“…Therefore in this study an external additivation by plasticisers of different molecular weights was performed and the relative influence of these plasticisers on the structural (melting temperature, crystallinity), mechanical (Young's Modulus, tensile strength, elongation at break) and barrier (water vapour and oxygen permeability) properties of PHBV was analysed. For this purpose the plasticiser, commonly known in literature, propylene glycol (PG) [23,24], glycerol (G) [25,26], triethyl citrate (TEC) [27,28], castor oil (CO) [29], epoxidised soybean oil (ESO) [28,30] and polyethylene glycol (PEG) [31,32] were applied. PG, G, and TEC are low molecular weight substances in the range between 76 and 276 g mol À1 while CO, ESO and PEG are to be found in the range from 933 to 1000 g mol À1 .…”