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Rheological characterization of room temperature vulcanized silicone sealant: Effect of filler particle size
Author(s) -
Xu Xiaoming,
Gao Chuanhua,
Zheng Qiang
Publication year - 2008
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.20992
Subject(s) - materials science , rheology , composite material , viscoelasticity , shear rate , particle size , dynamic mechanical analysis , creep , vulcanization , shear modulus , particle (ecology) , sealant , polymer , natural rubber , chemical engineering , oceanography , engineering , geology
Abstract The rheological properties of silicone sealant filled with different calcium carbonate (CaCO 3 ) particles varying in size were investigated. It is found that as particle size decreases, the dynamic storage modulus ( G ′) and shear viscosity (η) increase; whereas, the width of linear viscoelastic region decreases. At low shear rate, a modulus plateau appears and the shear thinning behavior becomes apparent. The reasons for these can be ascribed to the enhanced particle–particle interaction and formation of filler network structure. Moreover, results dealing with the buildup of network structure monitored by kinetic recovery experiments reveal that both the rate of recovery and magnitude of rheological parameters increase with decreasing particle size. This phenomenon is consistent with the data collected from creep and recovery measurements, indicating an enhanced elasticity and network structure. Furthermore, transmission electron microscopy (TEM) observation and mechanical properties tests for cured sealant samples were also carried out to provide an evidence for the discussion further. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers