For the DMA data, tan δ was plotted versus temperature for medium and high MW PLGA 50:50, and for low, medium, and high MW PLGA 75:25, shown in Figure . We did not examine the low MW PLGA 50:50 material, as the T g,β value of this material, found using the THz-TDS experiments, is below the temperature range which could be measured using the DMA technique, and thus could not be compared. Given that for all the materials studied the tan δ peaks at low temperatures are relatively broad, we specify the temperature range over which each tan δ peak spans and the maximum value obtained for each tan δ, β peak, listed in Table .