การปรับปรุงสมบัติเฟียโซอิเล็กทริกของวัสดุผสมเฟียโซอิเล็กทริกที่มียางธรรมชาติเป็นเนื้อพื้น

Abstract

This work aims to study the improvement of piezoelectric properties of piezoelectric composite materials with natural rubber (NR) as a matrix phase and 100 phr lead magnesium niobate titanate doped with zinc oxide (PMNT) in the forms of ceramic powder (NR/100PMNT) and bulk as dispersed phases. Different amounts (15, 20, 25 and 30 phr) of silica powders were added into composites. From characterizing the composite with PMNT powders, a porosity decreased with increasing silica added content resulting in an increasing trend of tensile strength while a percent elongation decreased. Dielectric constant (&) increased as silica concentration increased up to 15 phr. However, & was suppressed when the silica content was 20-25 phr. The & increased again when the content reached 30 phr. Dielectric loss (tand) was not depended on silica content. Ferroelectric properties of composites were degraded when silica concentration increased. Output voltage generated reached a maximum value of 28 V/J which was found in the composite with 15 phr silica. The prepared PMNT ceramic had the true density of 7.51 g/cm3 and the grain size ranging from 4 to 5 μm. It possessed & and tan values measured at 200 kHz and at room temperature of 2134 and 0.033, respectively. The values of remnant polarization, coercive field, piezoelectric coefficient, and piezoelectric voltage coefficient of 26.38 μC/cm2, 7.54 kV/cm, 383 PC/N and 20.41x103 V⚫m/N, respectively. From characterizing composites in which bulk PMNT ceramics were embedded between NR/100PMNT composite sheets, the generated output voltage reached the maximum value of 35 V/J which was found in the composite with the sheets containing 20 phr silica. The all obtained result indicates that the NR/100PMNT composite with 15 phr silica is suitable for using as flexible sensors while the bulk ceramics embedded- composite with 20 phr silica is applicable for improving to apply in energy harvesting floors which partially helps to add value to natural rubber.