Univ. Artois, EA 4515, Laboratoire de Génie Civil et géo-Environment (LGCgE), F-62400 Béthune, France.
Univ. Artois, UnilaSalle, Unité Transformations & Agroressources, ULR7519, F-62408 Béthune, France.
Carbohydr Polym. 2020 Apr 15;234:115912. doi: 10.1016/j.carbpol.2020.115912. Epub 2020 Jan 24.
A series of fatty acid cellulose esters (FACEs) with both various degrees of substitution (from DS = 1.7 to 3) and side chain length were obtained by grafting aliphatic acid chlorides (from C10 to C16) onto cellulose backbone, in a homogeneous LiCl/DMAc medium. These materials were characterized by Fourier Transformed InfraRed (FTIR) and Nuclear Magnetic Resonance of Proton (H NMR) spectroscopies, as well as Wide Angle X-ray Scattering (WAXS), Differential Scanning Calorimetry (DSC), mechanical analyses and chemical resistance to concentrated acid and alkali solutions. Whatever the alkyl chains length and the DS, all samples displayed a layered structure composed of a planar arrangement of parallel cellulosic backbones with fully extended flexible side chains oriented perpendicular to the planar structure without interdigitation. The alkyl chains were able to crystallize as soon as they are long enough. As the DS decreased, the plasticizing effect of the alkyl chains was less pronounced and their ability to crystallize was improved. Regarding the mechanical behavior and the chemical resistance, similar results were observed whatever the DS is.
一系列脂肪酸纤维素酯（FACEs）具有不同程度的取代度（从 DS=1.7 到 3）和侧链长度，通过将脂肪酰氯（从 C10 到 C16）接枝到纤维素主链上，在均相 LiCl/DMAc 介质中获得。这些材料通过傅里叶变换红外（FTIR）和质子核磁共振（H NMR）光谱、广角 X 射线散射（WAXS）、差示扫描量热法（DSC）、机械分析以及对浓酸和强碱溶液的化学抗性进行了表征。无论烷基链的长度和 DS 如何，所有样品都显示出由平行纤维素主链的平面排列组成的层状结构，完全伸展的柔性侧链垂直于平面结构取向，没有交错。烷基链只要足够长就能够结晶。随着 DS 的降低，烷基链的增塑作用不那么明显，它们的结晶能力得到提高。关于机械行为和化学抗性，无论 DS 如何，都观察到类似的结果。
