Gismatulina Yulia A, Budaeva Vera V
Bioconversion Laboratory, Institute for Problems of Chemical and Energetic Technologies, Siberian Branch of the Russian Academy of Sciences (IPCET SB RAS), Biysk 659322, Russia.
Polymers (Basel). 2024 Apr 23;16(9):1183. doi: 10.3390/polym16091183.
Cellulose nitrates (CNs)-blended composites based on celluloses of bacterial origin (bacterial cellulose (BC)) and plant origin (oat-hull cellulose (OHC)) were synthesized in this study for the first time. Novel CNs-blended composites made of bacterial and plant-based celluloses with different BC-to-OHC mass ratios of 70/30, 50/50, and 30/70 were developed and fully characterized, and two methods were employed to nitrate the initial BC and OHC, and the three cellulose blends: the first method involved the use of sulfuric-nitric mixed acids (MAs), while the second method utilized concentrated nitric acid in the presence of methylene chloride (NA + MC). The CNs obtained using these two nitration methods were found to differ between each other, most notably, in viscosity: the samples nitrated with NA + MC had an extremely high viscosity of 927 mPa·s through to the formation of an immobile transparent acetonogel. Irrespective of the nitration method, the CN from BC (CN BC) was found to exhibit a higher nitrogen content than the CN from OHC (CN OHC), 12.20-12.32% vs. 11.58-11.60%, respectively. For the starting BC itself, all the cellulose blends of the starting celluloses and their CNs were detected using the SEM technique to have a reticulate fiber nanostructure. The cellulose samples and their CNs were detected using the IR spectroscopy to have basic functional groups. TGA/DTA analyses of the starting cellulose samples and the CNs therefrom demonstrated that the synthesized CN samples were of high purity and had high specific heats of decomposition at 6.14-7.13 kJ/g, corroborating their energy density. The CN BC is an excellent component with in-demand energetic performance; in particular, it has a higher nitrogen content while having a stable nanostructure. The CN BC was discovered to have a positive impact on the stability, structure, and energetic characteristics of the composites. The presence of CN OHC can make CNs-blended composites cheaper. These new CNs-blended composites made of bacterial and plant celluloses are much-needed in advanced, high-performance energetic materials.
本研究首次合成了基于细菌来源纤维素（细菌纤维素，BC）和植物来源纤维素（燕麦壳纤维素，OHC）的硝酸纤维素（CNs）共混复合材料。制备了具有70/30、50/50和30/70不同BC与OHC质量比的由细菌和植物基纤维素制成的新型CNs共混复合材料，并对其进行了全面表征，采用两种方法对初始BC和OHC以及三种纤维素共混物进行硝化：第一种方法是使用硫酸 - 硝酸混合酸（MAs），而第二种方法是在二氯甲烷存在下使用浓硝酸（NA + MC）。发现使用这两种硝化方法获得的CNs彼此不同，最明显的是在粘度方面：用NA + MC硝化的样品具有极高的粘度，达到927 mPa·s，直至形成不流动的透明丙酮凝胶。无论硝化方法如何，发现来自BC的CN（CN BC）的氮含量高于来自OHC的CN（CN OHC），分别为12.20 - 12.32%和11.58 - 11.60%。对于起始BC本身，使用扫描电子显微镜（SEM）技术检测到起始纤维素及其CNs的所有纤维素共混物均具有网状纤维纳米结构。使用红外光谱检测纤维素样品及其CNs具有基本官能团。对起始纤维素样品及其CNs的热重分析（TGA）/差示热分析（DTA）表明，合成的CN样品纯度高，在6.
