Improvement of mechanical and oxygen barrier properties of cellulose films by controlling drying conditions of regenerated cellulose hydrogels
Improvement of mechanical and oxygen barrier properties of cellulose films by controlling drying conditions of regenerated cellulose hydrogels
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DOI：
10.1007/s10570-012-9683-7
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发表时间：
2012-03
期刊：
影响因子：
5.7
通讯作者：
Quanling Yang;Shuji Fujisawa;Tsuguyuki Saito;A. Isogai
中科院分区：
文献类型：
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作者：
Quanling Yang;Shuji Fujisawa;Tsuguyuki Saito;A. Isogai
由纤维素/碱/尿素水溶液制备的再生纤维素膜的机械性能、热性能和氧气阻隔性能可通过控制膜的干燥条件而显著改善。通过预压，然后在压缩下真空干燥，干燥膜的拉伸强度、杨氏模量、热膨胀系数和透氧率分别达到263 MPa、7.3 GPa、10.3 ppm K− 1和0.0007 ml μm m−2day− 1 kPa −1。因此，以这种方式生产的膜显示出再生纤维素膜的最高性能，迄今为止没有报道纤维素链的取向。这些改进的性能伴随着纤维素II结晶度在预压/压真空干燥过程中从50%到62%的明显增加。同时，薄膜密度从1.45 g cm-3增加到1.57 g cm-3，平衡条件下的水分含量从14.1%降低到9.8%。因此，通过控制干燥条件，含水碱/尿素溶剂体系在制备具有高性能的新型和环境友好的纤维素膜中具有潜在的应用。
Mechanical, thermal and oxygen barrier properties of regenerated cellulose films prepared from aqueous cellulose/alkali/urea solutions can be markedly improved by controlling the drying conditions of the films. By pre-pressing followed by vacuum drying under compression, the tensile strength, Young’s modulus, coefficient of thermal expansion and oxygen permeability of the dried films reached 263 MPa, 7.3 GPa, 10.3 ppm K−1and 0.0007 ml μm m−2day−1kPa−1, respectively. Thus, films produced in this way show the highest performance of regenerated cellulose films with no orientation of cellulose chains reported to date. These improved properties are accompanied by a clear increase in cellulose II crystallinity from 50 to 62% during pre-pressing/press-vacuum drying process. At the same time, the film density increased from 1.45 to 1.57 g cm−3, and the moisture content under equilibrium conditions decreased from 14.1 to 9.8%. Hence, the aqueous alkali/urea solvent system has potential applications in producing new and environmentally friendly cellulose films with high performances through control of the drying conditions.