Avella Angelica, Telaretti Leggieri Maria Rosella, Alexakis Alexandros Efraim, Malmström Eva, Lo Re Giada
Department of Industrial and Materials Science, Chalmers University of Technology, SE-412 58 Gothenburg, Sweden.
Wallenberg Wood Science Centre, Chalmers University of Technology, Kemigården 4, SE-412 96 Gothenburg, Sweden.
ACS Appl Mater Interfaces. 2025 Jan 8;17(1):2602-2614. doi: 10.1021/acsami.4c17899. Epub 2024 Dec 23.
The full exploitation of the outstanding mechanical properties of cellulose nanofibrils (CNFs) as potential reinforcements in nanocomposite materials is limited by the poor interactions at the CNF-polymer matrix interface. Within this work, tailor-made copolymers were designed to mediate the interface between CNFs and biodegradable poly(butylene adipate--terephthalate) (PBAT), and their effect on extruded nanocomposite performance was tested. For this purpose, two well-defined amphiphilic anchor-tail diblock copolymer structures were compared, with a fixed anchor block length and a large difference in the hydrophobic tail block length. The aim was to evaluate the impact of the copolymers' chain length on the nanocomposite interface. The presence of amphiphilic diblock copolymers significantly improved the mechanical properties compared to those of PBAT nanocomposites containing unmodified CNFs. In particular, the copolymer with a longer tail was more effective for CNF-PBAT dispersion interactions, leading to a 65% increase of Young's modulus of neat PBAT, while retaining high deformability (670%). The results provide insights into the effectiveness of a waterborne third component at the CNF-matrix interface and its structure-property relationship.
纤维素纳米原纤（CNFs）作为纳米复合材料中潜在增强材料的优异机械性能，由于其与聚合物基体界面间的不良相互作用，尚未得到充分利用。在本研究中，设计了定制的共聚物来介导CNFs与可生物降解的聚（己二酸丁二醇酯-对苯二甲酸丁二醇酯）（PBAT）之间的界面，并测试了它们对挤出纳米复合材料性能的影响。为此，比较了两种结构明确的两亲性锚定-尾段二嵌段共聚物结构，其锚定嵌段长度固定，疏水尾段长度差异较大。目的是评估共聚物链长对纳米复合材料界面的影响。与含有未改性CNFs的PBAT纳米复合材料相比，两亲性二嵌段共聚物的存在显著改善了机械性能。特别是，尾段较长的共聚物对CNF-PBAT分散相互作用更有效，使纯PBAT的杨氏模量提高了65%，同时保持了较高的可变形性（670%）。这些结果为水性第三组分在CNF-基体界面的有效性及其结构-性能关系提供了见解。
