Effects of fullerene derivatives on the gas permeability of thermoplastic polyurethane elastomers

Abstract

In an effort to improve the gas barrier properties of thermoplastic polyurethane (TPU) elastomers, fullerene derivatives were added as fillers, and the resulting O 2 and CO 2 permeabilities were analyzed. The addition of 5 wt % polyhydroxylated fullerene {fullerenol [C 60 (OH) n ] mixture, where n 5 6-12} decreased the gas permeability by approximately 10-20%. According to the hole volumes computed with the results from positron annihilation lifetime spectroscopy, the addition of fullerene derivatives did not produce any changes in the hole volumes of the TPUs. Thus, the reduction in the TPU gas permeability was not caused by changes in the hole volumes. Instead, an inhibited diffusion of gas molecules by fullerene particles was deduced as the cause of the decrease in gas permeability from changes in the diffusion coefficient with temperature. The addition of urethanized fullerene, prepared through the chemical modification of fullerenol, markedly affected the TPU gas barrier properties. As compared to fullerenol addition, the gas barrier properties improved approximately fourfold for O 2 and approximately fivefold for CO 2 . These results suggest that the dispersability of urethanized fullerene in TPU was higher than that of fullerenol. We found that the gas barrier properties were independent of the structure of polyol.

Transport performance in novel elastomer nanocomposites: Mechanism, design and control

“…approximately fivefold for CO 2 compared with the counterpart with fullerenol. This difference was due to the higher dispersibility of urethanized fullerene in TPU [276]. As a typical one-dimensional filler, CNTs are also capable of lowering the permeability of various rubbers.…”

“…Many elastomers have been utilized to attempt to form nanocomposites with high barrier properties, including NR [272,[289][290][291], SBR [292], NBR [281,293], HNBR [278], butadiene rubber (BR) [294], EPDM [281], isobutene-isoprene rubber (IIR) [279,285,295], CR [296], chlorinated isobutene-isoprene rubber [280], FKM [297], and PU [276,298].…”

Mechanical, flow and electrical properties of thermoplastic polyurethane/fullerene composites: Effect of surface modification of fullerene

“…Majority of TPU application is across a range of markets including automotive, sporting goods, medical devices, tubes, hoses, wires and cables. In addition to these general applications, polyurethane can gain shape memory actuation when they are loaded with conductive carbonaceous fillers [19][20][21], they can be used in electronic packaging thanks to their high flexibility [22], because of their electro-striction effect, they can be used as an actuator [23,24] and it can gain gas barrier property [25] with the addition of fullerene particles.…”

Free-volume correlation with mechanical and dielectric properties of natural rubber/multi walled carbon nanotubes composites

“…A dependence between the structure and properties of elastomers has also been systematically drawn using PALS. For instance, PALS is correlated with the mechanical and dynamic mechanical properties of nanocellulose filled polyurethane [15] whereas it is used to derive the gas permeability of the same polymer using fullerene as the reinforcement [16]. Our group has also addressed the various properties of polymer nanocomposites using the PALS technique [17,18], wherein the method was simply applied to characterize the clay and spherical particles filled composites.…”