Ji Xiaoying, Guo Jia, Zeng Bingbing, Li Xiaopeng, Liao Xue, Fang Wanjiao, Liu Juan, Zheng Yu, Li Dongliang, Lei Jinshan
Cigar Fermentation Technology Key Laboratory of China Tobacco, China Tobacco Sichuan Industrial Co., Ltd., Chengdu 610101, China.
State Key Laboratory of Polymer Materials Engineering of China, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
ACS Omega. 2024 Nov 25;9(49):48149-48158. doi: 10.1021/acsomega.4c04940. eCollection 2024 Dec 10.
Sustainable poly(lactic acid) (PLA)/poly(propylene carbonate) (PPC) blends were compatibilized by the environmentally friendly epoxidized soybean oil (ESO) through the chemical reaction of epoxy functional groups on ESO with the terminated carboxyl and hydroxyl groups of PLA/PPC. The compatibilization effect of ESO was confirmed by Fourier transform infrared spectroscopy, rheological property testing, differential scanning calorimetry, and morphological observations. It was revealed that the molecular chain entanglement between PLA and PPC was significantly enhanced and the dispersed PPC phase size was decreased, which endowed the blend with high viscosity modulus, low tan δ, and great stretchability, especially for the blend containing 1.0 wt % ESO. The compatibilization effect dramatically reinforced the toughening modification of PPC on PLA, resulting in a great ductility with a fracture strain up to 187.3%, more than 20 times that of the pristine PLA, while maintaining a high strength of 44.5 MPa. Compared to the neat PLA and the PLA/PPC blend, the compatibilized blend showed a much larger draw ratio of up to 6.5 × 6.5 during biaxial stretching, producing a uniform film with balanced mechanical properties, high optical transparency, and good oxygen barrier performance. This work will be of vital importance for guiding the preparation of PLA-based films with superior comprehensive properties.
通过环保型环氧化大豆油（ESO），使聚乳酸（PLA）/聚碳酸亚丙酯（PPC）共混物实现可持续相容化。具体方式是ESO上的环氧官能团与PLA/PPC的端羧基和端羟基发生化学反应。通过傅里叶变换红外光谱、流变性能测试、差示扫描量热法和形态观察等手段，证实了ESO的相容化效果。结果表明，PLA与PPC之间的分子链缠结显著增强，分散的PPC相尺寸减小，这赋予了共混物高粘度模量、低损耗因子和良好的拉伸性，特别是对于含有1.0 wt% ESO的共混物。这种相容化效果极大地增强了PPC对PLA的增韧改性，使得共混物具有高达187.3%的断裂应变，呈现出良好的延展性，是原始PLA的20多倍，同时保持了44.5 MPa的高强度。与纯PLA和PLA/PPC共混物相比，相容化后的共混物在双轴拉伸过程中显示出高达6.5×6.5的更大拉伸比，制备出具有平衡机械性能、高光学透明度和良好氧气阻隔性能的均匀薄膜。这项工作对于指导制备具有优异综合性能的PLA基薄膜至关重要。
