dc.description.abstract |
Electromagnetic (EM) wave is a form of energy that is emitted and absorbed by charged
particles. EM pollution becomes the fourth pollution next to air, water and sound
pollution. Current technologies and all electronic devices are the source of this
pollution, which can cause cancer, thermal, hereditary problems. These pollutions are
common in electric vehicles in which extremely low frequencies (1 – 300 Hz), radio
frequencies (100KHz – 300 GHz) are generated from sensors, electronic security
systems, charging system, car network, GPS, Bluetooth, Wi- Fi and other control
systems in side electric vehicles that cause health problems at long time exposure for
passenger and drivers. To take part in solving this problem pine wood biochar
(PWB)/high density polyethylene (HDPE) composites with good electromagnetic
shielding effectiveness were successfully fabricated using melt blending and hot
compression molding for electric vehicle battery and high power traction component
shielding. High temperature (620
o
C) pyrolyzed PWB fabricated with large pore sizes,
pore volumes, high specific surface areas and higher carbon contents compared to other
biochars (coffee husk, sugar cane bagasse and maize cob) that enables it to have good
electrical conductivity, thermal stability, and electromagnetic shielding properties when
combined with HDPE plastic. Different weight percentages (10, 20, 30 and 40 wt. %)
of PWB had been melt blended and molded with HDPE, and characterized
experimentally. The results showed that PWB enhance the electrical conductivity,
thermal stability and EMI shielding effectiveness (SE) of HDPE significantly. In
particular, the PWB/HDPE composite with 30 wt. % PWB exhibited the highest
thermal conductivity of 2.219 W/mK, and 40 wt. % PWB composites achieved the
highest electrical conductivity of 4.67 x 10
-7
S/cm and EMI SE of 44.03 dB (99.99%
attenuation) at 2.1 GHz. These good results show a new, environmentally available,
cost effective, scalable ways to use waste biomasses and recycled high density
polyethylene plastic wastes in polymer composites for EMI shielding applications.
Keywords: Biochar, HDPE, Composites, Thermal stability, Electrical conductivity,
Shielding effect, Electromagnetic |
en_US |