Redondo Alexandre, Jang Daseul, Korley LaShanda T J, Gunkel Ilja, Steiner Ullrich
Adolphe Merkle Institute, University of Fribourg, Chemin des Verdiers 4, 1700 Fribourg, Switzerland.
Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA.
Polymers (Basel). 2020 May 1;12(5):1021. doi: 10.3390/polym12051021.
We report the electrospinning of mechanically-tunable, cellulose nanocrystal (CNC)-reinforced polyurethanes (PUs). Using high-aspect ratio CNCs from tunicates, the stiffness and strength of electrospun PU/CNC mats are shown to generally increase. Furthermore, by tuning the electrospinning conditions, fibrous PU/CNC mats were created with either aligned or non-aligned fibers, as confirmed by scanning electron microscopy. PU/CNC mats having fibers aligned in the strain direction were stiffer and stronger compared to mats containing non-aligned fibers. Interestingly, fiber alignment was accompanied by an anisotropic orientation of the CNCs, as confirmed by wide-angle X-ray scattering, implying their alignment additionally benefits both stiffness and strength of fibrous PU/CNC nanocomposite mats. These findings suggest that CNC alignment could serve as an additional reinforcement mechanism in the design of stronger fibrous nanocomposite mats.
我们报道了机械可调的、纤维素纳米晶体（CNC）增强聚氨酯（PU）的静电纺丝。使用来自被囊动物的高长径比CNC，静电纺丝的PU/CNC垫的刚度和强度总体上显示出增加。此外，通过调整静电纺丝条件，制备出了具有排列或未排列纤维的纤维状PU/CNC垫，这通过扫描电子显微镜得以证实。与含有未排列纤维的垫相比，具有沿应变方向排列纤维的PU/CNC垫更硬且更强。有趣的是，如广角X射线散射所证实，纤维排列伴随着CNC的各向异性取向，这意味着它们的排列额外有益于纤维状PU/CNC纳米复合垫的刚度和强度。这些发现表明，CNC排列可作为设计更强纤维状纳米复合垫的一种额外增强机制。
