One-step modification and nanofibrillation of microfibrillated cellulose for simultaneously reinforcing and toughening of poly(ε-caprolactone)
One-step modification and nanofibrillation of microfibrillated cellulose for simultaneously reinforcing and toughening of poly(ε-caprolactone)
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DOI：
10.1016/j.compscitech.2017.10.029
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发表时间：
2018-03-22
影响因子：
9.1
通讯作者：
Fu, Qiang
中科院分区：
文献类型：
--
作者：
Deng, Sha;Ma, Jinrui;Fu, Qiang
利用纤维素纤维作为聚己内酯(PCL)的增强体已得到了广泛的研究，以制备具有更高力学性能的可完全生物降解复合材料，但遗憾的是，强度的提高总是以牺牲韧性为代价的。在目前的工作中，我们开发了一种有效的方法来制备聚己内酯/功能化纤维素纳米纤维(PCL/f-NFC)纳米复合材料，该复合材料具有强韧性。以微纤化纤维素(MFC)为原料，通过球磨产生的机械作用和化学作用的协同作用，一步合成了规模化的f-NFC。具有纳米尺度和可剪裁疏水性的f-NFC与PCL具有良好的相容性，使得f-NFC与PCL之间具有较强的界面相互作用，并在PCL中具有良好的分散性。当f-NFC含量为0.1wt%时，复合材料的拉伸强度有了显着提高，接近100%，断裂伸长率提高了68%。由于表面性质和纤维尺寸都会影响复合材料的性能，因此在PCL中还加入了原始MFC、功能化MFC(f-MFC)和未疏水改性的纤维素纳米纤维(NFC)，进行了系统的对比研究，找出了影响复合材料性能的主要因素。结果表明，在纤维含量较低的情况下，表面改性起主导作用，而在纤维含量较高的情况下，更有利于纳米尺度的形成。最重要的是，表面改性和纳米尺度的协同效应显著提高了各种纤维含量范围内的拉伸性能。(C)2017爱思唯尔有限公司。保留所有权利。
Extensive efforts have been devoted to utilize cellulose fibers as reinforcement for poly(epsilon-caprolactone) (PCL) to prepare fully biodegradable composites with enhanced mechanical properties, but unfortunately the improvement of strength is always at the sacrifice of toughness. In the current work, we have developed an efficient way to prepare poly(epsilon-caprolactone)/functionalized cellulose nanofibers (PCL/f-NFC) nanocomposite, which is both strong and ductile. Large scale f-NFC was produced from microfibrillated cellulose (MFC) in one step through the synergy of mechanical and chemical actions derived from ball milling. The f-NFC with nanosized scale and tailored hydrophobicity is compatible with PCL, which leads to strong interfacial interaction between f-NFC and PCL and good dispersion of f-NFC in PCL. The tensile strength of this bionanocomposite undergoes a remarkable enhancement nearly 100% and elongation-at-break increases by 68% with extremely low f-NFC content as 0.1 wt%. Since both surface property and fiber size affect the performance of composites, original MFC, functionalized MFC (f-MFC) and cellulose nanofibers (NFC) without hydrophobic modification are also incorporated into PCL to make a systematic comparative study to identify the dominating factor influencing the performance. The overall results suggest that surface modification plays a dominant role at low fiber content, while nano-sized scale is much more beneficial at high fiber content. Most importantly, the synergistic effect of surface modification and nano-sized scale leads to significantly improved tensile properties across a wide range of fiber content. (C) 2017 Elsevier Ltd. All rights reserved.