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Phase‐selective micro‐structural effects on rheological‐networks, segmental relaxation, and electrical conductivity behavior of melt‐mixed polyamide‐12/polypropylene‐multi walled carbon nanotubes ternary nanocomposites
Author(s) -
Sethy Sucharita,
Samantara Laxmi,
Satapathy Bhabani K.
Publication year - 2020
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.25381
Subject(s) - materials science , nanocomposite , carbon nanotube , polyamide , composite material , polypropylene , rheology , dynamic mechanical analysis , volume fraction , percolation threshold , ternary operation , electrical resistivity and conductivity , polymer , engineering , computer science , electrical engineering , programming language
Morphological interpretations and their correlation with biphasic rheological networks and subsequent segmental relaxation, and electrical conductivity were comprehensively addressed for polyamide‐12/polypropylene‐multi‐walled carbon nanotubes (PA‐12/PP/MWNT) based ternary nanocomposites fabricated by melt mixing route. The partial migration of MWNT from PP to PA‐12 phase is evident from the spreading coefficient estimations based on interfacial dynamics and transmission electron microscopy (TEM) analysis. Melt rheology measurements based on scaling parameters associated with various viscosity models such as, Cross model, Carreau‐Yasuda model, and Berzin model indicated systematic variation in network rigidity that is in tune with dispersion‐selective nano‐morphology of the nanocomposites. The phase inversion was attained for composition in the range of 50 to 60 wt% of PP‐MWNT content as indicated by Han plot and van‐Gurp Palmen plots which is in direct correspondence to dispersed‐phase‐volume‐fraction range of ~0.3‐0.36. Broadening of loss‐peaks vis‐a‐vis enhanced storage moduli in dynamic mechanical analysis (DMA) signifies the reduced mobility (of polyamide chains) and hence the enhanced stiffness. The electrical conductivity of the nanocomposites post‐annealing decreased at temperatures above 100°C demonstrating the temperature‐sensitive morphology disruption (of the conductive PP‐MWNT channels) in the nanocomposites.