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通过冷冻-熔融法制备了细菌纤维素/聚乙烯醇/聚乙烯吡咯烷酮(BC/PVA/PVP)双网络复合水凝胶,并采用X射线衍射,红外光谱,扫描电镜,力学性能测试等手段对凝胶的结构和性能进行表征.研究发现PVA、PVP通过氢键作用均匀地吸附于纤维微丝周围,将BC纤维有效地分开,因而干燥后的复合凝胶在热水中浸泡后仍可恢复原状;X射线衍射结果显示,直接干燥成膜样品和冻干样品的结晶性能差别明显,且PVA/PVP对BC的结晶有抑制作用,而BC增强复合凝胶中PVP对PVA结晶的影响作用与纯PVA/PVP体系类似,即少量PVP的存在对PVA的结晶有促进作用,浓度超过2%的PVP反而对PVA的结晶有抑制作用;力学性能测试结果表明,细菌纤维素的引入,明显地提高了水凝胶的压缩和拉伸性能,并且PVP,PVA含量的变化对材料的力学性能有较大影响;流变测试结果显示,BC增强后的凝胶的储能模量有很大提高,这与力学测试结果相一致.
Bacterial cellulose / polyvinyl alcohol / polyvinylpyrrolidone (BC / PVA / PVP) double network hydrogel was prepared by freeze-thaw method. XRD, IR, SEM and mechanical properties tests The structure and properties of the gel were characterized.The results showed that PVA and PVP adsorbed evenly around the microfilaments by hydrogen bonding and effectively separated the BC fibers so that the dried composite gel could still be recovered after soaking in hot water The results of X-ray diffraction showed that there were significant differences in the crystallization properties between the film of direct drying and the freeze-dried sample, and PVA / PVP inhibited the crystallization of BC, while BC enhanced the effect of PVP on the crystallization of PVA Pure PVA / PVP system is similar, that is, the presence of a small amount of PVP promote the crystallization of PVA, PVP concentration of more than 2% but inhibited the crystallization of PVA; mechanical properties test results showed that the introduction of bacterial cellulose, significantly increased The compressive and tensile properties of the hydrogels were also studied. The changes of PVP and PVA content had a great influence on the mechanical properties of the materials. The results of rheological tests showed that the storage modulus of the gels with BC enhanced greatly increased, This is a mechanical test The results are consistent.