Cellulose nanocrystals (CNCs) were surface-modified using immobilized lipase (Novozyme 435) to catalyze the formation of laurate ester groups on the CNC surface and thus facilitate homogeneous dispersion within a poly(lactic acid) (PLA) matrix. Results of dynamic contact angle measurement revealed that the modified CNCs (CNC-LAA) presented greater hydrophobicity than their CNC controls. FT-IR, ¹³C-NMR, XRD, and TGA were used to characterize the structure and stability of the CNCs before and after modification. PLA reinforced with the modified CNCs were prepared, and the effect on mechanical properties was studied. SEM micrographs suggested uniform dispersion of modified CNCs throughout the PLA matrix at a maximum 1 wt% loading, which was found to be the optimal loading level. The CNC-LAA were able to achieve a 0.4 maximum degree of substitution. DSC indicated enhanced crystallization of PLA chains due to the inclusion of CNC-LAA, indicating that the nanofillers behaved as nucleating agents and also revealed improved compatibility. Tensile strength tests showed slightly improved mechanical properties for breaking strength and elongation at breakage.

使用固定化的脂肪酶（Novozyme 435）对纤维素纳米晶体（CNC）进行表面修饰，以催化在CNC表面形成月桂酸酯基团，从而促进聚乳酸（PLA）基质内的均匀分散。动态接触角测量结果表明，改进的CNCs（CNC-LAA）比其CNC控件具有更大的疏水性。红外，¹³C-NMR，XRD和TGA用于表征改性前后CNC的结构和稳定性。制备了改性CNC增强的PLA，研究了其对力学性能的影响。SEM显微照片表明，改性的CNC在最大1 wt％的负载下均匀分散在整个PLA基质中，这被认为是最佳的负载水平。CNC-LAA能够达到0.4的最大取代度。DSC表明由于加入了CNC-LAA，PLA链的结晶增强，这表明纳米填料起到成核剂的作用，并且还显示出改善的相容性。拉伸强度测试表明，断裂强度和断裂伸长率的机械性能略有改善。