Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China; College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
College of Material Engineering, North China Institute of Aerospace Engineering, Langfang 065000, China.
Int J Biol Macromol. 2022 Nov 30;221:278-287. doi: 10.1016/j.ijbiomac.2022.08.121. Epub 2022 Aug 26.
The challenge of dispersing nanocellulose in hydrophobic polymers such as polylactic acid (PLA) still obstacles the further application of cellulose nanocomposites. An environment-friendly and facile wet-shearing pretreatment strategy without using any organic solvent was developed in this work. Silane modified lignocellulose nanofiber (SLCNF) was pre-dispersed into PLA by wet-shearing pretreatment, followed by extrusion process and the SLCNF could be dispersed extremely well in PLA matrices. SLCNF formed a crosslinked network and had an improved compatibility, which improved the mechanical and thermal properties of PLA composites. The tensile strength, elongation at break and thermal deformation temperature of the composites were increased by 12.6 %, 32.4 % and 9.1 °C, respectively. Moreover, SLCNF promoted the crystallization of PLA as a heterogeneous nucleating agent and the crystallinity was increased by about 40 %. This study provides an effective way to disperse nanocellulose in polymer matrix with high efficiency to enhance polymer-based composites.
在疏水性聚合物（如聚乳酸（PLA））中分散纳米纤维素仍然是纤维素纳米复合材料进一步应用的障碍。本工作开发了一种环保且简便的无需使用任何有机溶剂的湿磨预处理策略。通过湿磨预处理，预先将硅烷改性的木质纤维素纳米纤维（SLCNF）分散到 PLA 中，然后进行挤出工艺，SLCNF 可以极好地分散在 PLA 基体中。SLCNF 形成了交联网络，具有改善的相容性，从而提高了 PLA 复合材料的力学和热性能。复合材料的拉伸强度、断裂伸长率和热变形温度分别提高了 12.6%、32.4%和 9.1°C。此外，SLCNF 作为异相成核剂促进了 PLA 的结晶，结晶度提高了约 40%。本研究提供了一种有效方法，可高效地将纳米纤维素分散在聚合物基体中，以增强聚合物基复合材料。
