Polyethylene Nanocomposite Heat-Sealants with a Versatile Peelable Character

A novel heat-sealing performance is achieved by polyethylene (PE) nanocomposites reinforced by ethylene vinyl acetate (EVA) and montmorillonite (MMT). Appropriate nanocomposite design leads to hermetic seals with a general peelable/easy-open character across the broadest possible sealing temperature range. Observations of the fracture seal surfaces by infrared spectroscopy and electron microscopy reveal that this behavior originates from a synergistic effect of the EVA copolymer and the montmorillonite clav nanofiller. Namely, the combination of EVA-copolymers and MMT nano-fillers provides sufficiently favorable interactions for nanocomposite formation and mechanical robustness, but weak enough interfacial adhesion to promote a general cohesive failure of the sealant at the EVA/MMT interfaces.