Tailoring poly(lactic acid) for packaging applications via the production of fully bio-based in situ microfibrillar composite films
Tailoring poly(lactic acid) for packaging applications via the production of fully bio-based in situ microfibrillar composite films
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DOI：
10.1016/j.cej.2016.09.130
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发表时间：
2017-01-15
影响因子：
15.1
通讯作者：
Park, Chul B.
中科院分区：
文献类型：
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作者：
Kakroodi, Adel Ramezani;Kazemi, Yasamin;Park, Chul B.
尽管聚乳酸（PLA）具有许多优点，但其作为包装材料的广泛商业化受到其许多缺点的阻碍，例如低熔体弹性、缓慢结晶和低气体阻隔性能。在这项开创性的研究中，我们引入了原位微纤化工艺的概念，作为一种高效、经济且环保的技术，用于增强聚乳酸薄膜的性能。通过快速简单的熔融挤出和热拉伸工艺制备了以聚乳酸（PLA）为基体、不同种类（石油基和生物基）聚酰胺（PA）微纤为基体的原位微纤复合材料（MFC）。形态学观察表明分散的PA相成功地转化为直径近200 nm的非常长且灵活的微纤维形状。剪切流变学研究表明，与纯聚乳酸相比，MFC的熔体弹性有显着改善。微纤化后PLA的结晶动力学也得到明显改善，这归因于微纤的异相结晶成核效应。气体渗透率的测量证实，在氧气的传输速率（OTR）和水蒸气传输速率（WVTR）的PLA膜的微纤化过程后，然后等温退火的大幅减少。与PLA相比，MFC还显示出显著改善的拉伸性能。(C)2016爱思唯尔B.V.保留所有权利。
Despite its many advantages, poly(lactic acid)'s (PLA's) vast commercialization as a packaging material has been hindered by its numerous drawbacks such as low melt elasticity, slow crystallization, and low gas barrier properties. In this pioneering research, we introduce the concept of in situ microfibrillation process as an efficient, cost-effective, and environmentally friendly technique for the enhancement of PLA films' properties. In situ microfibrillar composites (MFCs) with PLA matrix and different (petroleum and biobased) polyamide (PA) microfibrils were produced via a fast and simple melt extrusion and hot stretching process. Morphological observations demonstrated the successful transformation of the dispersed PA phase into very long and flexible microfibrillar shapes with diameters of nearly 200 nm. Shear rheological investigations proved that the MFCs had dramatically improved melt elasticities compared with the pure PLA. The crystallization kinetics of the PLA was also significantly improved after the microfibrillation process which was attributed to the heterogeneous crystal nucleation effects of the microfibrils. Gas permeability measurements confirmed substantial reductions in the oxygen transmission rate (OTR) and water vapor transmission rate (WVTR) of the PLA film after the microfibrillation process followed by isothermal annealing. The MFCs also showed significantly improved tensile properties in comparison with the PLA. (C) 2016 Elsevier B.V. All rights reserved.