Nanoclay/polypropylene composite for ethylene and carbon dioxide scavenging films

Abstract

Na-bentonite was treated with a surfactant (Stepantex™ SP-90) in order to prepare organobentonite; and 3-aminopropyltrimethoxysilane was also added to act as surface treatment. Because aluminum hydroxide and calcium hydroxide can enhance ethylene and carbon dioxide removal capacity, respectively, organobentonite and aluminum hydroxide/calcium hydroxide were incorporated into polypropylene with a compatibilizer (Surlyn® ionomer) in a twin screw extruder and fabricated into films by the blow film extrusion process. The organomodified-BTN was characterized by XRD and FTIR. The d-spacing of the organoclay increased when the surfactant was added and the C=O bond and –CH₂ of the surfactant occurred at 1740 and 2921 cm⁻¹, respectively. The degradation temperatures of those films were improved. The mechanical properties of the nanocomposite films were also investigated. When the present clay content of the organomodified-BTN was increased, it enhanced the Young’s modulus but decreased other tensile properties. Packaging films made of PP/organomodified-BTN can prolong the shelf-life of fresh fruit as the organomodified-BTN showed the potential for being an ethylene and carbon dioxide scavenger.