The impact of varying the copolymer composition of styrene–co‐butyl acrylate copolymers on the dispersion of montmorillonite (MMT) clay and the effect thereof on the transparency and water vapor barrier properties of the resultant films is assessed. The hybrid latexes containing MMT clay concentrations of 10–30 wt% are prepared using miniemulsion polymerization. The morphology of the resultant latexes shows that the MMT particles are predominantly adhered onto the surface of the latex particles. However, the transparency of the films suggests a fair dispersion of the MMT platelets in the matrix. The thickness‐normalized light transmittance for copolymers with 40 and 50 mol% styrene only decreases from 70% in the neat films to 50% in the nanocomposite films containing 30 wt% clay. The best optical properties are observed for the copolymers with 30 mol% styrene, in which the light transmittance only decreases from 85% (unfilled film) to 60% in the nanocomposite films containing 30 wt% clay. Overall, the water vapor barrier properties are much higher in the copolymer films with 30 mol% styrene due to the unique morphological organization of MMT platelets in the matrix.
This paper reports the development of a permeation test method to evaluate the transmission rate of a volatile organic compound, acting as a mineral oil simulant, through paper and plastic packaging materials. The method uses accelerated conditions, whereby the environment on the one side of a substrate is saturated with the vapor of a model organic compound, similar to mineral oil vapor, namely n-heptane. A suitable adsorbent is placed on the other side of the substrate to ensure a constant gradient of vapor pressure by adsorbing the organic vapor as it migrates through the substrate. This mechanism enables the measurement of the heptane vapor transmission rate through food packaging materials, which is an indirect measure of the mineral oil barrier properties. This research demonstrated that barrier-coated paperboards have the ability to behave in the same way as, and often even better than, commercial plastic films toward the migration of mineral oil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.