Synthesis and properties of electromagnetic wave shielding polymer materials with low flammability

Abstract

Novel polyethylene-and polypropylenebased electromagnetic wave shielding and absorbing composite materials with low combustibility, enhanced thermal and mechanical properties, containing graphite, grinded wood, and fire retardants, were developed and investigated. Flame-resistance, thermal and mechanical properties of these materials was investigated. Electromagnetic wave reflection coefficients over the frequency range 20-40 GHz were measured; at moderate concentration (10-15%) of functional filler, reflection coefficient can be as low as À16 dB for PE and À11 dB for PP composite, respectively. Coke formation mechanism was investigated, the principal role in this process is attributed to aromatization and condensation of aromatic compounds with the formation of polycyclic aromatic systems, an important role of phosphoric acids in accelerating this process was found.

Multifunctional polymer composites for intelligent structures

“…Details of experimental techniques are given elsewhere [21]. Oxygen index (OI) of the samples increases when fire retardants, PBMA and OG, are added.…”

The Effect of Graphite on the Water Uptake, Mechanical Properties, Morphology, and EMI Shielding Effectiveness of HDPE/Bamboo flour composites

“…Among these conductive fillers, graphite was deemed as having better commercial prospects due to its very low cost and high conductivity. Research indicated that PE and PP composites with 15% of graphite exhibited the optimal EMI SE of 16 dB and 11 dB in the range 20 to 40 GHz (Volkov et al 2010). But Panwar et al (2010) fabricated the PP/graphite composites using a melt mixing method, and the maximum value of EMI SE was measured to be as high as 44.12 dB at 2.76 GHz for the composites with 25% of graphite.…”