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The effect of the noncovalent functionalization of CNT by ionic liquid on electrical conductivity and electromagnetic interference shielding effectiveness of semi‐biodegradable polypropylene/poly(lactic acid) composites
Author(s) -
Soares Bluma G.,
Cordeiro Elisangela,
Maia Jorge,
Pereira Elaine C. L.,
Silva Adriana A.
Publication year - 2020
Publication title -
polymer composites
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.577
H-Index - 82
eISSN - 1548-0569
pISSN - 0272-8397
DOI - 10.1002/pc.25347
Subject(s) - materials science , carbon nanotube , composite material , surface modification , crystallization , polypropylene , electromagnetic shielding , nanocomposite , dispersion (optics) , ionic liquid , phase (matter) , scanning electron microscope , chemical engineering , chemistry , organic chemistry , engineering , catalysis , biochemistry , physics , optics
Semi‐biodegradable polypropylene/poly(lactic acid) (PLA) (70:30 wt.%) blend with co‐continuous structure was used for the development of conducting composites. Multi‐walled carbon nanotube (CNT) and the noncovalently functionalized CNT with alkylphosphonium‐based ionic liquid (IL‐CNT) were used as conducting fillers. Relative high AC electrical conductivity was achieved by using 1 wt.% of CNT (around 10 −3 S/m). This property increased four orders of magnitude when IL‐CNT was employed. The effect of the functionalization with IL on the rheological, morphological and thermal properties was investigated. The DSC analysis also suggested that the filler (CNT or IL‐CNT) exerted strong influence on the cold crystallization of the PLA phase and also on the melt crystallization of the PP phase. The effect of the IL on the dispersion of CNT was also confirmed by rheological measurements and transmission electron microscopy. An increase of the attenuation of the electromagnetic radiation, that is, an improvement of the electromagnetic interference shielding effectiveness (EMI SE) in the X‐band microwave region (8‐12 GHz) was achieved by using IL‐CNT, with an important influence of the absorption mechanism to this property.