Journal of Membrane Science, 2017, vol 540pp. 212-218
DOI:10.1016/j.memsci.2017.06.051
Abstract
Modification of synthetic, high aspect ratio clay with 6-aminocaprohydroxamic acid hydrochloride pushes the interaction between the polyvinyl alcohol (PVA) matrix and the filler to the level where the waterborne nanocomposite becomes rather insensitive to swelling, even at an elevated relative humidity (RH). The modifier can form strong hydrogen bonds with the hydroxyl groups of PVA via the hydroxamic acid functional group. This prevents the swelling of crystalline PVA domains. Perfectly textured nanocomposite films are obtained by spraying polymer-filler suspensions. The combination of the various effects shifts the onset of significant swelling of the nanocomposites to high RH regions. Even at 90% RH, surprisingly low oxygen and water vapor transmission rates (0.11cm3mā2 dayā1 barā1 and 0.18gmā2 dayā1, respectively, for a coating of 0.42Āµm) are observed that may render PVA-based, waterborne coatings interesting for food packaging applications.
