'Materials + Technology' Group, Engineering School of Gipuzkoa. Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Pza. Europa 1., 20018 Donostia - San Sebastián, Spain.
Department of Cellular Biology and Histology, Faculty of Medicine and Odontology, University of the Basque Country (UPV/EHU), B. Sarriena, s/n 48940, Leioa-Bizkaia, Spain.
Carbohydr Polym. 2019 Jul 15;216:86-96. doi: 10.1016/j.carbpol.2019.04.010. Epub 2019 Apr 3.
Water-activated shape memory bacterial cellulose/polyurethane nanocomposites were prepared by the immersion of bacterial cellulose (BC) wet membranes into waterborne polyurethane (WBPU) dispersions for different times. The high affinity between the hydrophilic BC and water stable polyurethane led to the coating and embedding of the BC membrane into the WBPU, facts that were confirmed by FTIR, SEM and mechanical testing of the nanocomposites. The mechanical performance of the nanocomposites resulted enhanced with respect to the neat WBPU, confirming the reinforcing effect of the BC membrane. An improvement of the shape fixity ability and faster recovery process with the presence of BC was observed. In 3 min, the nanocomposite with highest BC content recovered the 92.8 ± 6.3% of the original shape, while the neat WBPU only recovered the 33.4 ± 9.6%. The obtained results indicated that 5 min of impregnation time was enough to obtain nanocomposites with improved mechanical performance and fast shape recovery for potential biomedical applications. The present work provides an approach for developing environmentally friendly and biocompatible BC/polyurethane based materials with enhanced mechanical and shape memory properties.
水激活形状记忆细菌纤维素/聚氨酯纳米复合材料通过将细菌纤维素（BC）湿膜浸入水性聚氨酯（WBPU）分散体中不同时间来制备。高亲水性 BC 与水稳定型聚氨酯之间的高亲和力导致 BC 膜涂覆和嵌入 WBPU 中，这一事实通过 FTIR、SEM 和纳米复合材料的机械测试得到了证实。纳米复合材料的机械性能相对于纯 WBPU 得到了提高，证实了 BC 膜的增强效果。观察到存在 BC 时，形状固定能力得到提高，恢复过程更快。在 3 分钟内，BC 含量最高的纳米复合材料恢复了原始形状的 92.8±6.3%，而纯 WBPU 仅恢复了 33.4±9.6%。所得结果表明，5 分钟的浸渍时间足以获得具有增强机械性能和快速形状恢复的纳米复合材料，可用于潜在的生物医学应用。本工作为开发具有增强的机械和形状记忆性能的环保和生物相容的 BC/聚氨酯基材料提供了一种方法。
