Zielińska Daria, Szentner Kinga, Waśkiewicz Agnieszka, Borysiak Sławomir
Institute of Chemical Technology and Engineering, Poznan University of Technology, Berdychowo 4, 60965 Poznan, Poland.
Department of Chemistry, Faculty of Forestry and Wood Technology, Poznan University of Life Sciences, Wojska Polskiego 75, 60625 Poznan, Poland.
Materials (Basel). 2021 Apr 22;14(9):2124. doi: 10.3390/ma14092124.
In the last few years, the scientific community around the world has devoted a lot of attention to the search for the best methods of obtaining nanocellulose. In this work, nanocellulose was obtained in enzymatic reactions with strictly defined dispersion and structural parameters in order to use it as a filler for polymers. The controlled enzymatic hydrolysis of the polysaccharide was carried out in the presence of cellulolytic enzymes from microscopic fungi- and sp. It has been shown that the efficiency of bioconversion of cellulose material depends on the type of enzymes used. The use of a complex of cellulases obtained from a fungus of the genus turned out to be an effective method of obtaining cellulose of nanometric dimensions with a very low polydispersity. The effect of cellulose enzymatic reactions was assessed using the technique of high-performance liquid chromatography coupled with a refractometric detector, X-ray diffraction, dynamic light scattering and Fourier transform infrared spectroscopy. In the second stage, polypropylene composites with nanometric cellulose were obtained by extrusion and injection. It was found by means of X-ray diffraction, hot stage optical microscopy and differential scanning calorimetry that nanocellulose had a significant effect on the supermolecular structure, nucleation activity and the course of phase transitions of the obtained polymer nanocomposites. Moreover, the obtained nanocomposites are characterized by very good strength properties. This paper describes for the first time that the obtained cellulose nanofillers with defined parameters can be used for the production of polymer composites with a strictly defined polymorphic structure, which in turn may influence future decision making about obtaining materials with controllable properties, e.g., high flexibility, enabling the thermoforming process of packaging.
在过去几年中,全球科学界投入了大量精力来寻找获取纳米纤维素的最佳方法。在这项工作中,通过具有严格定义的分散和结构参数的酶促反应获得了纳米纤维素,以便将其用作聚合物的填料。多糖的受控酶促水解是在来自微观真菌的纤维素分解酶存在下进行的。结果表明,纤维素材料的生物转化效率取决于所用酶的类型。使用从属真菌获得的纤维素酶复合物被证明是获得具有非常低多分散性的纳米尺寸纤维素的有效方法。使用高效液相色谱结合折光率检测器、X射线衍射、动态光散射和傅里叶变换红外光谱技术评估纤维素酶促反应的效果。在第二阶段,通过挤出和注塑获得了具有纳米纤维素的聚丙烯复合材料。通过X射线衍射、热台光学显微镜和差示扫描量热法发现,纳米纤维素对所得聚合物纳米复合材料的超分子结构、成核活性和相变过程有显著影响。此外,所得纳米复合材料具有非常好的强度性能。本文首次描述了所获得的具有确定参数的纤维素纳米填料可用于生产具有严格定义的多晶型结构的聚合物复合材料,这反过来可能会影响未来关于获得具有可控性能(例如高柔韧性,能够进行包装热成型工艺)材料的决策。