Nanoscale fillers. Fillers for high oxygen permeability polymer films

Abstract

A wide range of polymer film products are available with varying degrees of permeability to a variety of gases, from oxygen to water to aromatic species. The barrier properties are determined primarily by the choice of the matrix polymer, and fine tailoring can be introduced through the addition of filler materials such as inorganic platelets and polymer blend materials. It was identified that hollow and porous addition of such particles appears little studied. Gel particles were prepared by free radical emulsion polymerisation of styrene and DVB in presence of hydrophobic solvents. Porous particles were prepared by the surfactant free emulsion copolymerisation of VBC and DVB, followed by Friedel- Crafts alkylation to yield hypercrosslinked microporous nanoparticles. Porous and gel particles were added to polymer films and the oxygen permeability and mechanical properties of these films determined. It was found that the addition of hypercrosslinked microporous nanoparticles increased the oxygen permeability of the films up to 〜50 % when added at 40 wt% loading. Further to these studies, hollow nanoparticles were prepared by the emulsion phase ATRP of DVB when initiated by mPEG-6-PS inisurf in the presence of a hydrophobic solvent.