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Composites of Single‐Walled Carbon Nanotubes and Styrene‐Isoprene Copolymer Latices
Author(s) -
Ha Mai L. P.,
Grady Brian P.,
Lolli Giulio,
Resasco Daniel E.,
Ford Warren T.
Publication year - 2007
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200600521
Subject(s) - copolymer , materials science , miniemulsion , carbon nanotube , styrene , polymerization , composite material , polymer , isoprene , monomer , emulsion polymerization , polymer chemistry , composite number
Composites of a styrene‐isoprene copolymer and SWNTs were prepared by emulsion and miniemulsion polymerization in the presence of SWNTs, as well as by mixing dispersed SWNTs with a styrene‐isoprene copolymer latex after polymerization. For the former, the surfactant was displaced from SWNTs to monomer droplets leading to SWNT aggregation. Mixing dispersed SWNTs with latex after reaction was able to preserve SWNT dispersion and gave a polymer composite with an electrical percolation threshold of 0.2%. Dynamic mechanical measurements of film samples in tension showed that the composites had a measurable modulus above T g , indicating entanglement formation. The modulus above T g was strongly temperature dependent, confirming shear measurements that have shown entanglements in SWNT/polymer composites both polymer and nanotubes.