Electrical and thermal properties of twin-screw extruded multiwalled carbon nanotube/epoxy composites

Karippal, Jeena Jose and Narasimha Murthy, H. N. and Rai, K. S. and Krishna, M. and Sreejith, M. (2010) Electrical and thermal properties of twin-screw extruded multiwalled carbon nanotube/epoxy composites. Journal of Materials Engineering and Performance, 19 (8). pp. 1143-1149. ISSN 1059-9495

Text (Full Text) Electrical and Thermal Properties.pdf - Published Version Restricted to Registered users only Download (604kB) | Request a copy

Abstract

This paper presents the experimental results of dispersing multiwalled carbon nanotubes (MWNTs) into epoxy (space grade structural adhesive) nanocomposites using co-rotating twin screw extrusion process. Two sets of specimens were prepared; set 1 with ultrasonication for predispersing MWNT before extrusion and set 2 direct dispersion of MWNT in the extruder. MWNT was loaded up to 8 vol.% in both the sets. The specimens were characterized for room temperature volume and surface resistivities as per ASTM D257 using Keithley Model 6517 and for thermal conductivity in the temperature range −50 to 150 °C as per ASTM E 1530 using Thermal Conductivity Instrument (TCI) 2022 SX211. The volume resistivity of sets 1 and 2 decreased to an extent of 1011 and 109 respectively. The surface resistivity drop was of the order of 109 for both the sets. These drops corresponded to the maximum MWNT loading of 8 vol.%. Electrical conductivity values of the specimens were fitted into the Power Law Model to evaluate the critical exponent. Both sets 1 and 2 showed increase in thermal conductivity with increase in temperature in the testing range. Thermal conductivity increased with increase in filler loading and the maximum increase was 60% at 150 °C in case of 8 vol.% MWNT nanocomposites for set 1. The corresponding value for the set 2 was 25%. Thermal conductivity values were predicted using Lewis Nielson model. DSC of the specimens showed increase in glass transition temperature with increase in filler loading. The dispersion of the nanofillers was studied using SEM and the surface morphology using AFM.

Item Type:	Article
Subjects:	M Polymer Science > Polymer Science
Divisions:	PG Centre Mandya > Polymer Science
Depositing User:	LA manjunath user
Date Deposited:	05 Jul 2019 10:20
Last Modified:	05 Jul 2019 10:20
URI:	http://eprints.uni-mysore.ac.in/id/eprint/4775

Actions (login required)

View Item