical analysis (DMA) reveals that pure epoxy foam possesses a high glass transition temperature (206°C). The maximum of specific compressive strength can be up to 0.0253 MPa m 3 kg −1 at around 1.0 wt % SiO 2 . © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131 , 40068.