Abstract
Three grades of functional polypropylene (FPP)/silica (SiO2) (FPPASP16xSiO2y, FPPASP17xSiO2y and FPPASP18xSiO2y) and their crosslinked FPP/SiO2 (CLFPPASP16xSiO2y, CLFPPASP17xSiO2y and CLFPPASP18xSiO2y) nanocomposites were satisfactorily made for applying as fifth generation (5 G) mobile communication substrates. Significantly smaller linear thermal expansion coefficient (LCTE) but larger dielectric constant (εr), dielectric loss (tan δ) and onset degradation temperature (DTonset) were acquired for CLFPPaxSiO2y than those of the corresponding FPPaxSiO2y sequence having identical SiO2 loadings. It is worth emphasizing that substantially smaller εr, tan δ and LCTE values were acquired for every FPPaxSiO2y and CLFPPaxSiO2y sequence filled with appropriate SiO2 loadings. Quite small εr/tan δ ( 2.41/0.00539, 2.36/0.00361, 2.53/0.00653, 2.52/0.00671, 2.46/0.00461 and 2.62/0.00821, all measured at 1 MHz) and LCTE (∼140 ppm/°C, 152 ppm/°C, 75 ppm/°C, 127 ppm/°C, 142 ppm/°C and 56 ppm/°C) values suitable for 5 G communication were acquired for FPPASP1695SiO25, FPPASP1794SiO26, FPPASP1895SiO25, CLFPPASP1695SiO25, CLFPPASP1794SiO26 and CLFPPASP1895SiO25 filled with optimum loadings of SiO2 nanoparticles, respectively. All free volume properties estimated for every FPPaxSiO2y and CLFPPaxSiO2y sequence enlarged to a largest value as the SiO2 loadings approached the corresponding optimum value. Possible reasons accounting for these substantially diminished dielectric and LCTE and improved thermal degradation properties of the FPPaxSiO2y and CLFPPaxSiO2y films are proposed.
Disclosure statement
No potential conflict of interest was reported by the authors.