Analysis of the Suitability of Poly(lactic acid) in Rotational Molding Process

This paper is aimed to study the suitability of poly(lactic acid) (PLA) for the production of biodegradable containers by rotational molding. To increase polymer toughness, PLA was plasticized with poly(ethylene glycole) (PEG), with an average molecular weight of 400 g/mol. Differential scanning calorimetry performed on neat PLA and PEG‐plasticized PLA showed that the former is characterized by a better quenchability than the latter. Neat PLA and PEG‐plasticized PLA were used for the production of rotational molding prototypes of simple shape. Owing to its very slow crystallization kinetics, a completely amorphous PLA was obtained by rotational molding with air cooling. As a consequence, rotomolded PLA is characterized by a good ductility and toughness. In contrast, the higher crystallization rate induced by the addition of PEG did not allow to obtain an amorphous structure for plasticized PLA, even if faster cooling was attained by water spraying. As a consequence, the PEG‐plasticized PLA, characterized by a semicrystalline structure, shows a lower ductility and toughness compared to neat PLA.