Propriedades mecânicas e de barreira de nanocompósitos poliméricos na forma de filmes.

Abstract

This work deals with mechanical and barrier properties of polyolefin films. Sodium bentonite (1%) was added to three polyolefin matrices (PP, HDPE and LDPE) and films prepared by single screw extrusion with a flat die. The extruder was operated under appropriate conditions for each of the matrices. The influence of bentonite addition on the tensile and water vapour permeability of these films was investigated. Tests were conducted under controlled humidity and temperature. Tensile properties of polymer films were hardly affected (elongation at break) or reduced (tensile strength) by bentonite incorporation, which was attributed to poor polymer/filler interfacial adhesion. Water vapor permeability of the films investigated increased in the order PP < HDPE < LDPE. Bentonite addition led to increased film permeability.