Open AccessEffects of polymorphic form and particle size of SiO2fillers on the properties of SiO2–PEEK composites
Author(s) -
Peng Jie Xue,
Shi Lin Liu,
Jian Bian
Publication year - 2021
Publication title -
journal of advanced dielectrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.38
H-Index - 13
eISSN - 2010-135X
pISSN - 2010-1368
DOI - 10.1142/s2010135x21500211
Subject(s) - materials science , composite material , dielectric , composite number , dielectric loss , particle size , thermal expansion , thermal conductivity , particle (ecology) , peek , permittivity , amorphous solid , polymer , crystallography , chemistry , geology , oceanography , optoelectronics
The effects of polymorphic form and particle size of SiO 2 fillers on the dielectric, mechanical and thermal properties of SiO 2 –Polyetheretherketone (SiO 2 –PEEK) composites were investigated in this paper. Strong low frequency (<10Hz) Debye-like dielectric dispersions could be observed for all samples. The dielectric permittivity at high frequencies of the composite exhibits little morphology or particle size-sensitive characteristics of the SiO 2 fillers. All the composites obtained in this case demonstrate the dielectric permittivities of [Formula: see text] at high frequencies. The crystalline [Formula: see text]-cristobalite filled composite exhibits lower dielectric loss and mechanical strength, but larger thermal expansion coefficient and thermal conductivity, compared with the similar particle sized amorphous SiO 2 filled one. The crystalline [Formula: see text]-quartz filled composite demonstrates the lowest mechanical strength and highest dielectric loss. An increase in particle size of the spherical fused silica fillers decreases the dielectric loss, while increases the thermal conductivity of the composite. The flexural strength of the composite reaches the maximum value of 113 MPa when the particle size of spherical SiO 2 filler is [Formula: see text]m. Particle packing by combining optimal amounts of differently sized spherical fused silica fillers leads to a substantial improvement of mechanical strength (153MPa) coupled with reasonable dielectric and thermal properties due to the synergic effect (dielectric permittivity ([Formula: see text] = 3.35, dielectric loss (tan[Formula: see text] @10 GHz, thermal conductivity ([Formula: see text] = 0.74 W/m*k ([Formula: see text]C), coefficient of thermal expansion ([Formula: see text]C and relative density ([Formula: see text]) = 99.72%).