UR1268 Biopolymères Interactions Assemblages, INRA, 44300, Nantes, France.
ROQUETTE, Rue de la Haute Loge, 62136, Lestrem, France.
Carbohydr Polym. 2019 Dec 1;225:115123. doi: 10.1016/j.carbpol.2019.115123. Epub 2019 Aug 13.
Different amounts of cellulose nanocrystals (CNCs) were added to glycerol-plasticized thermoplastic starch (TPS) to obtain bio-based nanocomposites. First, nanocomposites are prepared by extrusion and their structure is studied at different scales using WAXS (Wide Angle X-ray Scattering) and solid-state NMR (Nuclear Magnetic Resonance) for local/crystalline organization, AF4 (Asymmetrical Flow Field-Flow Fractionation) for molecular weight and chain length, and SEM (Scanning Electron Microscopy) for the morphology at a larger scale. Then, relevant mechanical properties and behavior in physiological conditions (swelling, enzymatic degradation) are characterized. The results show that the incorporation of cellulose nanocrystals up to 2.5 wt% causes a mechanical reinforcement as determined by DMTA (Dynamic Mechanical Thermal Analysis) and reduces the swelling and the enzymatic degradation of the materials compared to reference TPS. This could be linked to the formation of starch-cellulose hydrogen and hydroxyl bonds. Conversely, above 5 wt% CNC content nanocrystals seem to aggregate which in turn worsens the behavior in physiological conditions.
不同含量的纤维素纳米晶（CNC）被添加到甘油增塑的热塑性淀粉（TPS）中，以获得基于生物的纳米复合材料。首先，通过挤出制备纳米复合材料，并使用 WAXS（广角 X 射线散射）和固态 NMR（核磁共振）研究其在不同尺度下的结构，用于局部/结晶组织的 AF4（不对称流场-流分离），用于分子量和链长的 SEM（扫描电子显微镜）用于较大尺度的形态。然后，对相关的机械性能和生理条件下的行为（溶胀、酶降解）进行了表征。结果表明，与参考 TPS 相比，添加高达 2.5wt%的纤维素纳米晶会导致由 DMTA（动态机械热分析）确定的机械增强，并降低材料的溶胀和酶降解。这可能与淀粉-纤维素氢键和羟基键的形成有关。相反，在 5wt%以上的 CNC 含量下，纳米晶似乎会聚集，从而使在生理条件下的行为恶化。
