Zhu Jian, Kumar Anil, Hu Pin, Habel Christoph, Breu Josef, Agarwal Seema
Macromolecular Chemistry II Bavarian Polymer Institute University of Bayreuth Universitätsstraße 30 Bayreuth 95440 Germany.
Bavarian Polymer Institute and Inorganic Chemistry University of Bayreuth Universitätsstraße 30 Bayreuth 95440 Germany.
Glob Chall. 2020 May 27;4(9):2000030. doi: 10.1002/gch2.202000030. eCollection 2020 Sep.
Research on biodegradable polymers with the intention of fast, complete degradation in industrial compost (i-compost) for organic recyclability is paramount to identifying solutions to the problem of excessive plastic waste originating specifically from packaging. Conventional biodegradable polymers, such as polylactide (PLA), are far from optimum for this application due to the poor gas barrier properties and slow degradation. In the paper, a new concept (triggered degradation by delayering) is shown in which exfoliated, self-assembled sodium-hectorite (Hec) arranged in a layer-by-layer manner alternating with electrospun hot-pressed PLA provides strong gas barrier properties at high humidity and simultaneously accelerates the degradation of PLA, as tested in an enzymatic solution and i-compost. A thin composite film (thickness 56 µm) shows a tensile strength and modulus 58 and 2000 MPa, respectively, whereas oxygen permeability is as low as 0.0064 cm cm m day bar. Furthermore, the delayering of the composite film by swelling of Hec layer led to accelerated degradation of PLA, as shown in detail by enzymatic and compost degradation. Since such concepts for enhanced degradability are urgently needed for sustainable utilization of biodegradable polymers in plastic waste management, the present work is an important step ahead.
旨在实现快速、完全降解以用于工业堆肥（i - 堆肥）从而进行有机回收利用的可生物降解聚合物研究，对于确定专门针对源自包装的过量塑料垃圾问题的解决方案至关重要。传统的可生物降解聚合物，如聚乳酸（PLA），由于其较差的气体阻隔性能和缓慢的降解速度，远非该应用的最佳选择。本文展示了一种新概念（通过分层引发降解），其中以逐层方式排列的剥离自组装钠锂蒙脱石（Hec）与电纺热压PLA交替排列，在高湿度下具有强大的气体阻隔性能，同时加速了PLA在酶溶液和i - 堆肥中的降解。一种薄复合膜（厚度56 µm）的拉伸强度和模量分别为58和2000 MPa，而氧气透过率低至0.0064 cm³ cm⁻² m⁻¹ day⁻¹ bar⁻¹。此外，Hec层的溶胀导致复合膜分层，从而加速了PLA的降解，酶解和堆肥降解对此进行了详细展示。由于在塑料垃圾管理中可持续利用可生物降解聚合物迫切需要这种提高降解性的概念，目前的工作是向前迈出的重要一步。
