Aligned unidirectional PLA/bacterial cellulose nanocomposite fibre reinforced PDLLA composites
Aligned unidirectional PLA/bacterial cellulose nanocomposite fibre reinforced PDLLA composites
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DOI：
10.1016/j.reactfunctpolym.2014.09.006
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发表时间：
2014-12-01
影响因子：
5.1
通讯作者：
Bismarck, Alexander
中科院分区：
文献类型：
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作者：
Blaker, Jonny J.;Lee, Koon-Yang;Bismarck, Alexander
为了提高聚乳酸（PLA）的性能，我们已经开发了熔融纺丝技术来生产PLA/纳米纤维素复合纤维，以及一种类似于分层长丝缠绕，然后通过压缩成型来生产自增强PLA/纳米纤维素复合材料的方法。聚（L-丙交酯）（PLLA）纤维填充有2 wt.纯的和改性的细菌纤维素（BC），以改善纯PLA纤维的拉伸性能。BC增加了聚合物熔体的粘度，降低了纤维的拉伸比，导致纤维直径增加。尽管如此，应变诱导链取向由于熔融纺丝导致PLLA纤维具有增强的拉伸模量（6 GPa）和强度（127 MPa），超过单片PLLA，先前分别在1.3 GPa和61 MPa下测量。BC的存在也促进了PLA中晶体的成核和生长。我们进一步制备了具有7重量%的聚乳酸纤维，纤维素纳米晶体（CNC），其高于逾渗阈值（相当于6体积%）。将这些纤维以多个交替的受控层纺到线轴上，随后压缩模塑以产生单向自增强PLA复合材料，其由60体积%的聚乳酸纤维组成。PLLA纤维增强，7 wt.% CNC在无定形PDLLA的基质中，其本身含有7重量%的在CNC。我们观察到的粘弹性性能的改善高达175%的弯曲储能模量方面。此外，PLLA纤维增强PDLLA的失效应变记录为17%。(C)2014爱思唯尔有限公司版权所有。
In an effort to enhance the properties of polylactide (PLA), we have developed melt-spinning techniques to produce both PLA/nanocellulose composite fibres, and a method akin to layered filament winding followed by compression moulding to produce self-reinforced PLA/nanocellulose composites. Poly(L-lactide) (PLLA) fibres were filled with 2 wt.% neat and modified bacterial cellulose (BC) in an effort to improve the tensile properties over neat PLA fibres. BC increased the viscosity of the polymer melt and reduced the draw-ratio of the fibres, resulting in increased fibre diameters. Nonetheless, strain induced chain orientation due to melt spinning led to PLLA fibres with enhanced tensile modulus (6 GPa) and strength (127 MPa), over monolithic PLLA, previously measured at 1.3 GPa and 61 MPa, respectively. The presence of BC also enhanced the nucleation and growth of crystals in PLA. We further produced PLA fibres with 7 wt.% cellulose nanocrystals (CNCs), which is higher than the percolation threshold (equivalent to 6 vol.%). These fibres were spun in multiple, alternating controlled layers onto spools, and subsequently compression moulded to produce unidirectional self-reinforced PLA composites consisting of 60 vol.% PLLA fibres reinforced with 7 wt.% CNC in a matrix of amorphous PDLLA, which itself contained 7 wt.% of CNC. We observed improvements in viscoelastic properties of up to 175% in terms of storage moduli in bending. Furthermore, strains to failure for PLLA fibre reinforced PDLLA were recorded at 17%. (C) 2014 Elsevier B.V. All rights reserved.