Smart Materials Group, Istituto Italiano di Tecnologia, Via Morego, 30, Genoa16163, Italy.
ACS Appl Mater Interfaces. 2022 Oct 19;14(41):46920-46931. doi: 10.1021/acsami.2c10965. Epub 2022 Oct 5.
Highly stretchable biobased and biodegradable agricultural mulch films based on polylactic acid (PLA) and 10, 20, or 30 wt % various nonedible vegetable wastes such as spinach stems (SS), tomato pomace (TP), and cocoa shells (CS) are prepared and characterized in this work. The results demonstrate that appropriate PLA plasticization and vegetable waste addition allow for obtaining films suitable for mulching with tensile strengths in the 10-24 MPa range and elongations at break up to 460%, depending on the kind and amount of vegetable waste incorporated. Additionally, the developed mulches show low water solubility (1-15 wt %) and moisture content (1-3 wt %) with a water vapor permeability of up to 3 × 10 g s m Pa, similar to that of Mater-Bi. In addition, the type of vegetable waste added as filler were demonstrated to significantly affect not only the films' mentioned properties but also their biodegradability. For instance, films prepared with 20 wt % SS were demonstrated to improve PLA soil biodegradability, which increased from 0 to 38 wt % for PLA composites after 6 months of a soil burial experiment. Lastly, the developed composites contain different amounts of plant micro- and macronutrients, indicating their potential as fertilizers. The results found in this work represent a sustainable, fully biobased alternative to other mulches already in the market.
本文制备并研究了基于聚乳酸（PLA）和 10、20 或 30wt%不同非食用蔬菜废物（如菠菜茎（SS）、番茄渣（TP）和可可壳（CS））的高拉伸性、生物基和可生物降解的农业覆盖薄膜。结果表明，适当的 PLA 塑化和蔬菜废物添加可以获得适合覆盖的薄膜，其拉伸强度在 10-24MPa 范围内，断裂伸长率高达 460%，具体取决于所添加的蔬菜废物的种类和数量。此外，所开发的覆盖薄膜具有低水溶性（1-15wt%）和低水分含量（1-3wt%），水蒸气透过率高达 3×10-4g s m Pa，与 Mater-Bi 相似。此外，作为填料添加的蔬菜废物的类型不仅显著影响薄膜的上述性能，还显著影响其生物降解性。例如，添加 20wt%SS 的薄膜被证明可以提高 PLA 的土壤生物降解性，在土壤掩埋实验 6 个月后，PLA 复合材料的生物降解性从 0 增加到 38wt%。最后，所开发的复合材料含有不同数量的植物微量和常量营养素，表明它们具有作为肥料的潜力。本文的研究结果为市场上现有的其他覆盖薄膜提供了一种可持续的、完全基于生物的替代方案。
