3种生物纤维素膜的结构与性能

Structure and properties of three kinds of bacterial cellulose films

采用无风电热干燥、真空干燥和冷冻干燥等3种方式处理生物纤维素凝胶膜,制备了3种生物纤维素膜(BC1、BC2、BC3),然后研究了其SEM形貌、IR、XRD和物理机械性能、孔隙率、吸液量、保液量、水蒸气透过率、透光率和热稳定性能。结果表明BC1的表面致密,BC2的孔洞和裂缝较BC1明显,BC3具有层状和孔洞结构。3种BC膜的晶型都是纤维素Ⅰ,但是BC1的结晶度为73.9%,BC2的结晶度为63.8%,BC3的结晶度为58.2%。BC1的弹性模量、断裂强度、透光率和热稳定性最好,BC3的孔隙率、吸液量、保液量和透湿性能最优异,BC2的各项性能处于BC1和BC3之间。

Three kinds of bacterial cellulose films(BC1,BC2,BC3) were prepared by different drying methods,which included electrothermal drying without hot-air,vacuum drying and freeze drying.The structure of bacterial cellulose films was characterized using scanning electron microscopy(SEM),infrared spectroscopy(IR) and X-ray diffraction(XRD).Physical and mechanical properties,porosity,absorbing water capacity,preserving water capacity,water vapor penetration rate,transparency and thermal stability of BC films were tested.The results showed that the surface of BC1 films is uniform and dense,cavities and cracks configurations exist in BC2 films,and cavities and layer structures are observed in BC3 films.All the three kinds of bacterial cellulose films demonstrate a crystalline form of cellulose I,but the crystallinity of BC1 films,BC2 films and BC3 films were 73.9%,63.8% and 58.2%.Of these three kinds of BC films,elastic modulus,breaking strength,transparency and thermal stability of BC1 films were best,porosity,absorbing water capacity,preserving water capacity,water vapor penetration rate of BC3 films were the best,and properties of BC2 films were between those of BC,and BC3.