New nanocomposite design from zeolite and poly(lactic acid)

We studied the effect of zeolites (NaAlO2, SiO2) and their dispersion in biopolymer poly(lactic acid) (PLA), with a particular interest in the improvement of antibacterial properties, permeability to water vapor, oxygen permeability and mechanical properties. Using two zeolite particles of a different size: micrometric (zeolites) and nanometric (Nanozeolites) sizes, we prepared these composites using the melt mixing process/technique by means of a Brabender mixer. We started by characterizing the morphology of these composite materials using a scanning electronic microscope (SEM) and NanoSIMS microscopies. A good dispersion of nanozeolites is ensured only when a stabilizer (polyethylene glycol (PEG) with M=1000 g/mol) is used. Then a comparative study on the physical (gas barrier properties) and mechanical properties (high strain mechanical properties) of these two families of composites has been conducted. It was shown that these two families present almost similar barrier and anti-bacterial properties. The strong point of the nanocomposites is their good mechanical properties (high young modulus and high tensile strength). These mechanical and physical properties of the nanocomposites are ensured only when a PEG of M=1000 g/mol is used as stabilizer. (C) 2015 Elsevier B.V. All rights reserved.