Cellulose nanocrystals (CNCs) are an emerging nanomaterial for applications ranging from coatings and construction to adhesives and biomedical devices. Owing to their high aspect ratio, stiffness, and reinforcing potential, CNCs have shown great promise to be used in polymer nanocomposites. However, due to their inherent hydrophilicity and compatibility with polar environments, the use of CNCs in hydrophobic polymer matrices or in organic solvent-based formulations has been limited. To overcome this incompatibility, many reports on grafting polymers onto the surface of CNCs have been published over the past ten years. This review describes the recent advances in CNC surface functionalization through polymer grafting, and comprehensively covers the existing work to date. Methods including polymer “grafting to” and “grafting from” are described in detail, using polymerization techniques such as free radical, ring opening, and controlled radical polymerization. Purification and characterization of polymer-grafted CNCs, the potential for upscaling these functionalization methods, and current perspectives from academic and industrial viewpoints are presented.

纤维素纳米晶体（CNC）是一种新兴的纳米材料，其应用范围从涂料和建筑到粘合剂和生物医学设备。由于其高的纵横比，刚度和增强潜力，CNC已显示出可用于聚合物纳米复合材料的巨大希望。但是，由于它们固有的亲水性和与极性环境的相容性，在疏水性聚合物基体或基于有机溶剂的配方中，CNC的使用受到了限制。为了克服这种不兼容性，在过去的十年中，已经发表了许多关于将聚合物接枝到CNC表面的报道。这篇综述描述了通过聚合物接枝在CNC表面功能化方面的最新进展，并全面涵盖了迄今为止的现有工作。方法包括将聚合物“接枝到”和‘接枝自’中详细地描述，使用聚合技术如自由基，开环，和受控的自由基聚合。本文介绍了聚合物接枝CNC的纯化和表征，升级这些功能化方法的潜力以及当前从学术和工业角度出发的观点。