Mass transport and high barrier properties of foodpackaging polymers

摘要: Several novel computer simulation models were developed for predicting electrical, mechanical, thermal and diffusion properties of materials with complex microstructures, such as composites, semi-crystalline polymers foams. A Monte Carlo model simulating solvent through spherulitic semicrystalline polyethylene was developed. The spherulite model, based on findings by electron microscopy, could mimic polyethylenes crystallinities up to 64 wt%. Due the dendritic structure spherulites, surprisingly independent aspect ratio individual crystals. correlation found between geometrical impedance factor (τ) average free path length penetrant molecules in amorphous phase. new relationship volume crystallinity τ. equation confirmed experimental diffusivity data Ar, CH4, N2 n-hexane polyethylene. For electrostatics, a analytical mixing formulated predict effective dielectric permittivity 2- 3-component composites. Results obtained showed clearly better agreement corresponding finite element than previous models. accordance nanocomposites mica/polyimide epoxy/ hollow glass sphere Two composite electrostatics It is generally recognized that fracture toughness slow crack growth depend concentrations tie chains trapped entanglements bridging adjacent crystal layers polymer. method calculating these simulations revealed concentration substantial probably has major impact stress transfer rubber modulus data. (FEM) including heat determining gases/solutes polymers. As part FEM two accurate pressure-volume-temperature (PVT) relations To solubility, current "state art" NELF improved PVT chemical interactions using Hansen solubility parameters. diffusivity, free-volume derived group contribution methods. All used without adjustable parameters gave results data, recent polycarbonate poly(ether-etherketone) pressurized nitrogen at 67 MPa.