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Evaluation of the rheological and electrical percolation of high‐density polyethylene/carbon black composites using mathematical models
Author(s) -
SiIva Moacy P.,
Cavalcanti Shirley N.,
Alves Amanda M.,
Freitas Daniel M. G.,
Agrawal Pankaj,
Vilar Eudesio O.,
Mélo Tomás. J. A.
Publication year - 2021
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.25738
Subject(s) - materials science , percolation threshold , carbon black , composite material , rheology , percolation (cognitive psychology) , electrical resistivity and conductivity , polyethylene , volume fraction , electrical conductor , percolation theory , conductivity , natural rubber , chemistry , neuroscience , electrical engineering , biology , engineering
In this work, conductive polymer composites (CPCs) of bio‐based polyethylene (BioPe) containing different concentrations of carbon black (CB) were developed. By using oscillatory rheology analysis, a Newtonian plateau was observed in BioPe, and all BioPe/CB composites had a behavior of a pseudo‐solid and that composites with volume fractions ranging from 0.24 to 0.56 presented higher viscosity, storage, and loss modulus. This suggests the formation of a percolated network and by using the power‐law models, it was observed that the electrical percolation threshold was higher than the rheological percolation threshold. The electrical conductivity was measured using the four‐point probe method and a sigmoid model was used to predict the CPCs' electrical conductivity percolation threshold. The results indicated that the four‐point probe method presented satisfactory results according to the calculated standard deviations and voltage–current characteristics for each round of measurements considering the same ranging as used in rheology analysis. The analytical model used showed a coefficient of determination ( R 2 ) higher than 95%, allowing the prediction of the electrical conductivity of the CPC and the percolation threshold as a function of the volumetric fraction of the CB.