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Electrical, rheological, and mechanical properties copolymer/carbon black composites
Author(s) -
Alves Amanda M.,
Cavalcanti Shirley N.,
Silva Moacy P.,
Freitas Daniel M. G.,
Agrawal Pankaj,
Mélo Tomás J. A.
Publication year - 2021
Publication title -
journal of vinyl and additive technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.295
H-Index - 35
eISSN - 1548-0585
pISSN - 1083-5601
DOI - 10.1002/vnl.21818
Subject(s) - materials science , carbon black , composite material , copolymer , percolation threshold , polyethylene , volume fraction , crystallinity , composite number , polymer , electrical resistivity and conductivity , natural rubber , engineering , electrical engineering
This work aims to evaluate the electrical conductivity and the rheological and mechanical properties of copolymer/carbon black (CB) conductive polymer composites (CPCs). The copolymers, containing ethylene groups in their structure, used as matrix were polyethylene grafted with maleic anhydride (PE g MA), ethylene‐methyl acrylate–glycidyl methacrylate (EMA‐GMA), and ethylene‐vinyl acetate (EVA). For comparison purposes, bio‐based polyethylene (BioPE)/CB composites were also studied. The electrical conductivity results showed that the electrical percolation threshold of BioPE/CB composite was 0.36 volume fraction of CB, whereas the rheological percolation threshold was 0.25 volume fraction of CB. The most conductive CPC was BioPE/CB. Among the copolymer/CB CPCs, PE g MA/CB showed the highest conductivity, which can be attributed to the fact that the PE g MA copolymer had higher crystallinity. It also has a higher amount of ethylene groups in its structure. Torque rheometry analysis indicated that EMA‐GMA copolymer may have reacted with CB. Rheological measurements under oscillatory shear flow indicated the formation of a percolated network in BioPE/CB and copolymer/CB composites. Morphology analysis by scanning electron microscopy (SEM) indicated the formation of a percolated network structure in BioPE/CB composite and finely dispersed CB particles within the PE g MA copolymer. Wetting of CB particles/agglomerates by the copolymer matrix was observed in EVA/CB and EMA‐GMA/CB composites. Conductive CB acted as reinforcing filler as it increased the elastic modulus and tensile strength of BioPE and the copolymers.