This study aims to improve low intrinsic ductility of poly (lactic acid) (PLA) by using a novel bio-sourced plasticizer environmentally friendly and cost-effective and to get a fully biodegradable material with potential application in films manufacturing. For that purpose, commercial sunflower oil (SO) was epoxidized and epoxidized sunflower oil (ESO) was used as plasticizer for PLA. To investigate ESO potential as plasticizer for PLA, its plasticizing effect was compared with commercial epoxidized soya bean oil (ESBO). Bioblends based on PLA and epoxidized vegetable oils (EVO) as bioplasticizers were prepared. The plasticizers (ESO or ESBO) were respectively compounded with PLA at 10, 20, 30, and 40 wt%. Mechanical (tensile and Shore D hardness), thermal (differential scanning calorimetry (DSC), thermogravimetric analysis (TGA)) and morphological properties (optical microscopy and scanning electron microscopy (SEM)) were characterized. The results showed that the addition of ESO or ESBO to PLA decreased tensile strength and tensile modulus compared to neat PLA but increased elongation at break for which an optimum (9 %, 16 and 34 % for ESBO, ESO_5.5 % and ESO_6.5 % respectively) was reached at a content of 20 wt% of plasticizer. The structures of the obtained plasticized PLA were confirmed by FTIR spectroscopy. The thermal properties (DSC), such as glass transition temperature (T_g) and melting temperature (T_m) were slightly decreased by addition of plasticizer into PLA, indicating that plasticizer increases the chain mobility and SEM analysis proved successful modification on the PLA brittle morphology with addition of EVO. On the other hand, TGA results revealed increase in the thermal stability. Also the results showed the effect of the EVO weight and the epoxy content (O.O value) on the improvement of the properties of PLA. ESO_6.5 % at 20wt% was an efficient plasticizer for PLA.

本研究旨在通过使用一种新型的生物来源增塑剂来改善聚乳酸 (PLA) 的低固有延展性，该增塑剂对环境友好且具有成本效益，并获得一种在薄膜制造中具有潜在应用的完全可生物降解材料。为此，商业向日葵油 (SO) 被环氧化，环氧化葵花籽油 (ESO) 被用作 PLA 的增塑剂。为了研究 ESO 作为 PLA 增塑剂的潜力，将其增塑效果与商业环氧化大豆油 (ESBO) 进行了比较。制备了基于 PLA 和环氧化植物油 (EVO) 作为生物增塑剂的生物混合物。增塑剂（ESO 或 ESBO）分别以 10、20、30 和 40% 的重量与 PLA 混合。机械（拉伸和肖氏 D 硬度）、热（差示扫描量热法 (DSC)、热重分析（TGA））和形态特性（光学显微镜和扫描电子显微镜（SEM））进行了表征。结果表明，与纯 PLA 相比，向 PLA 中添加 ESO 或 ESBO 降低了拉伸强度和拉伸模量，但增加了断裂伸长率，最佳（ESBO、ESO 分别为 9%、16% 和 34%）在增塑剂含量为 20 重量％时，分别达到_{5.5 %}和 ESO _{6.5 %} )。所得增塑PLA的结构通过FTIR光谱证实。通过在 PLA 中添加增塑剂，热性能 (DSC)，如玻璃化转变温度 (T _g ) 和熔融温度 (T _m ) 略有下降，表明增塑剂增加了链的流动性，SEM 分析证明对 PLA 脆性的成功改性添加 EVO 后的形态。另一方面，TGA 结果显示热稳定性增加。结果还显示了 EVO 重量和环氧含量（OO 值）对 PLA 性能改善的影响。欧洲南方天文台_6.5% 20wt% 是 PLA 的有效增塑剂。