Biodegradable Films made from low density polyethylene (LDPE), ethylene acrylic acid (EAA), polycaprolactone (PCL) and wheat starch for food packaging applications .3.

摘要

The mechanical properties and gas/water permeabilities of extrudates of low density polyethylene (LDPE), wheat starch and ethylene acrylic acid (EAA) or polycaprolactone (PCL) were studied after their conditioning at various relative humidities. Satisfactory agreement was found between the experimental values, pertaining the mechanical properties, and estimates obtained by applying several semiempirical equations. The presence of starch contents (>30%) or PCL had an adverse effect on the mechanical properties of LDPE/starch blends, whereas EAA acted as a compatibilizer by increasing the percentage elongation of the blends. Gas permeability and water vapour transmission rate increased proportionally to the starch/PCL content in the blend. Several theoretical and semiempirical calculations were also applied for gas permeability and possible interpretations were provided for the occasionally observed deviations between the experimental and the theoretical values.