Transport and mechanical properties of blends of poly(ϵ‐caprolactone) and a modified montmorillonite‐ poly(ϵ‐caprolactone) nanocomposite

Abstract

The structural characterization and transport properties of blends of a commercial high molecular weight poly(ϵ‐caprolactone) with different amounts of a montmorillonite‐poly(ϵ‐caprolactone) nanocomposite containing 30 wt % clay were studied. Two different vapors were used for the sorption and diffusion analysis—water as a hydrophilic permeant and dichloromethane as anorganic permeant—in the range of vapor activity between 0.2 and 0.8. The blends showed improved mechanical properties in terms of flexibility and drawability as compared with the starting nanocomposites. The permeability (P), calculated as the product of the sorption (S) and the zero‐concentration diffusion coefficient (D0), showed a strong dependence on the clay content in the blends. It greatly decreased on increasing the montmorillonite content for both vapors. This behavior was largely dominated by the diffusion parameters. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1118–1124, 2002

Investigation of water absorption in clay-reinforced polypropylene nanocomposites

“…The retarded relaxation, in turn, reduces the diffusion of small molecules through the nanocomposites. Similar results have been obtained by Gorrasi et al [14] and Yano et al [15]. These authors concluded that while the permeability decreased significantly, the amount of moisture absorbed remained mostly unchanged.…”

“…This was attributed to the fact that the oriented clay platelets block the advancement of the solvent molecules and force them to follow a more tortuous path. This tortuous path mechanism was further supported by modelling work [13] and other experimental results where clay fillers with larger aspect ratio showed a larger improvement in the barrier properties [14]. Bharadwaj [13] has proposed another explanation for such a process.…”

Preparation and characterization of maleated thermoplastic starch‐based nanocomposites

“…By adding the nanoclay at a loading level as tiny as 1 wt %, the water vapor permeability was reduced to 810 g/m 2 day for the Cloisite 30B-filled PBAT-g-MTPS nanocomposites, and more significantly to 575 g/m 2 day for Cloisite Nafilled PBAT-g-MTPS blown film. The lowering of the WVTR could be explained by the intercalation/partial exfoliation of the clay nanoplatelets, 8,37 which would create a more tortuous path for the diffusion of water vapor through the PBAT-g-MTPS film. Clearly, a more significant reduction in water vapor permeability was detected for Cloisite Na-filled films.…”

Bionanocomposites Assembled by “From Bottom to Top” Method

“…Among potential nanofillers, MMT nanoclays are widely used in producing of bionanocomposites due to their availability and deeply studied intercalation chemistry (see Chapter 5) [250]. A vast variety of modern hybrid and biohybrid materials based on clays, including those that contain living entities or their fragments, are produced.…”