柠檬酸改性聚乙烯醇制备可生物降解膜的研究

Study on Biodegradable Memranes from Citric Acid Modified Polyvinyl Alcohol

选择柠檬酸(CA)作为单体在聚乙烯醇(PVA)水溶液中制备柠檬酸改性的聚乙烯醇交联聚合物,并用红外光谱表征膜的结构;重点考察了反应时间和反应温度对柠檬酸改性聚乙烯醇键合度的影响;使用淀粉与聚乙烯醇交联聚合物共混,制备了柠檬酸改性聚乙烯醇(CA-SP),并将其延流成膜,采用溶菌酶体外降解实验,测定CA-SP膜的降解性能,与柠檬酸键合量对生物降解的影响。测试了降解的CA-SP膜的力学性能考察。结果表明:柠檬酸的多羧基结构,能与PVA的羟基发生酯化,从而改性淀粉/聚乙烯醇(SP);在60℃下,反应3h时,柠檬酸的键合量可达到最大,为3.92g/g。使用溶菌酶对其进行降解,通过降解的失重率测定,发现柠檬酸的键合量越高,膜降解性能越好。柠檬酸改性的SP膜几乎可以达到完全降解。

The polyvinyl alcohol （PVA） cross-linked citric acid （CA） polymer membranes were made by using CA as monomer in PVA solution. The chemical composition was studied by infrared spectrometry （IR）. The effects of reaction time and temperature on bonding degree were investigated. The membranes by blend modification of starch and PVA were made and the degradation properties of the membranes were researched by lysozyme experiment. The mechanic properties of the CA/SP film after biodegradation were determined. The experimental results showed that the esterifieation reaction between CA and PVA is successfully taked place and the modified PVA is synthesized. The maximal content of CA could reach up to 3.92 g/g under 60 ℃ after 3 h. The degradation properties were studied by TG analysis. The higher the CA content is, the better the degradation property is. It is found that the PVA cross-linked CA could be mostly degraded.