Abstract We report the synthesis and characterization of ultra-tough polylactide-based ionic nanocomposites via melt-blending of commercial polylactide (PLA), imidazolium-functionalized poly(ethylene glycol)-based polyurethane (im-PU) and surface-modified sulfonated silica nanoparticles (SiO2–SO3H) using extrusion techniques. The proximity of bulky pendant imidazolium cationic sites attached onto the highly functionalized polyurethane to the anionic sulfonate groups at the silica nanoparticle surface readily allow maximizing dynamic ionic interactions within the resulting PLA-based materials. This new design leads to a unique property profile that combines ultra-toughness (no break) and ductility (up to 150%), without critical loss of stiffness as well as improved thermal stability (up to 40 °C higher compared to neat PLA). In addition, we present a detailed mechanistic study aiming at elucidating the energy-dissipative toughening in these PLA/im-PU/SiO2–SO3H blends under quasi-static and high-speed loadings (ca. impact, tensile, 3-points bending). Relying on Small-Angle X-Ray Scattering (SAXS), creep and rheological measurements, a toughening mechanism is finally proposed to account for the impact behavior of the resulting ionic nanocomposites.

中文翻译：

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超韧聚乳酸基离子纳米复合材料的机理研究

摘要 我们报告了通过熔融共混商业聚丙交酯 (PLA)、咪唑鎓官能化聚 (乙二醇) 基聚氨酯 (im-PU) 和表面改性磺化二氧化硅纳米粒子合成和表征超韧聚丙交酯基离子纳米复合材料。 (SiO2–SO3H) 使用挤压技术。附着在高度官能化聚氨酯上的庞大的悬垂咪唑鎓阳离子位点与二氧化硅纳米颗粒表面的阴离子磺酸盐基团的接近很容易使所得 PLA 基材料内的动态离子相互作用最大化。这种新设计产生了一种独特的性能特征，结合了超韧性（无断裂）和延展性（高达 150%），没有严重的刚度损失，并提高了热稳定性（与纯 PLA 相比，热稳定性最高可达 40 °C） . 此外，我们提出了一项详细的机理研究，旨在阐明这些 PLA/im-PU/SiO2-SO3H 混合物在准静态和高速载荷（例如冲击、拉伸、3 点弯曲）下的能量耗散增韧。依靠小角 X 射线散射 (SAXS)、蠕变和流变测量，最终提出了一种增韧机制来解释所得离子纳米复合材料的冲击行为。