The insufficient compatibility between poly(lactic acid) (PLA) and thermoplastic polyurethane (TPU) phase leads to some disadvantages such as extrudate swell and poor mechanical properties of PLA/TPU blends. Therefore, to improve the compatibility is an essential work of modifying the blends. In this study, PLA, dicumyl peroxide (DCP), glycidyl methacrylate (GMA) and TPU were added to torque rheometer in sequence to synthesize PLA-g-TPU graft copolymer, and the synthetic products were characterized by nuclear magnetic resonance (NMR) spectroscopy and Fourier transform infrared (FTIR) spectra. Subsequently, binary blends (PLA /TPU blends) and ternary blends (PLA/TPU/PLA-g-TPU blends) were prepared via melt blending in twin screw extruder. The compatibility, the extrusion behavior, thermal stabilities and mechanical properties of binary blends and ternary blends were studied, respectively. The results showed that the graft copolymer played a crucial role in improving the compatibility of PLA/TPU blends. In comparison to binary blends, the ternary blends exhibited better extrusion behavior and higher thermal stabilities. In addition, the notched impact strength and elongation at break of blends improved under the effect of the graft copolymer. Interestingly, the tensile strength also strengthened with incorporation of the graft copolymer, which indicated that the interfacial adhesion between PLA phase and TPU phase had been enhanced.

聚乳酸（PLA）和热塑性聚氨酯（TPU）相之间的相容性不足会导致一些缺点，例如挤出物溶胀和PLA / TPU共混物的机械性能较差。因此，提高相容性是改性共混物的必不可少的工作。在这项研究中，将PLA，过氧化二枯基（DCP），甲基丙烯酸缩水甘油酯（GMA）和TPU依次添加到扭矩流变仪中，以合成PLA-g-TPU接枝共聚物，并通过核磁共振（NMR）光谱对合成产物进行表征。和傅立叶红外光谱（FTIR）。随后，通过在双螺杆挤出机中熔融共混制备二元共混物（PLA / TPU共混物）和三元共混物（PLA / TPU / PLA-g-TPU共混物）。兼容性，挤出行为，研究了二元共混物和三元共混物的热稳定性和力学性能。结果表明，接枝共聚物在改善PLA / TPU共混物的相容性方面起着至关重要的作用。与二元共混物相比，三元共混物表现出更好的挤出性能和更高的热稳定性。另外，在接枝共聚物的作用下，共混物的缺口冲击强度和断裂伸长率得到改善。有趣的是，通过接枝共聚物的加入，拉伸强度也得到了增强，这表明PLA相与TPU相之间的界面粘合性得到了增强。三元共混物表现出更好的挤出性能和更高的热稳定性。另外，在接枝共聚物的作用下，共混物的缺口冲击强度和断裂伸长率得到改善。有趣的是，通过接枝共聚物的加入，拉伸强度也得到了增强，这表明PLA相与TPU相之间的界面粘合性得到了增强。三元共混物表现出更好的挤出性能和更高的热稳定性。另外，在接枝共聚物的作用下，共混物的缺口冲击强度和断裂伸长率得到改善。有趣的是，通过接枝共聚物的加入，拉伸强度也得到了增强，这表明PLA相与TPU相之间的界面粘合性得到了增强。