Moisture effects on water vapor permeability of polylactide films

The moisture barrier properties of polylactide films were investigated by studying both the moisture sorption and the water vapor transmission of a commercial film. The first part of this research focused on the moisture sorption of the PLA film showing that it was not linear with the relative humidity, in the range between 11 and 86%. In the second part of this work, the influence of relative humidity on the water vapor transmission rate (WVTR) was investigated at 38\ub0C by two different methods. According to the results, the WVTR values varied linearly with relative humidity differences on the two sides of the film, from 10 to 90%. Therefore, it was concluded that the absorbed moisture did not affect the water vapor permeability