Elaboration of porosity for the alumina particle surfaces/ bimodal PP composite cast films under continuous stretching

Abstract

AbstractEfforts have been focused on developing an interrelationship between machine direction orientation (MDO)/material variables and the porosity of Al2O3 particulate‐filled orientable PP for various applications. Composite films were prepared by cast‐extrusion followed by stretching up to 100% and 200% by the MDO machine. Cavitation could occur during film stretching when the adhesion between dispersed alumina and continuous polypropylene phase failed. Composite films with modified micro‐particles and also nano ones could not generate any voids. On the other hand, composite specimens of unmodified micro‐alumina particles generated micro‐pores in the joint between dispersed particles and polymer during the hot stretching. Beta nucleation in these films, plays an important role in the generated ductility of the specimens. Cavitation effectiveness (no. of voids) or film permeability depended on the size and amount of alumina particles, in addition to the ratio and temperature of stretching. Cavitation particles with a size range of 0.7–3 μm, create cavities of about 3–7 μm. Generation of voids, by drawing environmentally friendly and antimicrobial active alumina particles, can be utilized in the fabrication of sustainable hygiene polypropylene films with desirable separation abilities for gases or small molecules. Furthermore, the polypropylene/alumina composite films have the potential for microwaveable packaging.