Fu Ling, Jiang Long, Xing Qingtao, Li Tan, Shen Zhiquan, Dan Yi, Huang Yun
State Key Laboratory of Polymer Materials Engineering of China (Sichuan University), Polymer Research Institute of Sichuan University, No.24 South Section 1, Yihuan Road, Chengdu 610065, China.
Hainan Shiner Industrial Co., Ltd, 18 North Guangfu Road, Shiziling Industrial Park, Haikou National Hi-tech Zone, Haikou, Hainan, China.
Int J Biol Macromol. 2023 Oct 1;250:126235. doi: 10.1016/j.ijbiomac.2023.126235. Epub 2023 Aug 9.
The present work tried to solve the compatibility and dispersion problems of industrial grade graphene oxide (GO) mixing with polylactide (PLA) by melt processing for practical application. PLA was grafted on the GO using the silane coupling agent (KH560) as "bridge" by in-situ melting reaction to improve the compatibility. For better compatibility and dispersion, poly(ᴅ-lactide) (PDLA) was grafted on GO (D-G) to form stereocomplex crystallites with poly(ʟ-lactide) (PLLA) to enhance the interaction between GO and PLLA matrix. By biaxial stretching, the PLLA and GO composite films were prepared. Results show that GO was seriously aggregated in the film containing GO without PLA grafting (PLLA/L/G) and the average size of aggregated GO was about 19.5 μm. PLA grafting decreased the aggregated GO size, so that the films containing L-G or D-G presented better dispersion. The film containing 5 % D-G (PLLA/D-G) exhibited the smallest average size of aggregated GO, about 12.7 μm. Compared with neat PLLA film, PLLA/L/G film presented worse tensile properties due to serious aggregation of GO. While, PLLA/D-G film presented the best tensile performance that tensile strength and elongation at break reached 120 MPa and 107 %, respectively.
本工作试图通过熔融加工解决工业级氧化石墨烯（GO）与聚乳酸（PLA）混合的相容性和分散性问题，以实现实际应用。通过原位熔融反应，以硅烷偶联剂（KH560）作为“桥梁”，将PLA接枝到GO上，以提高相容性。为了获得更好的相容性和分散性，将聚（D-丙交酯）（PDLA）接枝到GO（D-G）上，与聚（L-丙交酯）（PLLA）形成立体复合微晶，以增强GO与PLLA基体之间的相互作用。通过双轴拉伸制备了PLLA与GO的复合薄膜。结果表明，在未接枝PLA的含GO薄膜（PLLA/L/G）中，GO严重团聚，团聚的GO平均尺寸约为19.5μm。PLA接枝减小了团聚的GO尺寸，因此含L-G或D-G的薄膜表现出更好的分散性。含5%D-G的薄膜（PLLA/D-G）团聚的GO平均尺寸最小，约为12.7μm。与纯PLLA薄膜相比，由于GO的严重团聚，PLLA/L/G薄膜的拉伸性能较差。而PLLA/D-G薄膜表现出最佳的拉伸性能，拉伸强度和断裂伸长率分别达到120MPa和107%。
