School of Chemistry & Chemical Engineering, Yangzhou University, Jiangsu 225002, PR China; Provincial Key Laboratories of Environmental Engineering & Material, Jiangsu 225002, PR China.
School of Chemistry & Chemical Engineering, Yangzhou University, Jiangsu 225002, PR China.
Carbohydr Polym. 2015 Dec 10;134:508-15. doi: 10.1016/j.carbpol.2015.08.023. Epub 2015 Aug 13.
Cellulose crystals, including microcrystalline cellulose (MCC) and nanocrystalline cellulose (NCC), were used as the fillers to prepare green composites with poly(β-hydroxybutyrate) (PHB) by melt mixing for crystallization study. The results reveal that the spherulite morphology of PHB and its composites depends highly on the crystallization temperature, evolving from bundle shaped to ring-banded and finally to irregular or zigzag textures with increase of temperature. However, the ring-banded structure is strongly affected by the presence of cellulose crystals, and the average band space decreases evidently with the addition of MCC or NCC. Compared with PHB/MCC composite, PHB/NCC composite shows degraded spherulite structure with smaller band space and higher flocculation level of peak-to-valley height because of stronger unbalanced stresses in this system. Besides, cellulose crystals can act as good heterogeneous nucleating agent to accelerate the crystallization of PHB, which is further confirmed by the polarized optical microscopy observations and the kinetic analyses.
纤维素晶体，包括微晶纤维素（MCC）和纳米纤维素晶体（NCC），被用作填充剂，通过熔融混合制备聚（β-羟基丁酸酯）（PHB）的绿色复合材料，用于结晶研究。结果表明，PHB 及其复合材料的球晶形态高度依赖于结晶温度，随着温度的升高，从束状演化到环带状，最后到不规则或锯齿状结构。然而，环带结构受到纤维素晶体的强烈影响，随着 MCC 或 NCC 的添加，平均带间距明显减小。与 PHB/MCC 复合材料相比，由于该体系中存在更强的不平衡应力，PHB/NCC 复合材料的球晶结构降解，带间距更小，峰谷高度的团聚程度更高。此外，纤维素晶体可以作为良好的异质成核剂来加速 PHB 的结晶，这可以通过偏光显微镜观察和动力学分析进一步证实。
