细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶的性能表征

Performance characterization of bacterial cellulose reinforced polyvinyl alcohol/polyacrylamide composite hydrogels

背景:随着高分子水凝胶材料应用领域的扩展而对其性能提出了更高要求,研制和开发性能更为优良的高分子水凝胶材料已成为目前的研究热点。目的:比较细菌纤维素改性前后的聚乙烯醇/聚丙烯酰胺水凝胶的力学性能,为其用于伤口敷料提供理论依据。方法:实验利用细菌纤维素为增强材料,采用冷冻-熔融法,在细菌纤维素网络中引入聚乙烯醇/聚丙烯酰胺水凝胶,制备了细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶,采用红外光谱、扫描电镜、热重分析、力学性能测试等手段对凝胶的结构和性能进行表征。结果与结论:①通过扫描电镜和红外光谱图可以看到聚乙烯醇和聚丙烯酰胺结合到了细菌纤维素上,说明制备出了细菌纤维素/聚乙烯醇/聚丙烯酰胺复合水凝胶;②细菌纤维素增强复合凝胶的热稳定性、拉伸强度明显提高,而断裂伸长率较细菌纤维素增强前下降;③聚丙烯酰胺浓度为1.0%时,复合水凝胶的拉伸强度和断裂伸长率最大分别为331.79 kPa和105.33%,聚乙烯醇浓度为3.5%时,复合水凝胶的断裂伸长率最大为46.25%,而拉伸强度随聚乙烯醇浓度的增加而增加;④结果表明,细菌纤维素的引入明显提高了水凝胶材料的力学性能,增强了其稳定性,该复合水凝胶有望用作伤口敷料。

BACKGROUND:With the extension of the application of polymer hydrogel materials,to develop polymer hydrogel materials with better performance has become a hotspot.OBJECTIVE:To compare the mechanical properties of polyvinyl alcohol/polyacrylamide(PVA/PAM)composite hydrogel before and after modification by bacterial cellulose(BC),thereby providing a theoretic basis for its application in wound dressing.METHODS:BC-reinforced PVA/PAM hydrogels with different PVA/PAM contents were prepared using repeated freezing-thaw method.The BC/PVA/PAM hydrogels were characterized by infrared spectrum(IR)analysis,mechanical property test and scanning electron microscopy(SEM)observation,and thermogravimetric analysis.RESULTS AND CONCLUSION:SEM and IR results showed the PVA and PAM were combined and attached onto the surface of BC,indicating a success in the preparation of BC/PVA/PAM hydrogels.Results from the thermogravimetric analysis showed that the thermal-stability of the BC/PVA/PAM hydrogels improved significantly.The mechanical test results demonstrated that the tensile strength of the PVA/PAM hydrogels was strongly enhanced,and the elongation at break was significantly lowered after being reinforced with BC.Furthermore,the content of PVA and PAM had an obvious effect on the mechanical properties of the composites.When the PAM content was1.0%,the tensile strength and elongation at break of BC/PVA/PAM composites were at the highest level,which were331.79kPa and105.33%,respectively;when the PVA content was3.5%,the elongation at break of the BC/PVA/PAM composites was increased to the maximum(46.25%).Moreover,the results of this work reveal that the BC/PVA/PAM hydrogels exhibit some promising characteristics as artificial biomaterials.In general,the introduction of bacterial cellulose significantly improves the mechanical properties of the PVA/PAM hydrogels,and enhances the stability of the BC/PVA/PAM.