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Kuala Lumpur, Malaysia

Yong K.C.,Rubber Research Institute of Malaysia
Rubber Chemistry and Technology | Year: 2011

Colorable, sulfur-vulcanized epoxidized natural rubber-polyaniline dodecylbenzenesulfonate (ENR-PAni.DBSA) blends with good electrical conductivities (up to 10 -1 S · cm -1) and good mechanical properties (including high damping) were successfully prepared. An effect of conductive filler particle's surface area and shape was studied for the vulcanized blends by testing them through 900 cycles of straining. The elongated shape of PAni.DBSA particles (as observed by using transmission electron microscope) did contribute to the very low percolation threshold for unstrained samples (about 3.0 wt. % of PAni.DBSA loading) and the reproducible electrical behavior (≥95% retention of original unstrained value) for samples under straining cycles. With the ideal mechanical properties and reproducible electrical behavior, these vulcanized blends do have good potential to be used as flexible smart materials that can correspond to the straining process.

Thermoplastic vulcanisates [TPVs] based on natural rubber, polypropylene and dodecylbenzenesulfonic acid-doped polyaniline [PAni.DBSA] with useful electrical conductivities (up to about 1.2 S cm-1) were produced by using an internal mixer. A very low electrical percolation threshold (about 2.0 wt.%/1.13 volume % of PAni.DBSA) was achieved for TPVs prepared via this method. All the TPVs exhibited useful physical properties and also a reasonable good electromagnetic interference shielding effectiveness [EMI SE]. The TPVs could be recycled up to 4 times without significant loss of their EMI SE, electrical and physical properties. © Smithers Information Ltd., 2016.

Blends of poly(butadiene-co-acrylonitrile) [NBR] and poly aniline dodecylbenzenesulphonate [PAni.DBSA] with electrical conductivities up to 10 -1 S.cm -1, have been successfully prepared using the technique of solution mixing and casting. Compatibility of both NBR and PAni.DBSA was found to be maximised by the introduction of hydroquinone as a compatibiliser. Blends prepared with added hydroquinone exhibited the lowest electrical conductivity percolation threshold and were more conductive than the ones without any compatibiliser. Transmission electron micrographs of blends with added compatibiliser showed the lowest level of phase separation. FT-IR spectra and DSC thermal of blends with added compatibiliser also showed the largest peak and temperature shifts, respectively. These phenomenons occured due to the higher intermolecular interactions between the two blended polymers in the presence of hydroquinone.

Yong K.C.,Rubber Research Institute of Malaysia
Journal of Applied Polymer Science | Year: 2012

Dicumyl peroxide (DCP) vulcanized poly(butadiene-co-acrylonitrile)- polyaniline dodecylbenzenesulfonate [NBR-PAni.DBSA] blends were successfully prepared by using the practical thermomechanical mixing method. The effect of alignment of PAni.DBSA particles on the mechanical and electrical properties of vulcanized blends was studied (by passing the blends through a two roll-mills). All vulcanized blends strained parallel to the flow direction when passed through the two roll-mills had their electrical conductivities enhanced with increasing strain in tension. Good historical memory in term of the electrical conductivities during three cycles of straining (with 300 times of strain loading and unloading motion for each cycle) was observed for all vulcanized blends (99% retention of original value before straining). These vulcanized blends also showed better mechanical properties (i.e., higher tensile strength and tear strength) than the ones strained perpendicularly to the flow direction. With the ideal mechanical properties and reversible electrical behavior, this type of blend can potentially emerge as a new class of flexible smart material. © 2011 Wiley Periodicals, Inc.

Electron beam irradiation technique was successfully used for the first time in order to crosslink the natural rubber-polyaniline dodecylbenzenesulphonate [NR-PAni. DBSA] blends. Significant increases in crosslink densities of all blends with doses of irradiation up to 200 kGy were obtained and a reasonably high crosslink density level (in the order of 10 4 mol/cm3) was achieved. All electron beam-irradiated NR-PAni.DBSA blends showed good tensile properties with tensile strength up to about 19.7 MPa. This kind of irradiation induced-crosslink technique at doses up to 200 kGy also did not affect electrical properties after being sufficiently stabilised for at least 24 hours. The irradiated NR-PAni.DBSA blends also exhibited good electrical properties, i.e. a single conductivity percolation threshold and high conductivities up to the order of l0-2 S.cm -1. In other words, there is a good potential of using electron beam irradiation technique to prepare highly crosslinked, electrically conductive NR-PAni.DBSA blends.

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