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以壳聚糖微粒为增强体,离子液体为纤维素溶剂,采用冷冻干燥法成功制备了壳聚糖/纤维素生物质发泡复合材料。利用SEM、XRD和TGA表征多孔复合材料微观结构、结晶性能以及热稳定性,测试了其孔隙率和吸水性能。实验结果表明:壳聚糖/纤维素多孔复合材料具有三维相互贯通的微孔结构,壳聚糖粉体有助于孔洞结构的形成,TGA结果显示纤维素多孔材料的热稳定性能得以提高。XRD结果显示纤维素经离子液体溶解再生后晶型结构由纤维素I转化为纤维素II。纤维素含量较低(≤4wt%)时,随1wt%壳聚糖粉体的加入,孔隙率明显提高。壳聚糖/纤维素多孔复合材料的力学性能随纤维素含量的增加而不断提高,而吸水性能有所下降。壳聚糖与纤维素质量比为1∶3时,壳聚糖/纤维素多孔复合材料孔隙率为72.7%,吸水率和相对保湿率分别为28.0g/g和17.6g/g,断裂强度和断裂伸长率分别为0.32 MPa和25.4%,能够作为一种优良的吸附材料用于制备高性能的医用敷料。
The chitosan / cellulose biomass foam composite was successfully prepared by freeze-drying with chitosan microparticle as reinforcement and ionic liquid as cellulose solvent. The microstructure, crystallinity and thermal stability of porous composites were characterized by SEM, XRD and TGA, and their porosity and water absorption properties were tested. The experimental results show that: the chitosan / cellulose porous composites have three-dimensional interpenetrating micropore structure, the chitosan powder contributes to the formation of the pore structure, and the TGA results show that the thermal stability of the cellulosic porous material can be improved. The results of XRD showed that cellulose was transformed into cellulose II by cellulose I after the cellulose was dissolved and regenerated by ionic liquid. When the content of cellulose is low (≤4wt%), the porosity increases obviously with the addition of1wt% chitosan powder. The mechanical properties of chitosan / cellulose porous composites increased with the increase of cellulose content, while the water absorption properties decreased. The mass ratio of chitosan to cellulose is 1: 3, the porosity of chitosan / cellulose porous composite is 72.7%, the water absorption and relative moisture retention are 28.0g / g and 17.6g / g respectively, the breaking strength and The elongation at break is 0.32 MPa and 25.4%, respectively, which can be used as an excellent adsorbent for the preparation of high performance medical dressings.