羧甲基纤维素-壳聚糖共混膜的性能表征

通过共混的方法制备了3种不同质量比(1∶2、1∶1、2∶1)的羧甲基纤维素-壳聚糖(CMC-CS)共混膜,利用IR和扫描电镜(SEM)对膜进行结构表征,用差示扫描量热法(DSC)考察了CMC-CS共混膜的热稳定性,研究了共混膜的均匀性、耐酸性、拉伸强度和溶胀性,并对分子间的作用机理进行探讨。结果表明,CMC与CS混合时,存在静电作用与氢键作用,生成了聚电解质复合物;在170~330℃,共混膜分子间发生降解,在217.4℃时离子键断裂,静电作用消失;经分析当CMC与CS比例为1∶1时,膜性能最好,共混膜的静电作用最大,拉伸强度可达34.44 MPa,比CS单膜拉伸强度提高了64.47%;CMC的加入,使得酸性适用范围下限由CS膜的pH值5降至4,在pH值6中浸泡一段时间后,测得拉伸强度为25.71 MPa;CMC-CS膜的吸水溶胀性显著降低。

Characterization of Chitosan-carboxymethyl Cellulose Blended Membrane

Carboxymethyl cellulose-chitosan (CMC-CS) blended membranes with different weight ratios(1:2, 1:1, 2:1) were prepared by co-solution method. The structure of membranes was characterized by FT-IR and SEM. The thermal property of membranes was characterized by DSC. The properties of CMC-CS were evaluated by uniformity, acid resistance, tensile strength and absorption rate. The intermolecular mechanism was analyzed. The results indicated that CMC and CS generated polyelec-trolyte through electrostatic and hydrogen-bond interactions. The intermolecule bonds of CMC-CS membranes were degraded between 170℃ and 330℃. At 217.4℃, the ionic bonds were fractured and the electrostatic interaction disappeared. The CMC-CS membrane with a weight ratio of 1:1 was the ideal membrane, whose electrostatic interaction between CS and CMC was the highest. Tensile strength of the CMC-CS membrane reached 34.44MPa, which was 64.47% higher than CS membrane. The maximal acid adaptability was decreased from pH value 5 to 4, and tensile strength of CMC-CS membrane was 25.71MPa after dunking at pH value 6. The water-swelling rate of CMC-CS membranes was effectively reduced.