Iglesias Montes Magdalena L, Luzi Francesca, Dominici Franco, Torre Luigi, Cyras Viviana P, Manfredi Liliana B, Puglia Debora
Facultad de Ingeniería, Instituto de Investigaciones en Ciencia y Tecnología de Materiales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
Civil and Environmental Engineering Department, UdR INSTM, University of Perugia, Terni, Italy.
Front Chem. 2019 Mar 26;7:157. doi: 10.3389/fchem.2019.00157. eCollection 2019.
Poly (lactic acid) (PLA) bilayer films, containing cellulose nanocrystals (CNC) or lignin nanoparticles (LNP) and (UMB) were extruded and successfully layered by thermo-compression starting from monolayer films. Lignocellulosic nanostructures were used in PLA based film as nanofillers at 3 wt.%, while UMB was used as active ingredient (AI) at 15 wt.%. The effects of processing techniques, presence, typology and content of lignocellulosic nanoparticles have been analyzed and thermal, morphological, mechanical and optical characterization of PLA nanocomposites have been made. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectroscopy (FTIR) studies evaluated the presence of nanofillers and AI at chemical level. Bilayer formulations showed a good interfacial adhesion and improved stress at break with respect of PLA monolayers, although they were less stretchable and transparent. Data obtained from thermal, colorimetric and transparency investigations underlined that the presence of lignocellulosic nanofillers and AI in PLA monolayer and bilayer films induced relevant alterations in terms of overall color properties and thermal stability, while antioxidant activity of umbelliferone was enhanced by the addition of lignin in produced materials.
聚乳酸（PLA）双层膜，包含纤维素纳米晶体（CNC）或木质素纳米颗粒（LNP）以及伞形酮（UMB），由单层膜通过热压成功挤出并分层。木质纤维素纳米结构以3 wt.%的比例作为纳米填料用于基于PLA的薄膜中，而伞形酮则以15 wt.%的比例用作活性成分（AI）。分析了加工技术、木质纤维素纳米颗粒的存在、类型和含量的影响，并对PLA纳米复合材料进行了热、形态、机械和光学表征。此外，X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）研究在化学层面评估了纳米填料和活性成分的存在情况。双层配方显示出良好的界面粘附性，并且相对于PLA单层膜，其断裂应力有所提高，尽管它们的拉伸性和透明度较低。从热、比色和透明度研究中获得的数据强调，PLA单层膜和双层膜中木质纤维素纳米填料和活性成分的存在在整体颜色特性和热稳定性方面引起了相关变化，而在生产的材料中添加木质素增强了伞形酮的抗氧化活性。
