Smart Materials Group, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy.
Smart Materials Group, Istituto Italiano di Tecnologia, Via Morego 30, 16163, Genoa, Italy; Instituto de Hortofruticultura Subtropical y Mediterránea "La Mayora", Universidad de Málaga-Consejo Superior de Investigaciones Científicas (IHSM, UMA-CSIC), Av. Louis Pasteur, 49, 29010, Málaga, Spain.
Carbohydr Polym. 2021 Nov 1;271:118031. doi: 10.1016/j.carbpol.2021.118031. Epub 2021 Jul 7.
Cellulose ester films were prepared by esterification of cellulose with a multibranched fluorinated carboxylic acid, "BRFA" (BRanched Fluorinated Acid), at different anhydroglucose unit:BRFA molar ratios (i.e., 1:0, 10:1, 5:1, and 1:1). Morphological and optical analyses showed that cellulose-BRFA materials at molar ratios 10:1 and 5:1 formed flat and transparent films, while the one at 1:1 M ratio formed rough and translucent films. Degrees of substitution (DS) of 0.06, 0.09, and 0.23 were calculated by NMR for the samples at molar ratios 10:1, 5:1, and 1:1, respectively. ATR-FTIR spectroscopy confirmed the esterification. DSC thermograms showed a single glass transition, typical of amorphous polymers, at -11 °C. The presence of BRFA groups shifted the mechanical behavior from rigid to ductile and soft with increasing DS. Wettability was similar to standard fluoropolymers such as PTFE and PVDF. Finally, breathability and water uptake were characterized and found comparable to materials typically used in textiles.
纤维素酯薄膜通过纤维素与多支链氟化羧酸“BRFA”（支链氟化酸）在不同的无水葡萄糖单元与 BRFA 摩尔比（即 1:0、10:1、5:1 和 1:1）进行酯化反应而制备。形态和光学分析表明，摩尔比为 10:1 和 5:1 的纤维素-BRFA 材料形成了平整透明的薄膜，而摩尔比为 1:1 的材料则形成了粗糙的半透明薄膜。通过 NMR 计算，摩尔比为 10:1、5:1 和 1:1 的样品的取代度（DS）分别为 0.06、0.09 和 0.23。ATR-FTIR 光谱证实了酯化反应的发生。DSC 热图谱显示，在-11°C 处存在单一的玻璃化转变，这是无定形聚合物的典型特征。随着 DS 的增加，BRFA 基团的存在将机械性能从刚性转变为韧性和柔软性。润湿性与 PTFE 和 PVDF 等标准氟聚合物相似。最后，对透气性和吸水性进行了表征，发现与通常用于纺织品的材料相当。
