层状纳米纤维素膜/PVA复合水凝胶的制备与力学性能研究

PREPARATION AND MECHANICAL PROPERTIES OF LAYERED BC NANO-CELLULOSE MEMBRANE/PVA COMPOSITE HYDROGELS

采用叠层复合与物理相分离的方法制备了层状纳米细菌纤维素(BC)膜/聚乙烯醇(PVA)复合水凝胶.研究了聚乙烯醇的质量百分数、BC膜的复合层数以及制备条件对复合水凝胶力学性能的影响;通过扫描电镜(SEM)观察比较了复合水凝胶中BC膜层与PVA界面结合情况.结果表明,复合水凝胶的力学性能与PVA的质量百分数和BC膜含水量、BC膜的层数以及制备条件有关.PVA质量百分数较高,流动性变差,界面结合差,导致复合水凝胶力学性能下降.当PVA质量百分数为15%、BC膜的层数为2层时,在相同的温度和条件下制备的复合水凝胶界面黏结良好,弹性模量、抗拉强度为7.82、1.74 MPa.

Bacterial nano-cellulose （BC） membranes of high purity, ultrafine network architecture and excellent biocompatibility were used to reinforce the poly （vinyl alcohol） （PVA） hydrogels, which were prepared by physical method of freezing and thawing. The mechanical properties of the BC/PVA composite hydrogels were investigated,the mass percent of PVA,the number of BC layers and some other conditions like pre-treatment method of BC membranes were considered in the preparation process. The mechanical properties of the BC/PVA composite hydrogels were tested by tensile testing machine, the fracture surface of the composite hydrogels and the bonding situation between the BC nano-cellulose membrane and the PVA hydrogel were characterized by the scanning electron microscopy （SEM）. The results show that the BC/PVA composite hydrogels have excellent mechanical properties,the tensile strength of the composite hydrogel reaches to 1.74 MPa,and the modulus reaches to 7.82 MPa,when the BC/PVA composite hydrogels are constituted by 15 wt% PVA and two layers of BC membranes. The SEM images show that the interface of the prepared composite hydrogels exhibits excellent bonding.