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Thermal, electrical, and mechanical properties of addition‐type liquid silicone rubber co‐filled with Al 2 O 3 particles and BN sheets
Author(s) -
Feng Qikun,
Zhang DongLi,
Zha Junwei,
Yin Lijuan,
Dang Zhimin
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.49399
Subject(s) - materials science , composite material , ultimate tensile strength , silicone rubber , thermal stability , electrical resistivity and conductivity , scanning electron microscope , dielectric , thermal conductivity , shore durometer , dispersion (optics) , permittivity , chemical engineering , physics , electrical engineering , optoelectronics , optics , engineering
The addition‐type liquid silicone rubber (ALSR) co‐filled with spheroidal Al 2 O 3 and flaky BN was prepared by the mechanical blending and hot press methods to enhance the thermal, electrical, and mechanical properties for industrial applications. Morphologies of ALSR composites were observed by scanning electron microscopy (SEM). It was found that the interaction and dispersion state of fillers in the ALSR matrix were improved by the introduction of BN sheets. Thermal, electrical, and mechanical performances of the ALSR composites were also investigated in this work. The result indicated that the thermal conductivity of ALSR can reach 0.64 W m −1 K −1 at the loading of 20 wt% Al 2 O 3 /20 wt% BN, which is 3.76 times higher than that of pure ALSR. The addition of Al 2 O 3 particles and BN sheets also improve the thermal stability of ALSR composites. Moreover, pure ALSR and ALSR composites showed relatively lower dielectric permittivity (1.9–3.1) and dielectric loss factor (<0.001) at the frequency of 10 3 Hz. The insulation properties including volume resistivity and breakdown strength were improved by the introduction of flaky BN in the ALSR matrix. The volume resistivity and characteristic breakdown strength E 0 are 6.68 × 10 15 Ω m and 93 kV/mm, respectively, at the loading of 20 wt% Al 2 O 3 /20 wt% BN. In addition, the mechanical characteristics including elongation at break and tensile strength of ALSR composites were also enhanced by co‐filled fillers. The combination of these improved performances makes the co‐filled ALSR composites attractive in the field of electrical and electronic applications.