School of Chemistry and Chemical Engineering, Jiangsu University of Technology, Changzhou 213001, China.
School of Chemistry and Chemical Engineering, Jiangsu University of Technology, Changzhou 213001, China.
Int J Biol Macromol. 2024 Sep;276(Pt 1):134119. doi: 10.1016/j.ijbiomac.2024.134119. Epub 2024 Aug 4.
Hydroxyl groups on the surface of cellulose nanocrystals (CNC) are modified by chemical methods, CNC and the modified CNC are used as fillers to prepare PHB/cellulose nanocomposites. The absorption peak of carbonyl group of the modified CNC (CNC-CL and CNC-LA) appears in the FT-IR spectra, which proves that the modifications are successful. Thermal stability of CNC-CL and CNC-LA is better than that of pure CNC. Pure CNC is beneficial to the nucleation of PHB, while CNC-CL and CNC-LA inhibit the nucleation of PHB. The spherulite size of PHB and its nanocomposites increases linearly over time, and the maximum growth rate of PHB spherulite exists at 90 °C. Rheological analysis shows that viscous deformation plays the dominant role in PHB, PHBC and PHBC-CL samples, while the elastic deformation is dominant in PHBC-LA. According to the rheological data, the dispersion of CNC-CL and CNC-LA in PHB is better than that of CNC. This work demonstrates the impact of modified CNC on the crystallization and viscoelastic properties of PHB. Moreover, the interface enhancement effect of modified CNC on PHB/CNC nanomaterials is revealed from the crystallization and rheology perspectives.
纤维素纳米晶体（CNC）表面的羟基基团通过化学方法进行修饰，然后将 CNC 和改性 CNC 用作填充剂来制备 PHB/纤维素纳米复合材料。FT-IR 光谱中出现了改性 CNC（CNC-CL 和 CNC-LA）中羰基基团的吸收峰，证明了修饰的成功。CNC-CL 和 CNC-LA 的热稳定性优于纯 CNC。纯 CNC 有利于 PHB 的成核，而 CNC-CL 和 CNC-LA 则抑制 PHB 的成核。PHB 及其纳米复合材料的球晶尺寸随时间呈线性增加，PHB 球晶的最大生长速率出现在 90°C。流变分析表明，在 PHB、PHBC 和 PHBC-CL 样品中，粘性变形起主导作用，而在 PHBC-LA 中，弹性变形起主导作用。根据流变数据，CNC-CL 和 CNC-LA 在 PHB 中的分散性优于 CNC。这项工作展示了改性 CNC 对 PHB 的结晶和粘弹性能的影响。此外，从结晶和流变学的角度揭示了改性 CNC 对 PHB/CNC 纳米材料的界面增强效应。
