Changchun University of Technology, Changchun 130012, China; Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Int J Biol Macromol. 2019 Apr 15;127:415-424. doi: 10.1016/j.ijbiomac.2019.01.068. Epub 2019 Jan 16.
The super toughed poly(l-lactic acid) (PLLA) blends with various content of Ethylene/butyl methacrylate/Glycidyl Methacrylate Terpolymer (GEBMA) were prepared by melt compounding. The blend was an immiscible system but had good compatibility due to the chemical reaction between the epoxy groups of GEBMA and the end group of PLLA during the blending process. The addition of GEBMA suppressed the cold crystallization and non-isothermal melt crystallization of PLLA. GEBMA was a very effective toughening agent for PLLA. The addition of only 15 wt% GEBMA, the elongation at break and impact strength of the blend were significantly improved compared to neat PLLA, which were 63 and 18 times that of neat PLLA, respectively. Scanning electron microscopy (SEM) images of the impact fracture surfaces of the blends showed a large amount of cavities and plastic deformation in the blend, which induced energy dissipation and therefore led to the improvement in toughness of the PLLA/GEBMA blends. For the PLLA/GEBMA blown films, the addition of GEBMA significantly improved the flexibility of PLLA/GEBMA blown film. The tear strength reached a maximum of 143.5 kN/m in the machine direction (MD) and 166.7 kN/m in the transverse direction (TD). Moreover, the biodegradation of PLLA was enhanced after blends preparation.
采用熔融共混法制备了不同含量的乙烯/丁基甲基丙烯酸酯/甲基丙烯酸缩水甘油酯三元共聚物（GEBMA）增韧聚 L-乳酸（PLLA）共混物。共混物为不相容体系，但由于 GEBMA 的环氧基团与 PLLA 端基在共混过程中的化学反应，共混物具有良好的相容性。GEBMA 的加入抑制了 PLLA 的冷结晶和非等温熔融结晶。GEBMA 是 PLLA 的非常有效的增韧剂。与纯 PLLA 相比，仅添加 15wt%的 GEBMA，共混物的断裂伸长率和冲击强度显著提高，分别达到纯 PLLA 的 63 倍和 18 倍。共混物冲击断裂面的扫描电子显微镜（SEM）图像显示，大量空穴和塑性变形存在于共混物中，导致能量耗散，从而提高了 PLLA/GEBMA 共混物的韧性。对于 PLLA/GEBMA 吹塑薄膜，GEBMA 的加入显著提高了 PLLA/GEBMA 吹塑薄膜的柔韧性。在机器方向（MD）上，拉伸强度达到最大值 143.5 kN/m，在横向（TD）上达到 166.7 kN/m。此外，共混物制备后，PLLA 的生物降解能力增强。
