Characteristics of thermoplastic polyurethane composites containing surface treated multiwalled carbon nanotubes for the underwater applications

Abstract

Thermoplastic polyurethane elastomer (TPU) is used as an encapsulant in undersea sonar devices. In order to fabricate desirable composites for underwater applications, TPU prepared from poly(tetramethylene glycol) (PTMG), and methyl diphenyl diisocyanate (MDI) was blended with a multiwalled carbon nanotube (MWCNT). TPU grafted MWCNT (TPU-g-MWCNT) were prepared to fabricate a composite that has better mechanical strength and interfacial adhesion between the TPU matrix and the MWCNTs. The tensile strength of the composite increased with increasing MWCNT content. At a fixed MWCNT content in the composite, the TPU/TPU-g-MWCNT composite exhibited superior tensile strength compared to the TPU composite with pristine MWCNT. The swelling ratio of TPU composite with pristine MWCNT was higher than that of TPU. However, the swelling ratio of the TPU/TPU-g-MWCNT composite was lower than the latter when the composite contains more than 0.5 wt% of TPU-g-MWCNT. In addition, the TPU/TPU-g-MWCNT composite exhibited enhanced mechanical strength and a reduced swelling ratio as compared to TPU after being impregnated with seawater or paraffin oil. Open image in new window